A Trophic State Analysis of Selected Water Bodies in Grand Teton National Park
Sean Castellano
A project report submitted to the faculty of
Brigham Young University
In partial fulfillment of the requirements for the degree of
Master of Science
A.Woodruff Miller, Chair
M. Brett Borup
E. James Nelson
Department of Civil and Environmental Engineering
Brigham Young University
August 2013
Copyright © 2013 Sean Castellano
All Rights Reserved
ABSTRACT
A Trophic State Analysis of Selected Water Bodies in Grand Teton National Park
Sean Castellano
Department of Civil and Environmental Engineering, BYU
Master of Science
In the year 1995, Dr. A. Woodruff Miller of Brigham Young University began collecting
water samples from selected lakes and streams in Grand Teton National Park on a yearly basis.
These samples have been used to determine the trophic state of the selected lakes. The first
purpose of this study is to determine the trophic state of each lake sampled for the year 2011.
The second purpose is to plot and observe trends in the trophic states of the various lakes using
the data collected from 1995 to present. Four water quality models are used to determine the
trophic state of each lake. The four models used in this report are the Carlson model, the Burns
model, the Vollenweider model and the Larsen-Mercier model. In 2011 the trophic states of the
select lakes of Teton National Park range from oligotrophic to eutrophic. Of the 14 bodies of
water sampled in 2011 there are three in which the deterioration of water quality is of most
concern. These three bodies of water are Cygnet Pond, Two Ocean Lake, and String Lake. This
conclusion is based on the fact that both the in-lake trophic state and inlet phosphorus trends are
increasing.
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iv
ACKNOWLEDGEMENTS
I would like to thank Dr. A. Woodruff Miller for allowing me to work on this project and
further my education here at Brigham Young University. I would also like to thank my parents
and grandparents who have always given me positive encouragement.
v
vi
TABLE OF CONTENTS
LIST OF TABLES ....................................................................................................................................... ix
LIST OF FIGURES ..................................................................................................................................... xi
1
INTRODUCTION ..................................................................................................................................... 1
1.1
Eutrophication ............................................................................................................................... 2
1.2
Trophic States ............................................................................................................................... 3
1.3
Water Quality Models and Methods ............................................................................................. 3
1.3.1
The Carlson Model................................................................................................................ 4
1.3.2
The Burns Model .................................................................................................................. 5
1.3.3
The Vollenweider Model ...................................................................................................... 6
1.3.4
The Larsen-Mercier Model ................................................................................................... 7
1.4
Carlson and Burns Model comparisons ........................................................................................ 8
2 TROPHIC STATE ANALYSIS FOR THE YEAR 2011 OF SELECTED LAKES IN GRAND
TETON NATIONAL PARK ...................................................................................................................... 11
2.1
Grand Teton National Park Maps and Photographs .................................................................... 12
2.2
Swan Lake South ........................................................................................................................ 20
2.3
Swan Lake North ........................................................................................................................ 25
2.4
Two Ocean Lake ......................................................................................................................... 28
2.5
Christian Pond............................................................................................................................. 32
2.6
Cygnet Pond ................................................................................................................................ 36
2.7
Emma Matilda Lake West........................................................................................................... 41
2.8
Oxbow Bend ............................................................................................................................... 44
2.9
Taggart Lake ............................................................................................................................... 47
2.10
Moose Pond ................................................................................................................................ 49
2.11
String Lake .................................................................................................................................. 52
2.12
Bradley Lake ............................................................................................................................... 56
2.13
Phelps Lake West ........................................................................................................................ 59
2.14
Arrowhead Pond ......................................................................................................................... 63
2.15
Ramshead Lake ........................................................................................................................... 67
2.16
Lake of the Crags ........................................................................................................................ 71
vii
3 TEMPORAL COMPARISON OF SELECTED LAKES AND PONDS IN GRAND TETON
NATIONAL PARK .................................................................................................................................... 77
3.1
Swan Lake South ........................................................................................................................ 77
3.2
Swan Lake North ........................................................................................................................ 82
3.3
Two Ocean Lake ......................................................................................................................... 86
3.4
Christian Pond............................................................................................................................. 91
3.5
Cygnet Pond ................................................................................................................................ 95
3.6
Emma Matilda Lake .................................................................................................................... 99
3.7
Oxbow Bend ............................................................................................................................. 103
3.8
Taggart Lake ............................................................................................................................. 105
3.9
Moose Pond .............................................................................................................................. 109
3.10
String Lake ................................................................................................................................ 112
3.11
Bradley Lake ............................................................................................................................. 115
3.12
Phelps Lake West ...................................................................................................................... 119
3.13
Lake of the Crags ...................................................................................................................... 123
4
CONCLUSIONS............................................................................................................................... 126
5
APPENDIX A. TABULATED DATA ............................................................................................. 133
A.1 Raw Data from 1995 through 2010 .............................................................................................. 133
viii
LIST OF TABLES
Table 1-1: Carlson TSI Classification Values.............................................................................................. 4
Table 1-2: Burns TLI Classification Values ................................................................................................ 6
Table 2-1: Trophic State Model Comparison for Swan Lake South in 2011 ............................................. 25
Table 2-2: Trophic State Model Comparison for Swan Lake North in 2011 ............................................. 28
Table 2-3: Trophic State Model Comparison for Two Ocean Lake in 2011 ............................................. 32
Table 2-4: Trophic State Model Comparison for Christian Pond in 2011 ................................................. 36
Table 2-5: Trophic State Model Comparison for Cygnet Pond in 2011 .................................................... 40
Table 2-6: Trophic State Model Comparison for Emma Matilda Lake in 2011 ........................................ 44
Table 2-7: Trophic State Model Comparison for Oxbow Bend in 2011 .................................................... 46
Table 2-8: Trophic State Model Comparison for Taggart Lake in 2011 ................................................... 48
Table 2-9: Trophic State Model Comparison for Moose Pond in 2011 ..................................................... 52
Table 2-10: Trophic State Model Comparison for String Lake in 2011 .................................................... 56
Table 2-11: Trophic State Model Comparison for Bradley Lake in 2011 ................................................. 58
Table 2-12: Trophic State Model Comparison for Phelps Lake in 2011 ................................................... 62
Table 2-13: Overview of Arrowhead Pond ................................................................................................ 63
Table 2-14: Trophic State Model Comparison for Arrowhead Pond in 2011 ............................................ 66
Table 2-15: Overview of Ramshead Lake ................................................................................................. 67
Table 2-16: Trophic State Model Comparison for Ramshead Lake in 2011 ............................................. 70
Table 2-17: Trophic State Model Comparison for Lake of the Crags in 2011 .......................................... 74
Table 3-1: Overview of Swan Lake South ................................................................................................. 77
Table 3-2: Overview of Swan Lake North ................................................................................................. 82
Table 3-3: Overview of Two Ocean Lake ................................................................................................. 86
Table 3-4: Overview of Christian Pond ..................................................................................................... 91
Table 3-5: Overview of Cygnet Pond ........................................................................................................ 95
Table 3-6: Overview of Emma Matilda Lake ............................................................................................ 99
Table 3-7: Overview of Oxbow Bend ...................................................................................................... 103
Table 3-8: Overview of Taggart Lake...................................................................................................... 105
Table 3-9: Overview of Moose Pond ....................................................................................................... 109
Table 3-10: Overview of String Lake ...................................................................................................... 112
Table 3-11: Overview of Bradley Lake ................................................................................................... 115
Table 3-12: Overview of Phelps Lake ..................................................................................................... 119
Table 3-13: Overview of Lake of the Crags ............................................................................................ 123
Table 4-1: 2011 Trophic States ................................................................................................................ 126
Table 4-2: 2011 Trophic States and Corresponding Elevations............................................................... 127
Table 4-3: In-Lake Trophic State Trends ................................................................................................. 128
Table 4-4: Inlet Phosphorus Trends ......................................................................................................... 129
Table 4-5: In-Lake and Inlet Trend Explanations .................................................................................... 130
Table 5-1: Raw Data for Swan Lake South ............................................................................................. 134
Table 5-2: Raw Data for Swan Lake North ............................................................................................. 136
ix
Table 5-3: Raw Data for Two Ocean Lake .............................................................................................. 138
Table 5-4: Raw Data for Christian Pond .................................................................................................. 140
Table 5-5: Raw Data for Cygnet Pond ..................................................................................................... 142
Table 5-6: Raw Data for Emma Matilda Lake ......................................................................................... 143
Table 5-7: Raw Data for Oxbow Bend .................................................................................................... 144
Table 5-8: Raw Data for Taggart Lake .................................................................................................... 145
Table 5-9: Raw Data for Moose Pond ..................................................................................................... 145
Table 5-10: Raw Data for String Lake ..................................................................................................... 146
Table 5-11: Raw Data for Bradley Lake .................................................................................................. 147
Table 5-12: Raw Data for Phelps Lake .................................................................................................... 147
Table 5-13: Raw Data for Arrowhead Pond ............................................................................................ 148
Table 5-14: Raw Data for Ramshead Lake .............................................................................................. 149
Table 5-15: Raw Data for Lake of the Crags ........................................................................................... 149
x
LIST OF FIGURES
Figure 1-1: Vollenweider Model Template ................................................................................................. 7
Figure 1-2: Larsen Mercier Model Template ............................................................................................... 8
Figure 2-1: Location of Grand Teton National Park .................................................................................. 12
Figure 2-2: Location of Selected Lakes and Ponds in Grand Teton National Park ................................... 13
Figure 2-3: Ramshead Lake ....................................................................................................................... 14
Figure 2-4: Phelps Lake ............................................................................................................................. 15
Figure 2-5: Bradley Lake ........................................................................................................................... 16
Figure 2-6: String Lake .............................................................................................................................. 17
Figure 2-7: Oxbow Bend ........................................................................................................................... 18
Figure 2-8: Christian Pond ......................................................................................................................... 19
Figure 2-9: Swan Lake ............................................................................................................................... 20
Figure 2-10: Carlson Trophic State Indices for Swan Lake South in 2011 ............................................... 21
Figure 2-11: Comparison of Carlson and Burns Trophic States for Swan Lake South in 2011 ................ 22
Figure 2-12: Vollenweider Model for Swan Lake South in 2011 .............................................................. 23
Figure 2-13: Larsen Mercier Model for Swan Lake South in 2011 ........................................................... 24
Figure 2-14: Carlson Trophic State Indices for Swan Lake North in 2011 ............................................... 26
Figure 2-15: Comparison of Carlson and Burns Trophic States for Swan Lake North in 2011 ................ 27
Figure 2-16: Carlson Trophic State Indices for Two Ocean Lake in 2011 ................................................ 29
Figure 2-17: Comparison of Carlson and Burns Trophic States for Two Ocean Lake in 2011 ................. 30
Figure 2-18: Vollenweider Model for Two Ocean Lake in 2011 .............................................................. 31
Figure 2-19: Larsen Mercier Model for Two Ocean Lake in 2011............................................................ 31
Figure 2-20: Carlson Trophic State Indices for Christian Pond in 2011 .................................................... 33
Figure 2-21: Comparison of Carlson and Burns Trophic States for Christian Pond in 2011 .................... 34
Figure 2-22: Vollenweider Model for Christian Pond in 2011 .................................................................. 35
Figure 2-23: Larsen Mercier Model for Christian Pond in 2011 ............................................................... 35
Figure 2-24: Carlson Trophic State Indices for Cygnet Pond in 2011 ....................................................... 37
Figure 2-25: Comparison of Carlson and Burns Trophic States for Cygnet Pond in 2011........................ 38
Figure 2-26: Vollenweider Model for Cygnet Pond in 2011 ..................................................................... 39
Figure 2-27: Larsen Mercier Model for Cygnet Pond in 2011 .................................................................. 40
Figure 2-28: Carlson Trophic State Indices for Emma Matilda Lake in 2011........................................... 41
Figure 2-29: Comparison of Carlson and Burns Trophic States for Emma Matilda Lake in 2011............ 42
Figure 2-30: Vollenweider Model for Emma Matilda Lake in 2011 ......................................................... 43
Figure 2-31: Larsen Mercier Model for Emma Matilda Lake in 2011 ...................................................... 43
Figure 2-32: Carlson Trophic State Indices for Oxbow Bend in 2011 ...................................................... 45
Figure 2-33: Comparison of Carlson and Burns Trophic States for Oxbow Bend in 2011 ....................... 46
Figure 2-34: Carlson Trophic State Indices for Taggart Lake in 2011 ...................................................... 47
Figure 2-35: Comparison of Carlson and Burns Trophic States for Taggart Lake in 2011 ....................... 48
Figure 2-36: Carlson Trophic State Indices for Moose Pond in 2011 ....................................................... 49
Figure 2-37: Comparison of Carlson and Burns Trophic States for Moose Pond in 2011 ........................ 50
xi
Figure 2-38: Vollenweider Model for Moose Pond in 2011 ...................................................................... 51
Figure 2-39: Larsen Mercier Model for Moose Pond in 2011 ................................................................... 51
Figure 2-40: Carlson Trophic State Indices for String Lake in 2011 ......................................................... 53
Figure 2-41: Comparison of Carlson and Burns Trophic States for String Lake in 2011 .......................... 54
Figure 2-42: Vollenweider Model for String Lake in 2011 ....................................................................... 54
Figure 2-43: Larsen Mercier Model for String Lake in 2011 .................................................................... 55
Figure 2-44: Carlson Trophic State Indices for Bradley Lake in 2011 ...................................................... 57
Figure 2-45: Comparison of Carlson and Burns Trophic States for Bradley Lake in 2011 ....................... 58
Figure 2-46: Carlson Trophic State Indices for Phelps Lake in 2011 ........................................................ 59
Figure 2-47: Comparison of Carlson and Burns Trophic States for Phelps Lake in 2011 ......................... 60
Figure 2-48: Vollenweider Model for Phelps Lake in 2011 ...................................................................... 61
Figure 2-49: Larsen Mercier Model for Phelps Lake in 2011 ................................................................... 62
Figure 2-50: Carlson Trophic State Indices for Arrowhead Pond in 2011 ................................................ 63
Figure 2-51: Comparison of Carlson and Burns Trophic States for Arrowhead Pond in 2011 ................. 64
Figure 2-52: Vollenweider Model for Arrowhead Pond in 2011 ............................................................... 65
Figure 2-53: Larsen Mercier Model for Arrowhead Pond in 2011 ............................................................ 66
Figure 2-54: Carlson Trophic State Indices for Ramshead Lake in 2011 .................................................. 67
Figure 2-55: Comparison of Carlson and Burns Trophic States for Ramshead Lake in 2011 ................... 68
Figure 2-56: Vollenweider Model for Ramshead Lake in 2011 ................................................................ 69
Figure 2-57: Larsen Mercier Model for Ramshead Lake in 2011 ............................................................. 70
Figure 2-58: Carlson Trophic State Indices for Lake of the Crags in 2011 ............................................... 71
Figure 2-59: Comparison of Carlson and Burns Trophic States for Lake of the Crags in 2011 ................ 72
Figure 2-60: Vollenweider Model for Lake of the Crags in 2011 ............................................................. 73
Figure 2-61: Larsen Mercier Model for Lake of the Crags in 2011........................................................... 74
Figure 3-1: Total TSI Trend for Swan Lake South in the Month of June ................................................. 78
Figure 3-2: Total TSI Trend for Swan Lake South in the Month of July .................................................. 78
Figure 3-3: Total TSI Trend for Swan Lake South in the Month of August.............................................. 79
Figure 3-4: Total TSI Trend for Swan Lake South in the Month of October ............................................ 79
Figure 3-5: Total TSI Trend for Swan Lake South for all Available Data ................................................ 80
Figure 3-6: Total Inlet Phosphorus Concentrations for Swan Lake South ................................................ 80
Figure 3-7: Phosphorus and Chlorophyll-a Concentrations for Swan Lake South .................................... 81
Figure 3-8: Total TSI Trend for Swan Lake North in the Month of June ................................................. 82
Figure 3-9: Total TSI Trend for Swan Lake North in the Month of July .................................................. 83
Figure 3-10: Total TSI Trend for Swan Lake North in the Month of August............................................ 83
Figure 3-11: Total TSI Trend for Swan Lake North in the Month of October .......................................... 84
Figure 3-12: Total TSI Trend for Swan Lake North for all Available Data .............................................. 84
Figure 3-13: Total Inlet Phosphorus Concentrations for Swan Lake North .............................................. 85
Figure 3-14: Phosphorus and Chlorophyll-a Concentrations for Swan Lake North .................................. 86
Figure 3-15: Total TSI Trend for Two Ocean Lake in the Month of June ................................................ 87
Figure 3-16: Total TSI Trend for Two Ocean Lake in the Month of July ................................................. 87
Figure 3-17: Total TSI Trend for Two Ocean Lake in the Month of August ............................................ 88
Figure 3-18: Total TSI Trend for Two Ocean Lake in the Month of October ........................................... 88
xii
Figure 3-19:
Figure 3-20:
Figure 3-21:
Figure 3-22:
Figure 3-23:
Figure 3-24:
Figure 3-25:
Figure 3-26:
Figure 3-27:
Figure 3-28:
Figure 3-29:
Figure 3-30:
Figure 3-31:
Figure 3-32:
Figure 3-33:
Figure 3-34:
Figure 3-35:
Figure 3-36:
Figure 3-37:
Figure 3-38:
Figure 3-39:
Figure 3-40:
Figure 3-41:
Figure 3-42:
Figure 3-43:
Figure 3-44:
Figure 3-45:
Figure 3-46:
Figure 3-47:
Figure 3-48:
Figure 3-49:
Figure 3-50:
Figure 3-51:
Figure 3-52:
Figure 3-53:
Figure 3-54:
Figure 3-55:
Figure 3-56:
Figure 3-57:
Figure 3-58:
Figure 3-59:
Figure 3-60:
Total TSI Trend for Two Ocean Lake for all Available Data ............................................... 89
Total Inlet Phosphorus Concentrations for Two Ocean Lake ............................................... 89
Phosphorus and Chlorophyll-a Concentrations for Two Ocean Lake ................................... 90
Total TSI Trend for Christian Pond in the Month of June .................................................... 91
Total TSI Trend for Christian Pond in the Month of July ..................................................... 92
Total TSI Trend for Christian Pond in the Month of August ................................................ 92
Total TSI Trend for Christian Pond in the Month of October............................................... 93
Total TSI Trend for Christian Pond for all Available Data................................................... 93
Total Inlet Phosphorus Concentrations for Christian Pond ................................................... 94
Phosphorus and Chlorophyll-a Concentrations for Christian Pond ...................................... 95
Total TSI Trend for Cygnet Pond in the Month of June ....................................................... 96
Total TSI Trend for Cygnet Pond in the Month of July ........................................................ 96
Total TSI Trend for Cygnet Pond in the Month of August ................................................... 97
Total TSI Trend for Cygnet Pond for all Available Data ...................................................... 97
Total Inlet Phosphorus Concentrations for Cygnet Pond ...................................................... 98
Phosphorus and Chlorophyll-a Concentrations for Cygnet Pond ......................................... 99
Total TSI Trend for Emma Matilda Lake in the Month of June ......................................... 100
Total TSI Trend for Emma Matilda Lake in the Month of August ..................................... 100
Total TSI Trend for Emma Matilda Lake in the Month of October.................................... 101
Total TSI Trend for Emma Matilda Lake for all Available Data ........................................ 101
Total Inlet Phosphorus Concentrations for Emma Matilda Lake ........................................ 102
Phosphorus and Chlorophyll-a Concentrations for Emma Matilda Lake ........................... 103
Total TSI Trend for Oxbow Bend in the Month of October ............................................... 104
Total TSI Trend for Oxbow Bend for all Available Data ................................................... 104
Phosphorus and Chlorophyll-a Concentrations for Oxbow Bend ....................................... 105
Total TSI Trend for Taggart Lake in the Month of June .................................................... 106
Total TSI Trend for Taggart Lake in the Month of August ................................................ 106
Total TSI Trend for Taggart Lake in the Month of October ............................................... 107
Total TSI Trend for Taggart Lake for all Available Data ................................................... 107
Total Inlet Phosphorus Concentrations for Taggart Lake ................................................... 108
Phosphorus and Chlorophyll-a Concentrations for Taggart Lake ....................................... 108
Total TSI Trend for Moose Pond in the Month of June ...................................................... 109
Total TSI Trend for Moose Pond in the Month of October ................................................ 110
Total TSI Trend for Moose Pond for all Available Data .................................................... 110
Total Inlet Phosphorus Concentrations for Moose Pond..................................................... 111
Phosphorus and Chlorophyll-a Concentrations for Moose Pond ........................................ 111
Total TSI Trend for String Lake in the Month of June ....................................................... 113
Total TSI Trend for String Lake for all Available Data ...................................................... 113
Total Inlet Phosphorus Concentrations for String Lake ...................................................... 114
Phosphorus and Chlorophyll-a Concentrations for String Lake ......................................... 114
Total TSI Trend for Bradley Lake in the Month of June .................................................... 116
Total TSI Trend for Bradley Lake in the Month of August ................................................ 116
xiii
Figure 3-61:
Figure 3-62:
Figure 3-63:
Figure 3-64:
Figure 3-65:
Figure 3-66:
Figure 3-67:
Figure 3-68:
Figure 3-69:
Figure 3-70:
Figure 3-71:
Total TSI Trend for Bradley Lake in the Month of October ............................................... 117
Total TSI Trend for Bradley Lake for all Available Data ................................................... 117
Total Inlet Phosphorus Concentrations for Bradley Lake ................................................... 118
Phosphorus and Chlorophyll-a Concentrations for Bradley Lake....................................... 118
Total TSI Trend for Phelps Lake in the Month of June ...................................................... 120
Total TSI Trend for Phelps Lake in the Month of August .................................................. 120
Total TSI Trend for Phelps Lake for all Available Data ..................................................... 121
Total Inlet Phosphorus Concentrations for Phelps Lake ..................................................... 121
Phosphorus and Chlorophyll-a Concentrations for Phelps Lake......................................... 122
Total TSI Trend for Lake of the Crags in the Month of June ............................................. 123
Total TSI Trend for Lake of the Crags for all Available Data ............................................ 124
xiv
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1
INTRODUCTION
In 1995 Dr. A. Woodruff Miller of Brigham Young University began collecting water
samples from selected lakes in Grand Teton National Park. These water samples were
subsequently tested for specific parameters. These parameters include phosphorus and
chlorophyll-a concentrations. Trophic states for each lake were then determined using these two
parameters along with a transparency measurement. Dr. Miller and his students have been using
the data collected since 1995 to classify the trophic states and health of various lakes in Grand
Teton National Park. The goal of this project has been to observe trends in the trophic states, and
thus the water quality, of the various lakes in Grand Teton National Park.
The trophic state represents the nutrient levels of each lake and corresponding biological
growth. “The concept of trophic status is based on the fact that changes in nutrient levels
(measured by total phosphorus) causes changes in algal biomass (measured by chlorophyll a)
which in turn causes changes in lake clarity (measured by Secchi disk transparency)” (EPA,
2009). The concept of trophic state will be explained later in this report.
There are many different water quality models that have been developed with the purpose
of quantifying the water quality of a given body of water. Dr. Miller and his team have selected
the most relevant models to determine the water quality of the selected lakes in Grand Teton
National Park. The models used in this study are the Carlson Model, the Burns Model, the
Vollenweider Model, and the Larsen-Mercier Model.
There are two main components of this report. The first component is to measure the
trophic states of selected lakes in Grand Teton National Park for the year 2011. The second
component is to observe the long term temporal trends that exist in the collected data. The
temporal trends reported in this study come from two main sources of data. The first source of
data is from the in-lake measurements of phosphorus and chlorophyll-a. The second source of
data is from the inlet phosphorus measurements. The temporal trends of the Carlson Model
results are first analyzed on a monthly and overall basis. The overall inlet phosphorus trend for a
particular lake is then analyzed.
This report is intended to serve as a management tool for the United States National Parks
Service. This report will also aid in making model comparisons and in predicting the water
quality of the select lakes.
1
1.1
Eutrophication
Eutrophication occurs as the dissolved oxygen in a lake is reduced and as less complex
organisms become the majority of a lake ecosystem. The process of eutrophication is complex
and occurs through multiple physical and biological processes. Eutrophication can occur as a
natural process and take thousands of years. The eutrophication process can also be shortened by
human interaction.
The physical characteristics of a lake contribute to the specific biological and physical
processes that occur in a lake. A deep lake is typically divided into three sections or zones which
include an upper, middle and lower section. The upper section is called the epilimnion, the
middle section is called the metalimnion and the lowest section is called the hypolimnion. A
temperature gradient with respect to depth often exists in a lake. “Circulation of water occurs
only within a zone and thus there is only limited transfer of biological or chemical material
across the boundaries.” (Vesilind, 1994). The temperature-density relationship of water often
causes mixture between the zones as the temperature of the epilimnion increases to 4 C and
becomes denser. This process is known as fall turnover.
Another physical characteristic which influences the process of eutrophication is the amount
of light which penetrates the surface of a lake. The penetration of light in a lake is logarithmic.
The intensity of light is greatest at the very upper portion of the lake and decreases with depth.
“Light usually penetrates only the top 2 feet of a lake; hence, all photosynthetic reactions occur
in that zone.” (Vesilind, 1994).
Several types of organisms contribute to the eutrophication process of a lake. The
microorganisms in a lake perhaps play the largest role in the eutrophication of a lake. Algae,
phytoplankton and decomposing bacteria are all microorganisms which heavily affect the
process of eutrophication in a lake. Fish and zooplankton can also exist in the ecosystem of a
lake and can have an effect on eutrophication.
Algae and phytoplankton use sunlight as a form of energy along with other nutrients to create
high-energy compounds. The nutrients used by the algae and phytoplankton include
phosphorus, nitrogen and carbon. Algae are an important part of the ecosystem of a lake because
they provide oxygen to a lake. Algae are also a food resource for tiny aquatic animals called
zooplankton. Zooplanktons are a food source for larger organisms such as fish. The waste
byproducts from these organisms contribute to the amount of dissolved organic carbon within a
lake. The death of all these organisms mentioned also contributes to this organic carbon. The
decomposing bacteria use this carbon source as well as dissolved oxygen for energy and
reproduction.
As increased amounts of phosphorus, nitrogen and carbon are introduced into a lake the rate
of algae reproduction is increased. When algae die it sinks and becomes a source of carbon for
2
the decomposing bacteria. The dissolved oxygen in the hypolimnion can ultimately disappear as
bacteria use this carbon source and dissolved oxygen for energy and reproduction. This process
can progress towards the surface of a lake until the metalimnion also becomes anaerobic. “The
aerobic biological activity produces turbidity, decreasing light penetration and in turn limiting
photosynthetic algal activity in the surface layers.” (Vesilind, 1994). This process decreases the
amount of dissolved oxygen that algae contribute to a lake. Eventually the epilimnion also
becomes anaerobic and all aerobic aquatic life disappears. Algae blooms can then continue
occurring on the very surface of a lake. This process along with algal death can eventually fill
the lake and create a peat bog.
One of the main mechanisms for eutrophication is the growth of algae. Algae can quickly
assimilate phosphorus, nitrogen and carbon to reproduce. “Generally, a phosphorus: nitrogen:
carbon ratio of 1:16:100 is required for algal growth.” (Vesilind, 1994). Phosphorus however, is
often the limiting nutrient in a lake. Addition of phosphorus can therefore speed up the
eutrophication process.
1.2
Trophic States
A trophic state categorizes a lake into one of four possible classifications. Each classification
represents the point or stage of eutrophication which a particular lake is experiencing at a
specific time. These classifications are oligotrophic, mesotrophic, eutrophic and hypereutrophic. An oligotrophic lake has low levels of nutrients and high levels of dissolved oxygen.
Dissolved oxygen is not one of the calculated parameters in this report but high levels of
dissolved oxygen are the result of low levels of biomass. A eutrophic lake represents a lake that
has high nutrient levels and has progressed further in the process of eutrophication. The high
nutrient levels of a eutrophic lake promote algal blooms and tend to have low visibility. A
mesotrophic lake falls somewhere between the oligotrophic and eutrophic classifications. The
trophic state classification of a lake is a convenient way to assess its water quality.
1.3
Water Quality Models and Methods
This section describes the models which were used to determine the trophic states of the
selected lakes of Grand Teton National Park.
3
1.3.1 The Carlson Model
The Carlson Model was developed by Dr. Robert Carlson, a professor at Kent State
University. The Carlson Model is made up of three equations which classify a water body by
trophic state. There are three indicators or parameters which the Carlson Model uses as input
variables. These three indicators are phosphorus concentration, chlorophyll-a concentration, and
secchi depth. Equations 1-1 through 1-3 are the equations that define the Carlson Model.
(1-1)
(1-2)
(1-3)
The output Trophic State Index (TSI) values from these three equations are averaged to
determine a trophic state index which corresponds to a specific trophic state. As previously
stated, the trophic state classifications are oligotrophic, mesotrophic, eutrophic and hypereutrophic. When the averaged or Total TSI value is between one of the four major trophic states
a sub classification of “slightly” or “strongly” is applied to the trophic state name. The following
table shows the scale used to assign trophic states to different Total TSI values.
Table 1-1: Carlson TSI Classification Values
Classification
Scale
Strongly Oligotrophic
27 > TSI
Oligotrophic
Slightly Oligotrophic
Slightly Mesotrophic
Mesotrophic
Strongly Mesotrophic
Slightly Eutrophic
Eutrophic
Strongly Eutrophic
33 > TSI > 27
38 > TSI > 33
43 > TSI > 38
49 > TSI > 43
54 > TSI > 49
58 > TSI > 54
62 > TSI > 58
65 > TSI > 62
Slightly Hyper-Eutrophic
Hyper-Eutrophic
70 > TSI > 65
TSI > 70
4
1.3.2 The Burns Model
The Burns Model was developed to classify a variety of lakes in New Zealand. The Burns
Model has also been applied to lakes and reservoirs in the United States. (Burns et al., 1999). The
Burns Model is similar to the Carlson Model in that it is dependent on the phosphorus
concentration, chlorophyll-a concentration and secchi depth. The Burns Model also considers
the nitrogen concentration. The Burns Model uses these four parameters to calculate a value
called the Total Trophic Level Index (TLI). The following equations govern the Total TLI value
for a given body of water.
(1-4)
(1-5)
(1-6)
(1-7)
(1-8)
Nitrogen concentrations were not measured in this study. The previous equation was
modified in order to account for this fact.
(1-9)
The Trophic Level indices of the Burns Model are ultra-microtrophic, microtrophic,
oligotrophic, mesotrophic, eutrophic, supertrophic, and hypertrophic. This terminology of the
Burns Model was modified to better compare the Burns Model with the Carlson Model. The
Burns Model classification scale of the Trophic Level Indices is shown in the following table.
5
Table 1-2: Burns TLI Classification Values
Classification
Strongly Oligotrophic
Oligotrophic
Slightly Oligotrophic
Slightly Mesotrophic
Mesotrophic
Strongly Mesotrophic
Slightly Eutrophic
Eutrophic
Strongly Eutrophic
Slightly Hyper-Eutrophic
Hyper-Eutrophic
1.3.3
Scale
2.0 > TSI
2.7 > TSI > 2.0
3.0 > TSI > 2.7
3.3 > TSI > 3.0
3.7 > TSI > 3.3
4.0 > TSI > 3.7
4.5 > TSI > 4.0
5.0 > TSI > 4.5
5.5 > TSI > 5.0
6.0 > TSI > 5.5
TSI > 6.0
The Vollenweider Model
The Vollenweider Model was developed to study deep lakes in the Northern Hemisphere.
(Vollenweider 1968). The Vollenweider Model is applied with the use of a graph which relates
the hydraulic residence time and inflow phosphorus concentration to a trophic state. The
hydraulic residence time is plotted on the abscissa and the inflow phosphorus concentration is
plotted on the ordinate. The hydraulic residence times for the selected lakes in Grand Teton
National Park were estimated by dividing the lake volume by the average inlet flow. A
Vollenweider Model graph is shown in Figure 1-1.
6
1000
Inflow Total Phosphorus Conc. (ppb)
Hyper-eutrophic
Eutrophic
100
Mesotrophic
Oligotrophic
10
1
0.01
0.1
1
Hydraulic Residence Time (years)
10
100
Figure 1-1: Vollenweider Model Template
The Vollenweider model classifies the trophic state to be oligotrophic, mesotrophic,
eutrophic, or hyper-eutrophic. When a plotted hydraulic residence time and corresponding
inflow phosphorus concentration is near one of the major trophic state divisions the sub
classification of “slightly” or “strongly” is applied to the trophic state name. These subclassifications allows for comparison across all four models used in this study. The
Vollenweider model was not used for all of the lakes in this study due to the lack of inlet
phosphorus measurements at some of the lakes.
1.3.4 The Larsen-Mercier Model
The Larsen Mercier Model is a model which is also based on the amount of phosphorus
entering a lake. This model differs from the Vollenweider Model in that it accounts for the
amount of phosphorus retained in the lake. The parameter used to describe this process is the
phosphorus retention coefficient. The Larsen Mercier Model also uses a graph to categorize a
lake into a trophic state. The phosphorus retention coefficient is plotted on the abscissa and the
inflow phosphorus concentration is plotted on the ordinate. Figure 1-2 shows the graph used in
the Larsen Mercier Model.
The phosphorus retention coefficient is calculated by subtracting the outflow
concentration from the inflow concentration and dividing this difference by the inflow
phosphorus concentration. The in-lake phosphorus concentration values were used as the outlet
7
phosphorus concentration values. The phosphorus retention coefficient takes the amount of
phosphorus retained by the lake into consideration.
The trophic states calculated from this model are oligotrophic, mesotrophic and
eutrophic. Sub classifications were given to lakes which bordered the division between two of
these three trophic states for this model as well as the Vollenweider Model.
Figure 1-2: Larsen Mercier Model Template
1.4
Carlson and Burns Model comparisons
In general the Burns Model produces higher TSI values, especially in the mesotrophic to
eutrophic range. However, as each model produces TSI values in the oligotrophic range the
difference becomes smaller. This is due to the equations that define the Carlson and Burns
Models.
To compare the Carlson and Burns Models a normalized trophic level was applied to
each model. After determining the TSI and TLI values for each lake the normalized trophic
levels could be calculated. Each TSI or TLI value fell into a specific range of values, which are
shown in Table 1-1 and Table 1-2. The lower limits of these ranges were subtracted from the
TSI and TLI values and then divided by the range into which they fell. This would determine a
trophic state percentage. This percentage was then added to a rank. Strongly Oligotrophic was
assigned a rank of 0.1 and Hyper Eutrophic was assigned a rank of 1.1. Each sub classification
ranked increased by 0.1. The percentages were added to these ranks. For example if a Burns
8
TLI fell into the middle of the oligotrophic range then it would be 50% oligotrophic. A value of
0.05 was then added to the rank of oligotrophic which rank was assigned to be 0.2. The
normalized value for this lake would then be 0.25. The plots comparing Carlson and Burns
trophic states were created using this method.
9
10
2
TROPHIC STATE ANALYSIS FOR THE YEAR 2011 OF SELECTED LAKES IN
GRAND TETON NATIONAL PARK
From the month of June to October of 2011 there were a total of 14 bodies of water sampled
in Grand Teton National Park. Nine of these bodies of water sampled were lakes, four were
ponds and one was an oxbow formed in the Snake River. Swan Lake was sampled at two
locations; one at the north side and one at the south side of the lake. In-lake samples were taken
from each of the 14 bodies of water. The inlets of 11 of these bodies of water were also sampled
for phosphorus concentration.
The recorded secchi depths used in the Carlson and Burns models are estimates. These data
were measured visually. It is assumed that the estimates for secchi depth are accurate to about 1
foot. The total TSI due to secchi depth is therefore considered as the least accurate measurement
in the Carlson and Burns models.
“The environmental laboratory that processed the water samples reported phosphorus
concentrations down to 10 parts per billion.” The samples that had less than 10 parts per billion
were reported as trace amounts. To include these values in the Carlson and Burns model
equations a value of 10 ppb was used.
Trophic states of all 14 bodies of water were calculated with the Carlson and Burns Models.
The Vollenweider and Larsen-Mercier Models require the inlet phosphorus concentration as
input; therefore only 11 of these 14 bodies of water were analyzed using the Vollenweider and
Larsen Mercier models. A trophic state for each body of water was calculated by averaging the
trophic state results from each model.
The lakes shown in Figures 2-3 through 2-9 are in order of increasing trophic state.
Therefore, Ramshead Lake shown in Figure 2-3 has the lowest trophic state (oligotrophic), and
Swan Lake shown in Figure 2-9 has the highest trophic state. The lakes subsequently presented
in sections 2.2 through 2.16 are in order of decreasing trophic state. Swan Lake South presented
in section 2.2 had the highest trophic state in 2011and Lake of the Crags had the lowest trophic
state in 2011.
11
2.1
Grand Teton National Park Maps and Photographs
Figure 2-1: Location of Grand Teton National Park
(maps.google.com)
12
Figure 2-2: Location of Selected Lakes and Ponds in Grand Teton National Park
(maps.google.com)
13
Figure 2-3: Ramshead Lake
(jacksonholewy.net)
14
Figure 2-4: Phelps Lake
(americansouthwest.net)
15
Figure 2-5: Bradley Lake
(jacksonholewy.net)
16
Figure 2-6: String Lake
(flickr.com)
17
Figure 2-7: Oxbow Bend
(rvcruzer.com)
18
Figure 2-8: Christian Pond
(flickr.com)
19
Figure 2-9: Swan Lake
(hiking.about.com)
2.2
Swan Lake South
In 2011 samples were collected for the south side of Swan Lake during the months of June,
July, August and October. Trophic State analysis has been performed on the south side of Swan
Lake over the following years: 1995, 1996, 1997, 2000, 2003, 2004, 2005, 2006, 2007, 2008,
2009, 2010, and 2011. The Inlet of Swan Lake has been sampled in 1995, 1996, 1997, 2002,
2003, 2004, 2007, 2008, 2009, 2010 and 2011.
Figure 2-10 shows the trophic state indices in June, July, August and October for the south
side of Swan Lake in 2011.
20
Figure 2-10: Carlson Trophic State Indices for Swan Lake South in 2011
The Carlson model produced trophic states ranging from mesotrophic to eutrophic for the
south side of Swan Lake. The trophic state values for the south side of Swan Lake for June, July,
August and October were 47.3, 57.3, 49.7, and 48.9 respectively. These values correspond to
trophic states classifications of mesotrophic, slightly eutrophic, strongly mesotrophic and
mesotrophic for the months June, July, August and October respectively.
The Burns model was also used to calculate trophic level indices for the south side of
Swan Lake in 2011. The trophic level values for the south side of Swan Lake were 3.9, 5.0, 4.3,
and 4.2 for the months of June through October respectively, excluding September. These
values correspond to trophic state classifications of strongly mesotrophic, eutrophic, slightly
eutrophic, and slightly eutrophic for the months of June through October excluding September.
The Carlson and Burns model trophic values for 2011 were normalized and compared in Figure
2-11.
21
1.0
0.9
Eutrophic
Normalized Trophic Level
0.8
0.7
0.6
0.5
Mesotrophic
Carlson
0.4
Burns
0.3
0.2
Oligotrophic
0.1
0.0
May-11
June-11
July-11
August-11 September-11 October-11 November-11
Figure 2-11: Comparison of Carlson and Burns Trophic States for Swan Lake South in 2011
This graph is used to observe the trophic state trends and to compare the calculated
trophic states. Both Models follow a nearly identical trend with the Burns Model producing
higher values for every month. The highest trophic state occurred during the month of August.
The Vollenweider and Larsen-Mercier models were also used to evaluate the trophic state
of the south side of Swan Lake in 2011. Figure 2-12 shows the Vollenweider model trophic state
values for June, July, August and October.
22
Figure 2-12: Vollenweider Model for Swan Lake South in 2011
The inflow phosphorus concentration into Swan Lake was large compared to the rest of
the lakes sampled in the Teton Lakes area. A trophic state varying from Eutrophic to Hypereutrophic was calculated for Swan Lake using the Vollenweider model. The trophic state for
October was strongly eutrophic. The trophic states for June through August were hypereutrophic.
The high inflow phosphorus concentration into Swan Lake produced a relatively high
trophic state value using the Larsen Mercier model as well. The trophic states are not as high as
the trophic states calculated with the Vollenweider model however. The amount of phosphorus
retained in Swan Lake resulted in lower trophic state values when using the Larsen Mercier
method. The Larsen Mercier Model results are shown in Figure 2-13 with trophic state values
for June through October, excluding September.
23
Figure 2-13: Larsen Mercier Model for Swan Lake South in 2011
The trophic states using the Larsen Mercier model were strongly eutrophic, slightly
eutrophic, mesotrophic, and eutrophic for the months of June, July, August and October
respectively. The lowest trophic state for the south side of Swan Lake occurred in August for all
models except the Vollenweider Model. This is because the Vollenweider Model neglects any
in-lake measurements.
We can see from Table 2-1, that the Carlson Model gave the lowest trophic state values for
the south side of Swan Lake. The Larsen Mercier and Vollenweider Models produced higher
trophic states because they account for the inlet phosphorus concentrations which were higher
than the in-lake phosphorus concentrations. Averaging all trophic state values for all models and
months results in a eutrophic trophic state of for the south side of Swan Lake in 2011.
24
Table 2-1: Trophic State Model Comparison for Swan Lake South in 2011
June
July
August
October
Average
Carlson
Mesotrophic
Slightly
Eutrophic
Strongly
Mesotrophic
Mesotrophic
Strongly
Mesotrophic
Burns
Strongly
Mesotrophic
Eutrophic
Slightly
Eutrophic
Slightly
Eutrophic
Slightly
Eutrophic
Vollenweider
Hyper
Eutrophic
Hyper
Eutrophic
Hyper
Eutrophic
Strongly
Eutrophic
Slightly Hyper
Eutrophic
Larsen
Mercier
Strongly
Eutrophic
Slightly
Eutrophic
Mesotrophic
Eutrophic
Slightly
Eutrophic
Average
Eutrophic
Eutrophic
Slightly
Eutrophic
Slightly
Eutrophic
Eutrophic
The south side of Swan Lake is classified as eutrophic for 2011. This is a slightly higher
classification than that of the north side of Swan Lake, which was classified as slightly eutrophic.
This makes sense because of the fact that the inlet to Swan Lake is closer to the south side of
Swan Lake, where the inlet phosphorus concentrations were relatively high.
2.3
Swan Lake North
In 2011 water samples were collected from the north side of Swan Lake during the months
of June, July, August and October. Trophic State analysis has been performed on the north side
of Swan Lake for the following years: 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
and 2011. The Inlet of Swan Lake was sampled in 1995, 1996, 1997, 2002, 2003, 2004, 2007,
2008, 2009, 2010 and 2011.
Figure 2-14 shows the Carlson Model trophic state values for the north side of Swan Lake.
The trophic state indices for each month are in the mesotrophic range but close to the eutrophic
state. This range is classified as strongly mesotrophic.
25
Figure 2-14: Carlson Trophic State Indices for Swan Lake North in 2011
The Carlson model trophic state values for the months of June, July, August and October
in 2011 were 49.2, 49.4, 46.8 and 50.2 respectively. The trophic state for the north side of Swan
Lake was strongly mesotrophic for June, July, and October. In August the trophic state was
mesotrophic.
The Burns model was also used to calculate trophic level indices. The trophic level value
for Swan Lake North side in June was 4.2, in July the trophic value was also 4.2, in August the
trophic level was 4.0 and in October the trophic level value was 4.3. These values correspond to
trophic states of slightly eutrophic, slightly eutrophic, strongly mesotrophic, and slightly
eutrophic for the months of June, July, August and October respectively. The Carlson and Burns
Model trophic values for 2011 were normalized and compared in Figure 2-15.
26
1.0
Normalized Trophic Level
0.9
0.8
Eutrophic
0.7
0.6
0.5
Mesotrophic
Carlson
0.4
Burns
0.3
0.2
Oligotrophic
0.1
0.0
May-11
June-11
July-11
August-11
September-11 October-11 November-11
Figure 2-15: Comparison of Carlson and Burns Trophic States for Swan Lake North in 2011
Both models are consistent from month to month however the Burns model reports
trophic states slightly higher than the Carlson model.
The Vollenweider and Larsen Mercier Models were also applied to the north side of
Swan Lake for the 2011 data collected. However, the results using the Vollenweider model for
the north side of Swan Lake are exactly the same as the results for the south side of Swan Lake.
This is because the inlet to the south and north side is the same. The inlet phosphorus and
hydraulic residence time is therefore the same for both side of Swan Lake. Figure 2-12,
therefore shows the Vollenweider Model trophic state values in June, July, August and October
for the north side of Swan Lake. The trophic state for October was strongly eutrophic. The
trophic states for June through August were hyper-eutrophic.
The Larsen-Mercier Model results for the north side of Swan Lake are also the same as
the south side of Swan Lake. The Larsen Mercier Model results for the north side of Swan Lake
are therefore shown in Figure 2-13. The trophic state values for June, July, August and October
are strongly eutrophic, slightly eutrophic, mesotrophic and eutrophic respectively.
Table 2-2 shows the calculated trophic states from each of the four models used to
evaluate the north side of Swan Lake. The trophic state for each month is also displayed.
27
Table 2-2: Trophic State Model Comparison for Swan Lake North in 2011
June
July
August
October
Average
Carlson
Strongly
Mesotrophic
Strongly
Mesotrophic
Mesotrophic
Strongly
Mesotrophic
Strongly
Mesotrophic
Burns
Slightly
Eutrophic
Slightly
Eutrophic
Strongly
Mesotrophic
Slightly
Eutrophic
Slightly
Eutrophic
Vollenweider
Slightly Hyper
Eutrophic
Hyper
Eutrophic
Hyper
Eutrophic
Strongly
Eutrophic
Slightly Hyper
Eutrophic
Larsen
Mercier
Strongly
Eutrophic
Slightly
Eutrophic
Mesotrophic
Eutrophic
Slightly
Eutrophic
Average
Eutrophic
Eutrophic
Slightly
Eutrophic
Slightly
Eutrophic
Slightly
Eutrophic
The north side of Swan Lake is classified as slightly eutrophic for 2011. This result was
obtained after averaging the results from the four models used to evaluate the north side of Swan
Lake.
2.4
Two Ocean Lake
Trophic State analysis has been performed on Two Ocean Lake over the following years:
1995, 1996, 1997, 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, and 2011. The Inlet
of Two Ocean Lake was sampled in 1995, 1996, 1997, 2000, 2003, 2005, 2006, 2007, 2008,
2009, 2010 and 2011. Samples were collected for Two Ocean Lake during the months of June,
July, August and October of 2011.
Figure 2-16 shows the Carlson trophic state indices in June, July, August and October of
2011.
28
Figure 2-16: Carlson Trophic State Indices for Two Ocean Lake in 2011
The Carlson Model trophic state values of Two Ocean Lake were 62.7, 43.1, 53.2, and
56.8 for the months of June, July, August and October respectively. These values correspond to
trophic states of strongly eutrophic, mesotrophic, strongly mesotrophic, and slightly eutrophic.
The Burns Model was also used to calculate trophic level indices. The trophic level
values for Two Ocean Lake were 5.6, 3.6, 4.6, and 4.9. These values correspond to trophic states
of slightly hyper-eutrophic, mesotrophic, eutrophic and eutrophic for the months of June, July,
August and October respectively. The Carlson and Burns model trophic values of Two Ocean
Lake in 2011 were normalized and compared in Figure 2-17.
29
1.1
1.0
Normalized Trophic Level
0.9
0.8
Eutrophic
0.7
0.6
0.5
Mesotrophic
Carlson
0.4
Burns
0.3
0.2
Oligotrophic
0.1
0.0
May-11
June-11
July-11
August-11
September-11
October-11
November-11
Figure 2-17: Comparison of Carlson and Burns Trophic States for Two Ocean Lake in 2011
The Carlson and Burns Models follow a very similar trend. Like Christian Pond, the
highest trophic state occurred during June. The Burns Model trophic states generally are higher
than the Carlson model trophic states in the mesotrophic to eutrophic range.
The Vollenweider and Larsen Mercier models were also used to evaluate the trophic state
of Two Ocean Lake in 2011. Inlet data were collected in the months of June and July, for which
the Vollenweider and Larsen-Mercier Models were applied. Figure 2-18 shows the results of the
Vollenweider analysis.
30
Figure 2-18: Vollenweider Model for Two Ocean Lake in 2011
The inlet phosphorus concentrations for June and July were close. The trophic state in
both June and July is strongly eutrophic using the Vollenweider Model. Figure 2-19 shows the
results of the Larsen-Mercier analysis for the months of June and July.
Figure 2-19: Larsen Mercier Model for Two Ocean Lake in 2011
31
The phosphorus retention coefficient in July was much higher than the phosphorus
retention coefficient in June. These values result in a trophic state of strongly eutrophic for the
month of June and slightly mesotrophic for the month of July using the Larsen-Mercier Model.
Table 2-3 shows the trophic states calculated with each model over the four months
sampled for Two Ocean Lake.
Table 2-3: Trophic State Model Comparison for Two Ocean Lake in 2011
June
July
August
October
Average
Carlson
Strongly
Eutrophic
Mesotrophic
Strongly
Mesotrophic
Slightly
Eutrophic
Slightly
Eutrophic
Burns
Slightly Hyper
Eutrophic
Mesotrophic
Eutrophic
Eutrophic
Eutrophic
Vollenweider
Strongly
Eutrophic
Strongly
Eutrophic
-
-
Strongly
Eutrophic
Larsen
Mercier
Strongly
Eutrophic
Slightly
Mesotrophic
-
-
Slightly
Eutrophic
Average
Strongly
Eutrophic
Strongly
Mesotrophic
Slightly
Eutrophic
Eutrophic
Eutrophic
An average of the various model trophic states yields a eutrophic classification for Two
Ocean Lake in 2011.
2.5
Christian Pond
Trophic State analysis has been performed on Christian Pond over the following years:
1995, 2005, 2006, 2007, 2008, 2009, 2010, and 2011. The Inlet of Christian Pond was sampled
in 1995, 2005, 2006, 2007, 2008, 2009, 2010, and 2011. Samples were collected for Christian
Pond during the months of June, July, August and October in 2011.
Figure 2-20 shows the trophic state indices in June, July, August and October for 2011
using the Carlson Model.
32
Figure 2-20: Carlson Trophic State Indices for Christian Pond in 2011
The trophic level values for Christian Pond were 76.3, 49.0, 51.1, and 42.6 for the months
of June, July, August and October respectively. These values correspond to tropic states of
hyper-eutrophic, mesotrophic, strongly mesotrophic and slightly mesotrophic for the months of
June, July, August, and October respectively. The trophic state in June is noticeably high due to
the high in-lake chlorophyll-a and phosphorus concentrations.
The Burns Model was also used to calculate trophic level indices for Christian Pond. The
trophic level values for Christian Pond were 6.9, 4.1, 4.4, and 3.6 for the months of June, July,
August and October respectively. These values were computed using the Burns model and
correspond to trophic states of hyper-eutrophic, slightly eutrophic, slightly eutrophic and
mesotrophic. The Carlson and Burns model trophic values for 2011 were normalized and
compared in Figure 2-21.
33
1.2
Normalized Trophic Level
1.0
Eutrophic
0.8
0.6
Mesotrophic
Carlson
0.4
Burns
0.2
Oligotrophic
0.0
May-11
June-11
July-11
August-11
September-11
October-11
November-11
Figure 2-21: Comparison of Carlson and Burns Trophic States for Christian Pond in 2011
The Burns model and Carlson model both produced a nearly equivalent trophic value for
the month of June. We see that the Burns model continues to be higher than the Carlson model
for the remaining months. The lowest trophic state occurred during October.
The Vollenweider and Larsen Mercier Models were also used to evaluate the trophic state
of Christian Pond, but only for the month of June when inlet data was sampled. Figure 2-22
shows the Vollenweider analysis results of Christian Pond during the month of June.
34
Figure 2-22: Vollenweider Model for Christian Pond in 2011
The trophic state of Christian Pond is mesotrophic for the month of June according to the
Vollenweider analysis.
Figure 2-23 shows the results of the trophic state analysis for Christian Pond using the
Larsen-Mercier Model.
Figure 2-23: Larsen Mercier Model for Christian Pond in 2011
35
Christian Pond is classified as strongly mesotrophic in the month of June according to the
Larsen-Mercier model. This is due to the low phosphorus retention coefficient. Table 2-4 shows
the various trophic states from each model and a trophic state average.
Table 2-4: Trophic State Model Comparison for Christian Pond in 2011
June
July
August
October
Average
Carlson
Hyper
Eutrophic
Mesotrophic
Strongly
Mesotrophic
Slightly
Mesotrophic
Slightly
Eutrophic
Burns
Hyper
Eutrophic
Slightly
Eutrophic
Slightly
Eutrophic
Mesotrophic
Eutrophic
Vollenweider
Mesotrophic
-
-
-
Mesotrophic
LarsenMercier
Strongly
Mesotrophic
-
-
-
Strongly
Mesotrophic
Average
Eutrophic
Strongly
Mesotrophic
Slightly
Eutrophic
Mesotrophic
Strongly
Mesotrophic
Even though there is disparity among the various models for the month of June, the
average is a good description of the water quality of Christian Pond. Christian Pond is classified
as strongly mesotrophic in 2011.
2.6
Cygnet Pond
Samples were collected for Cygnet Pond during the months of June, July and August in
2011. Trophic State analysis has been performed on Cygnet Pond over the following years:
1995, 1996, 1997, 2003, 2005, 2008, 2009, 2010, and 2011. The inlet has been sampled in 1995,
2005, and 2011.
Figure 2-24 shows the trophic state indices in June, July and August of 2011 using the
Carlson Model.
36
Figure 2-24: Carlson Trophic State Indices for Cygnet Pond in 2011
Trophic state indices in the mesotrophic range were calculated using the Carlson Model
as shown Figure 2-24 above. The chlorophyll-a concentrations were relatively low for Cygnet
Pond. The trophic state values for Cygnet Pond were 44.3, 46.3, and 50.2 for the months of
June, July and August respectively. These values correspond to trophic state classifications of
mesotrophic in June and July, and strongly mesotrophic in August.
The Burns model was also used to calculate trophic level indices. The trophic level
values for Cygnet Pond using the Burns model were 3.6, 3.9, and 4.3 for the months of June, July
and August respectively. The trophic levels for Cygnet Pond which correspond to these values
are mesotrophic, strongly mesotrophic, and slightly eutrophic for the months of June, July and
August respectively. The Carlson and Burns Model trophic values for 2011 were normalized
and compared in Figure 2-25.
37
1.0
0.9
Eutrophic
Normalized Trophic Level
0.8
0.7
0.6
0.5
Mesotrophic
Carlson
Burns
0.4
0.3
Oligotrophic
0.2
0.1
0.0
May-11
June-11
July-11
August-11
September-11
Figure 2-25: Comparison of Carlson and Burns Trophic States for Cygnet Pond in 2011
Both the Carlson and Burns Models are consistent in that both show an increase in
trophic state over the months of June to August. The trophic states calculated with the Burns
model are higher than the trophic states calculated using the Carlson model for this mesotrophic
range. Both models calculate trophic states in the mesotrophic to eutrophic range.
The Vollenweider and Larsen Mercier Models were used to evaluate the trophic state of
Cygnet Pond only during the month of June. This is the month in which inlet phosphorus
concentration data were collected. Figure 2-26 shows the trophic state result in June using the
Vollenweider Model.
38
Figure 2-26: Vollenweider Model for Cygnet Pond in 2011
A strongly mesotrophic trophic state was determined for Cygnet Pond using the
Vollenweider Model. This compares well to the mesotrophic trophic state calculated with the
Carlson and Burns Models. The in-lake phosphorus concentration was twice as large as the inlet
phosphorus concentration for the month of June.
Figure 2-27 shows the trophic state result calculated with the Larsen-Mercier Model for
the month of June.
39
Mean Inflowing Phosphorus Conc. (mg/l)
1
0.1
Eutrophic Zone
0.0, 0.03
Mesotrophic Zone
0.01
Oligotrophic Zone
0.001
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Phosphorus Retention Coefficient
0.8
0.9
1.0
June
Figure 2-27: Larsen Mercier Model for Cygnet Pond in 2011
The phosphorus retention coefficient is zero for Cygnet Pond because the in-lake
phosphorus concentration was higher than the inlet phosphorus concentration. The inlet
phosphorus concentration of Cygnet Pond was 0.03 mg/L resulting in a trophic state of slightly
eutrophic for 2011 using the Larsen-Mercier Model.
Table 2-5 shows the trophic states calculated from each of the four models used to
evaluate Cygnet Pond. The trophic state for each month is also displayed.
Table 2-5: Trophic State Model Comparison for Cygnet Pond in 2011
June
July
August
Average
Carlson
Mesotrophic
Mesotrophic
Strongly
Mesotrophic
Mesotrophic
Burns
Mesotrophic
Strongly
Mesotrophic
Slightly
Eutrophic
Strongly
Mesotrophic
Vollenwieder
Strongly
Mesotrophic
-
-
Strongly
Mesotrophic
Larsen
Mercier
Slightly
Eutrophic
-
-
Slightly
Eutrophic
Average
Strongly
Mesotrophic
Strongly
Mesotrophic
Strongly
Mesotrophic
Strongly
Mesotrophic
40
An average of the various model trophic states yields a strongly mesotrophic classification
for Cygnet Pond in 2011.
2.7
Emma Matilda Lake West
Trophic State analysis has been performed on Emma Matilda Lake over the following years:
1995, 2005, 2008, 2009, 2010, and 2011. The Inlet of Emma Matilda Lake was sampled in
1995, 2005, 2009, 2010 and 2011. Samples were collected for Emma Matilda Lake during the
months of June, August and October.
Figure 2-28 shows the trophic state indices in June, August and October of 2011 for the
Carlson Model.
Figure 2-28: Carlson Trophic State Indices for Emma Matilda Lake in 2011
The trophic state values for Emma Matilda Lake were 44.4, 38.7, and 40.7 during the
months of June, August and October respectively. These values were calculated using the
Carlson Model. The trophic state values correspond to trophic state classifications of
mesotrophic, slightly mesotrophic and slightly mesotrophic for the months of June, August and
October respectively.
41
The Burns Model was also used to calculate trophic level indices for Emma Matilda
Lake. The trophic level values for Emma Matilda Lake were 3.8, 3.2, and 3.3 for the months of
June, August and October respectively. These values correspond to trophic states of strongly
mesotrophic, slightly mesotrophic, and mesotrophic for the months of June, August and October
respectively. The Carlson and Burns model trophic values for 2011 were normalized and
compared in Figure 2-29.
0.9
Eutrophic
0.8
Normalized Trophic Level
0.7
0.6
Mesotrophic
0.5
0.4
Carlson
0.3
Burns
Oligotrophic
0.2
0.1
0.0
May-11
June-11
July-11
August-11
September-11
October-11
November-11
Figure 2-29: Comparison of Carlson and Burns Trophic States for Emma Matilda Lake in 2011
Figure 2-29 shows that the difference in trophic states was largest during June. The two
models follow the same overall trend, with the Burns Model trophic states being higher than
those calculated with the Carlson Model. The lowest trophic state is calculated during August.
The Vollenweider and Larsen Mercier Models were also used to evaluate the trophic state
of Emma Matilda Lake. The inlet phosphorus concentration was only collected in the month of
June however, and therefore the Vollenweider and Larsen-Mercier Models were only applied
during June. Figure 2-30 is a graphical representation of the Vollenweider trophic state analysis
for Emma Matilda Lake.
42
Figure 2-30: Vollenweider Model for Emma Matilda Lake in 2011
The Vollenweider model produces a mesotrophic classification for the month of June.
Figure 2-31 shows the results for the Larsen-Mercier analysis of Emma Matilda Lake for
the month of June.
Figure 2-31: Larsen Mercier Model for Emma Matilda Lake in 2011
43
The Larsen-Mercier model produces a slightly eutrophic classification for Emma Matilda
Lake in the month of June. The trophic states calculated from the four models of Emma Matilda
Lake in the month of June all produced similar results. This can be seen in Table 2-6 and shows
the consistency of the four models for the month of June.
Table 2-6: Trophic State Model Comparison for Emma Matilda Lake in 2011
June
August
October
Average
Carlson
Mesotrophic
Slightly
Mesotrophic
Slightly
Mesotrophic
Slightly
Mesotrophic
Burns
Strongly
Mesotrophic
Slightly
Mesotrophic
Mesotrophic
Mesotrophic
Vollenweider
Mesotrophic
-
-
Mesotrophic
Larsen
Mercier
Slightly
Eutrophic
-
-
Slightly
Eutrophic
Average
Strongly
Mesotrophic
Slightly
Mesotrophic
Slightly
Mesotrophic
Mesotrophic
And average of all models yields a trophic state classification of mesotrophic for Emma
Matilda Lake in 2011.
2.8
Oxbow Bend
Samples were collected from Oxbow Bend during the month of October. Trophic State
analysis has been performed on Oxbow Bend over the following years: 1995, 2008, 2010, and
2011. Figure 2-32 shows the trophic state indices in October of 2011 using the Carlson model.
44
Figure 2-32: Carlson Trophic State Indices for Oxbow Bend in 2011
The trophic state value for Oxbow Bend in October was 40.7, which corresponds to a
slightly mesotrophic classification.
The Burns Model was also used to calculate a trophic level index for Oxbow Bend. The
trophic level value for Oxbow Bend in October was 3.3 using the Burns Model. This value
corresponds to a mesotrophic classification. The Carlson and Burns Model trophic values for
2011 were normalized and are compared in Figure 2-33.
45
Figure 2-33: Comparison of Carlson and Burns Trophic States for Oxbow Bend in 2011
The Burns Model produced a slightly higher trophic state classification since the trophic
state was in the mesotrophic range.
The Vollenweider and Larsen Mercier Models were not used for Oxbow Bend because is
part of a river and is itself an inlet. The Carlson and Burns Models were therefore the only
models used to determine the trophic state of Oxbow Bend in 2011. Table 2-7 shows the trophic
states calculated from the Carlson and Burns Models for October and an average of the two.
Table 2-7: Trophic State Model Comparison for Oxbow Bend in 2011
October
Carlson
Slightly
Mesotrophic
Burns
Mesotrophic
Average
Slightly
Mesotrophic
An average of the Carlson and Burns model trophic states yields a slightly mesotrophic
classification for Oxbow Bend in 2011.
46
2.9
Taggart Lake
Trophic state analysis has been performed on Taggart Lake during the following years:
1995, 2005, 2008, 2009, 2010, and 2011. The inlet was sampled in 1995 and 2005. In-lake
samples for 2011 were collected during the months of June and October.
Figure 2-34 displays the calculated Trophic State Indices for Taggart Lake using the
Carlson Model based on 2011 data.
Figure 2-34: Carlson Trophic State Indices for Taggart Lake in 2011
The trophic state value in June was 36.7 and in October the trophic state value was 42.0.
These values were both calculated using the Carlson Model. The Carlson trophic state indices
show that Taggart Lake has a slightly oligotrophic state in June and a slightly mesotrophic state
in October.
The Burns Model was also used to calculate trophic level indices. The trophic level value
for Taggart Lake in June was 3.0, and in October the trophic level value was 3.6. These values
correspond to trophic state classifications of slightly mesotrophic and mesotrophic. The Carlson
and Burns Model trophic values for 2011 were normalized and compared in Figure 2-35.
47
0.9
Eutrophic
0.8
Normalized Trophic Level
0.7
0.6
Mesotrophic
0.5
0.4
Carlson
0.3
Burns
Oligotrophic
0.2
0.1
0.0
May-11
June-11
July-11
August-11
September-11
October-11
November-11
Figure 2-35: Comparison of Carlson and Burns Trophic States for Taggart Lake in 2011
The Carlson Model and Burns Model both show an increasing trophic state from June to
October. The Carlson and Burns Models give nearly identical trophic state values.
The Vollenweider and Larsen-Mercier Models were not used to determine a trophic state
for Taggart Lake because no inlet samples were collected for Taggart Lake in 2011. Table 2-8
shows the trophic states calculated from each model for June and October.
Table 2-8: Trophic State Model Comparison for Taggart Lake in 2011
June
October
Average
Carlson
Slightly
Oligotrophic
Slightly
Mesotrophic
Slightly
Oligotrophic
Burns
Slightly
Mesotrophic
Mesotrophic
Slightly
Mesotrophic
Average
Slightly
Oligotrophic
Mesotrophic
Slightly
Mesotrophic
An average of the two months and two models produce a slightly mesotrophic state for
Taggart Lake in 2011.
48
2.10 Moose Pond
Trophic State analysis has been performed on Moose Pond over the following years:
2002, 2008, 2009, 2010, and 2011. The Inlet of Moose Pond was sampled in 2008, 2009, 2010
and 2011. In-lake samples were collected for Moose Pond during the months of June and
October of 2011.
Figure 2-36 shows the trophic state indices in June and October of 2011, using the Carlson
Model.
Figure 2-36: Carlson Trophic State Indices for Moose Pond in 2011
The Carlson trophic state values for Moose Pond were 44.4 and 42.0 for the months of
June and October respectively. These values correspond to mesotrophic and slightly
mesotrophic classifications for June and October respectively.
The Burns Model was also used to calculate trophic level indices. The trophic level
values for Moose Pond were 3.7 and 3.5 during the months of June and October respectively.
These values correspond to trophic states of strongly mesotrophic and mesotrophic during the
months of June and October respectively. The Carlson and Burns Model trophic values for 2011
were normalized and compared in Figure 2-37.
49
0.9
Eutrophic
0.8
Normalized Trophic Level
0.7
0.6
Mesotrophic
0.5
0.4
Carlson
0.3
0.2
Burns
Oligotrophic
0.1
0.0
May-11
June-11
July-11
August-11
September-11
October-11
November-11
Figure 2-37: Comparison of Carlson and Burns Trophic States for Moose Pond in 2011
The Burns Model produces consistently higher trophic states over the months of June and
October. The trophic state trend from June to October is slightly downward.
The Vollenweider and Larsen-Mercier models were also used to evaluate the trophic state
of Moose Pond in June and October of 2011. Figure 2-38 is a graphical display of the trophic
state results for Moose Pond using the Vollenweider Model.
50
Figure 2-38: Vollenweider Model for Moose Pond in 2011
The flow coming into Moose Pond had a low phosphorus concentration of less than 10
ppb in June and October. This produced a slightly oligotrophic classification for Moose Pond
during both June and October.
Figure 2-39 displays the results of the trophic state analysis for Moose Pond using the
Larsen-Mercier Model.
Figure 2-39: Larsen Mercier Model for Moose Pond in 2011
51
The phosphorus retention coefficients were zero for Moose Pond which resulted in a
slightly oligotrophic classification for June and October using the Larsen Mercier Model.
Table 2-9 shows the trophic states calculated with each model, as well as the trophic state
average of all models used for Moose Pond.
Table 2-9: Trophic State Model Comparison for Moose Pond in 2011
June
October
Average
Carlson
Mesotrophic
Slightly
Mesotrophic
Mesotrophic
Burns
Strongly
Mesotrophic
Mesotrophic
Mesotrophic
Vollenweider
Slightly
Oligotrophic
Slightly
Oligotrophic
Slightly
Oligotrophic
Larsen
Mercier
Slightly
Oligotrophic
Slightly
Oligotrophic
Slightly
Oligotrophic
Average
Mesotrophic
Slightly
Oligotrophic
Slightly
Mesotrophic
An average of the various model trophic state values yields a slightly mesotrophic
classification for Moose Pond in 2011.
2.11 String Lake
Trophic State analysis has been performed on String Lake over the following years: 1995,
2005, 2009, 2010, and 2011. The Inlet of String Lake was sampled in 2009, 2010 and 2011.
Inlet and in-lake samples were collected for String Lake during June of 2011.
Figure 2-40 shows the String Lake Carlson trophic state indices for June of 2011.
52
Figure 2-40: Carlson Trophic State Indices for String Lake in 2011
The trophic state value for String Lake in June was 37.3 which corresponds to a trophic
state of slightly oligotrophic.
The Burns Model was also used to calculate the trophic level index for String Lake. The
trophic level value for String Lake in June was 3.1 which corresponds to a trophic level of
slightly mesotrophic. The Carlson and Burns Model trophic values for 2011 were normalized
and compared in the Figure 2-41.
53
Figure 2-41: Comparison of Carlson and Burns Trophic States for String Lake in 2011
The Burns Model once again produces a trophic state which is higher than the trophic
state calculated by the Carlson Model in the slightly mesotrophic range.
The Vollenweider and Larsen Mercier Models were also used to evaluate the trophic state
of String Lake in 2011. Figure 2-42 shows the results of the Vollenweider analysis during June.
Figure 2-42: Vollenweider Model for String Lake in 2011
54
The Vollenweider analysis gives String Lake a classification of slightly oligotrophic for
the month of June. Figure 2-43 shows the results of the Larsen-Mercier model for String Lake
during the month of June.
Figure 2-43: Larsen Mercier Model for String Lake in 2011
Like the Vollenweider Model the Larsen-Mercier Model also gives String Lake a
classification of slightly oligotrophic for the month of June.
Table 2-10 shows the trophic states calculated with each of the four models for the month
of June, as well as an average.
55
Table 2-10: Trophic State Model Comparison for String Lake in 2011
June
Carlson
Slightly
Oligotrophic
Burns
Slightly
Mesotrophic
Vollenweider
Slightly
Oligotrophic
Larsen
Mercier
Slightly
Oligotrophic
Average
Slightly
Oligotrophic
An average of all models yields a slightly oligotrophic classification for String Lake in 2011.
2.12 Bradley Lake
Samples were collected for Bradley Lake during the months of June and October of 2011.
Trophic State analysis has been performed on Bradley Lake over the following years: 1995,
2005, 2008, 2009, 2010, and 2011. The Inlet of Bradley Lake was sampled in 1995 and 2005.
Figure 2-44 shows the Carlson trophic state indices during June and October of 2011 for
Bradley Lake.
56
Figure 2-44: Carlson Trophic State Indices for Bradley Lake in 2011
The trophic state of Bradley Lake was Oligotrophic during June and Slightly
Oligotrophic during October. The trophic state values were 32.7 in June and 37.6 in October.
The Burns Model was also used to calculate trophic level indices for Bradley Lake. The
trophic level value for Bradley Lake in June was 2.6, and in October the trophic level value was
3.1. The trophic state in June is classified as oligotrophic and the trophic state in October is
classified as slightly mesotrophic. The Carlson and Burns Model trophic values for 2011 were
normalized and compared in Figure 2-45.
57
0.9
Eutrophic
Normalized Trophic Level
0.8
0.7
Carlson
0.6
Burns
Mesotrophic
0.5
0.4
0.3
Oligotrophic
0.2
0.1
May-11
June-11
July-11
August-11
September-11
October-11
November-11
Figure 2-45: Comparison of Carlson and Burns Trophic States for Bradley Lake in 2011
Figure 2-45 shows that both models produce an increase in trophic state values from June
to October. The normalized trophic levels are used to compare the trophic states calculated from
the Carlson and Burns Models.
The Vollenweider and Larsen Mercier Models were not used to calculate the total trophic
state of Bradley Lake because no inlet samples were collected in 2011. The Carlson and Burns
Models were therefore the only models used to determine the trophic state of Bradley Lake in
2011. Table 2-11 shows the trophic states calculated from the Carlson and Burns Models for
June and October and their corresponding averages.
Table 2-11: Trophic State Model Comparison for Bradley Lake in 2011
June
October
Average
Carlson
Oligotrophic
Slightly
Oligotrophic
Slightly
Oligotrophic
Burns
Oligotrophic
Slightly
Mesotrophic
Slightly
Oligotrophic
Average
Oligotrophic
Slightly
Mesotrophic
Slightly
Oligotrophic
An average of the Carlson and Burns trophic states yields a slightly oligotrophic
classification for Bradley Lake in 2011.
58
2.13 Phelps Lake West
Samples were collected for Phelps Lake during the months of June and August in 2011.
Trophic State analysis has been performed on Phelps Lake over the following years: 1995, 2003,
2005, 2008, 2009, and 2011. The Inlet of Phelps Lake was sampled in 1995, 1996, 2003, 2005,
and 2011. Figure 2-46 shows the Carlson Model trophic state indices in June and August of
2011.
Figure 2-46: Carlson Trophic State Indices for Phelps Lake in 2011
The trophic state value for Phelps Lake in June was 31.0, and in August the trophic state
value was 36.7. The trophic state in June is classified as oligotrophic and in October the trophic
state classified as slightly oligotrophic.
The Burns Model was also used to calculate trophic level indices. The trophic level value
for Phelps Lake in June was 2.4, and in August the trophic level value was 3.0. These values
were both calculated using the Burns Model and correspond to oligotrophic and slightly
mesotrophic classifications for June and August respectively. The Carlson and Burns Model
trophic values for 2011 were normalized and compared in Figure 2-47.
59
0.7
Normalized Trophic Level
0.6
Mesotrophic
0.5
0.4
Carlson
Burns
0.3
Oligotrophic
0.2
0.1
May-11
June-11
July-11
August-11
September-11
Figure 2-47: Comparison of Carlson and Burns Trophic States for Phelps Lake in 2011
The trophic state classification for Phelps Lake in June was oligotrophic using both the
Carlson and Burns Models. The two models diverge as the trophic state values increase. The
Burns Model produces a higher trophic state than the Carlson model does for the month of
August. Both models however, have an upward trend.
The Vollenweider and Larsen Mercier Models were also used to evaluate the trophic state
of Phelps Lake in 2011. Figure 2-48 is a Vollenweider graph with the trophic state results for
Phelps Lake in June and August.
60
Figure 2-48: Vollenweider Model for Phelps Lake in 2011
The inflow phosphorus concentrations into Phelps Lake were 10 mg/L for June and
August. Phelps Lake is a large lake and the hydraulic residence time of Phelps Lake is therefore
relatively large. These two parameters resulted in a strongly oligotrophic classification of Phelps
Lake for June and August using the Vollenweider Model.
Figure 2-49 shows the trophic state results of Phelps Lake using the Larsen-Mercier
method.
61
Figure 2-49: Larsen Mercier Model for Phelps Lake in 2011
There was no measureable retention of phosphorus in Phelps Lake from the inlet. This
resulted in a slightly oligotrophic classification for Phelps Lake using the Larsen-Mercier Model.
Table 2-12 shows the trophic states which were calculated for every model during June
and October of 2011.
Table 2-12: Trophic State Model Comparison for Phelps Lake in 2011
June
August
Average
Carlson
Oligotrophic
Slightly
Oligotrophic
Slightly
Oligotrophic
Burns
Oligotrophic
Slightly
Mesotrophic
Slightly
Oligotrophic
Vollenweider
Strongly
Oligotrophic
Strongly
Oligotrophic
Strongly
Oligotrophic
Larsen Mercier
Slightly
Oligotrophic
Slightly
Oligotrophic
Slightly
Oligotrophic
Average
Oligotrophic
Slightly
Oligotrophic
Oligotrophic
62
It was determined from the average of all four models that Phelps Lake is classified as
oligotrophic for 2011.
2.14 Arrowhead Pond
Table 2-13: Overview of Arrowhead Pond
Arrowhead Pond
Carlson, Burns, and
Larsen-Mercier
Not Applicable
1
Oligotrophic
Not Applicable
9,170 ft.
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Samples were collected for Arrowhead Pond during August of 2011. Trophic State
analysis has been performed on Arrowhead Pond only in 2011.
Figure 2-50 shows the trophic state indices in August of 2011, which were calculated with
the Carlson Model.
Figure 2-50: Carlson Trophic State Indices for Arrowhead Pond in 2011
63
The trophic level value for Arrowhead Pond in August was 32, which corresponds to an
oligotrophic classification.
The Burns Model was also used to calculate trophic level indices for Arrowhead Pond.
The Burns Model trophic level value for Arrowhead Pond was 2.7 in August. This corresponds
to an oligotrophic classification. The Carlson and Burns Model trophic values for 2011 were
normalized and compared in Figure 2-51.
Figure 2-51: Comparison of Carlson and Burns Trophic States for Arrowhead Pond in 2011
The Burns Model trophic state for Arrowhead Pond was lower than the Carlson trophic
state.
The Vollenweider and Larsen Mercier Models were also used to evaluate the trophic state
of Arrowhead Pond in 2011. Figure 2-52 is a Vollenweider graph with the trophic state result for
Arrowhead Pond in August.
64
Figure 2-52: Vollenweider Model for Arrowhead Pond in 2011
The Vollenweider model produced a slightly oligotrophic trophic state of for Arrowhead
Pond in 2011.
Figure 2-53 shows the trophic state results for Arrowhead Pond using the Larsen-Mercier
Model and graph.
65
Figure 2-53: Larsen Mercier Model for Arrowhead Pond in 2011
This is another body of water in which the lowest possible chlorophyll-a, and phosphorus
concentrations were measured. There is no measureable phosphorus retention from the inlet.
Arrowhead Pond is classified as slightly oligotrophic according to the Larsen-Mercier Model for
August, 2011.
Table 2-14 shows the trophic state classifications of each model used to evaluate
Arrowhead Pond.
Table 2-14: Trophic State Model Comparison for Arrowhead Pond in 2011
August
Carlson
Oligotrophic
Burns
Oligotrophic
Vollenweider
Slightly
Oligotrophic
Larsen Mercier
Slightly
Oligotrophic
Average
Oligotrophic
66
Arrowhead pond is classified as oligotrophic using the four models above with the 2011
data.
2.15 Ramshead Lake
Table 2-15: Overview of Ramshead Lake
Ramshead Lake
Carlson, Burns, and
Larsen-Mercier
Not Applicable
1
Oligotrophic
Not Applicable
9,524 ft.
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Samples were collected from Ramshead Lake during the month of August in 2011. Both
in-lake and inlet data were collected. Figure 2-54 shows the trophic state indices in August of
2011 using the Carlson Model.
Figure 2-54: Carlson Trophic State Indices for Ramshead Lake in 2011
67
An oligotrophic trophic state was calculated for Ramshead Lake using the Carlson
Model. The trophic state value for Ramshead Lake in August was 32.
The Burns Model was also used to calculate a trophic level index. Using the Burns
Model, the trophic level value for Ramshead Lake in August is 2.6. This value also corresponds
to a trophic state of oligotrophic. The Carlson and Burns Model trophic values for 2011 were
normalized and compared in Figure 2-55.
Figure 2-55: Comparison of Carlson and Burns Trophic States for Ramshead Lake in 2011
Figure 2-55 shows that the Burns Model reported a trophic value which was less than the
trophic value calculated with the Carlson Model. The two values are very close however.
The Vollenweider and Larsen Mercier Models were also used to evaluate the trophic state
of Ramshead Lake in 2011. Figure 2-56 is the Vollenweider graph with the trophic state results
for Ramshead in August, 2011.
68
Figure 2-56: Vollenweider Model for Ramshead Lake in 2011
The Vollenweider Model produced a slightly oligotrophic trophic state of for Ramshead
Lake.
Figure 2-57 shows the trophic state result for Ramshead Lake in the month of August
using the Larsen-Mercier Model.
69
Figure 2-57: Larsen Mercier Model for Ramshead Lake in 2011
The lowest possible inlet phosphorus concentration of 10 mg/L was reported for
Ramshead Lake. No phosphorus is measurably retained by Ramshead Lake and so the PRC is
zero. This classifies Ramshead Lake as slightly oligotrophic according to the Larsen Mercier
Model.
Table 2-16 shows the trophic states of Ramshead Lake for each of the three models used
to evaluate Ramshead Lake.
Table 2-16: Trophic State Model Comparison for Ramshead Lake in 2011
August
Carlson
Oligotrophic
Burns
Oligotrophic
Vollenweider
Slightly
Oligotrophic
Larsen Mercier
Slightly
Oligotrophic
Average
Oligotrophic
70
The average trophic state of Ramshead Lake is oligotrophic for the 2011 data samples.
2.16 Lake of the Crags
One sample was collected for Lake of the Crags during August of 2011. Trophic State
analysis has been performed on Lake of the Crags in 1995, and 2011. Figure 2-58 shows the
trophic state index for August of 2011 using the Carlson model.
Figure 2-58: Carlson Trophic State Indices for Lake of the Crags in 2011
The Carlson trophic state value for Lake of the Crags in August was 32 which is an
oligotrophic trophic state.
The Burns Model was also used to calculate a trophic level index for the month of
August. The trophic level value for Lake of the Crags in August was 2.5, which corresponds to
an oligotrophic trophic state. The Carlson and Burns Model trophic values for 2011 were
normalized and compared in Figure 2-59.
71
Figure 2-59: Comparison of Carlson and Burns Trophic States for Lake of the Crags in 2011
The Burns Model trophic state value was slightly lower than the Carlson Model trophic
state value. However, the two trophic state values are very close and both yield an oligotrophic
classification.
The Vollenweider and Larsen Mercier Models were also used to evaluate the trophic state
of Lake of the Crags in 2011. Figure 2-36 is the Vollenweider graph with the trophic state
results for Lake of the Crags in August, 2011.
72
Figure 2-60: Vollenweider Model for Lake of the Crags in 2011
The Vollenweider Model produced a slightly oligotrophic trophic state of for Ramshead
Lake.
The Larsen-Mercier Model graph for Lake of the Crags in August, 2011 is shown in
Figure 2-60.
73
Figure 2-61: Larsen Mercier Model for Lake of the Crags in 2011
A slightly oligotrophic state was calculated for Lake of the Crags with the LarsenMercier Model. The lab only reports phosphorus concentration values as low as 10 mg/L, so it is
likely that Lake of Crags is oligotrophic according to the Larsen Mercier Model.
Table 2-17 shows the trophic states of Lake of the Crags for each of the three models
used to evaluate Lake of the Crags.
Table 2-17: Trophic State Model Comparison for Lake of the Crags in 2011
August
Carlson
Oligotrophic
Burns
Oligotrophic
Vollenweider
Slightly
Oligotrophic
Larsen Mercier
Slightly
Oligotrophic
Average
Oligotrophic
74
An average of the three models used to evaluate Lake of the Crags yields an oligotrophic
classification for the 2011 data.
75
76
3
TEMPORAL COMPARISON OF SELECTED LAKES AND PONDS IN GRAND
TETON NATIONAL PARK
Dr. Woodruff Miller of Brigham Young University and his students have been collecting
and analyzing water quality data in Grand Teton National Park since 1995. New samples are
collected every year to add to the historical data. These data are then analyzed to determine if
the eutrophication process of a particular body of water is progressing or slowing.
There are several data series plotted for each lake. The Carlson trophic state values are
organized into the months in which the various samples were taken. This is done to observe
monthly trends in the Carlson trophic states. Carlson trophic states for every month are also
plotted together on a single graph to determine an overall trend. The inlet phosphorus
concentrations for all years are also plotted together on a single graph. Lastly, the phosphorus
and chlorophyll-a concentrations are plotted on the same graph to make comparisons.
3.1
Swan Lake South
Table 3-1: Overview of Swan Lake South
Swan Lake South
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Carlson, Burns, Vollenweider
and Larsen Mercier
Slightly Decreasing
13
Eutrophic
Increasing
6,796 ft
Trophic State analysis has been performed on the south side of Swan Lake over the
following years: 1995, 1996, 1997, 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, and
2011. Figures 3-1 through 3-4 show the Carlson trophic state trends for June, July, August and
October during years from 1995 to 2011. Figure 3-5 is a plot of all available Carlson Model data
with respect to time.
77
June
60.0
50.0
TSI
40.0
y = 0.1569x - 265.88
R² = 0.086
30.0
20.0
10.0
0.0
1990
1995
2000
2005
2010
2015
Year
Figure 3-1: Total TSI Trend for Swan Lake South in the Month of June
July
60.0
50.0
TSI
40.0
y = -0.035x + 119.12
R² = 0.0024
30.0
20.0
10.0
0.0
1994
1996
1998
2000
2002
2004
2006
2008
2010
Year
Figure 3-2: Total TSI Trend for Swan Lake South in the Month of July
78
2012
August
60.0
50.0
TSI
40.0
y = -0.4485x + 946.09
R² = 0.3526
30.0
20.0
10.0
0.0
1990
1995
2000
2005
2010
2015
Year
Figure 3-3: Total TSI Trend for Swan Lake South in the Month of August
TSI
October
52.0
51.0
50.0
49.0
48.0
47.0
46.0
45.0
44.0
43.0
42.0
1990
y = 0.0146x + 19.503
R² = 0.0011
1995
2000
2005
2010
2015
Year
Figure 3-4: Total TSI Trend for Swan Lake South in the Month of October
The coefficient of determination ( ) values for the south side of Swan Lake are much
less statistically significant than the coefficients of determination for the north side of Swan
Lake. This will be seen in the section 3.2 of this report. The Carlson trophic state indices have
an increasing trend for the months of June and October. The trends of the July and August plots
are decreasing. The slopes of the trend lines for July and October however, are nearly flat at
zero. It appears as though the south side of Swan Lake is more susceptible to the increasing inlet
79
phosphorus trend. This is to be expected as the Swan Lake inlet is located closer to the south
end.
All Data
Eutrophic
60.0
50.0
Mesotrophic
40.0
30.0
20.0
1994
y = -0.1138x + 276.36
R² = 0.0316
1998
Oligotrophic
2002
2006
2010
2014
Year
Figure 3-5: Total TSI Trend for Swan Lake South for all Available Data
Figure 3-5 shows that all available data for the south side of Swan Lake give a slight
decreasing trend in the Carlson trophic state indices. The coefficient of determination is not
significant however and the trend is decreasing very slightly.
Figure 3-6 shows the trend in inlet phosphorus concentration for Swan Lake. This plot is
the same as the inlet plot for Swan Lake North since there is one inlet into Swan Lake.
Inlet
Total Phosphorus (ppb)
350
300
250
y = 7.2229x - 14366
R² = 0.356
200
150
100
50
0
1990
1995
2000
2005
2010
2015
Year
Figure 3-6: Total Inlet Phosphorus Concentrations for Swan Lake South
80
The coefficient of determination for the inlet phosphorus data is moderately significant
with a steep increasing trend. All monthly trends of the north side of Swan Lake show a
decreasing trend, while some of the monthly trends of the south side of Swan Lake show an
increasing trend. This further proves that the south side of Swan Lake seems to be more
susceptible to the increasing inlet phosphorus concentration trends.
Figure 3-7 shows the in-lake phosphorus and chlorophyll-a concentration trends for the
south side of Swan Lake.
Inlake
140
120
100
y = -0.8496x + 1733.9
R² = 0.0563
80
60
y = 0.0297x - 55.098
R² = 0.0044
40
20
0
1990
1995
2000
2005
2010
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
2015
Figure 3-7: Phosphorus and Chlorophyll-a Concentrations for Swan Lake South
The trend of the in-lake phosphorus concentration for the south side of Swan Lake has a
slight decreasing trend. However, when only considering the years after the year 2000, the inlake phosphorus concentration seems to be fairly constant with a variation of about 20 ppb. The
chlorophyll-a concentration has a nearly flat trend line. The trends of these two parameters are
consistent with the monthly Carlson trophic state trends for the south side of Swan Lake. From
Figures 3-5 and 3-7 it appears that the water quality of the south side of Swan Lake is improving
slightly.
81
3.2
Swan Lake North
Table 3-2: Overview of Swan Lake North
Swan Lake North
Carlson, Burns, Vollenweider
and Larsen Mercier
Decreasing
10
Slightly Eutrophic
Increasing
6,796 ft.
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Trophic State analysis has been performed on the north side Swan Lake over the following
years: 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, and 2011. Figures 3-8 through
3-11 show the Carlson trophic state trends for specific months during years from 2002 to 2011.
Figure 3-12 is a plot of all available data from the Carlson Model with respect to time.
June
60.0
50.0
TSI
40.0
y = -0.8385x + 1733.9
R² = 0.4634
30.0
20.0
10.0
0.0
2002
2004
2006
2008
2010
Year
Figure 3-8: Total TSI Trend for Swan Lake North in the Month of June
82
2012
July
60.0
50.0
TSI
40.0
y = -1.1113x + 2279.8
R² = 0.5224
30.0
20.0
10.0
0.0
2000
2002
2004
2006
2008
2010
2012
Year
Figure 3-9: Total TSI Trend for Swan Lake North in the Month of July
August
70.0
y = -1.993x + 4049.7
R² = 0.6587
60.0
50.0
TSI
40.0
30.0
20.0
10.0
0.0
2000
2002
2004
2006
2008
2010
Year
Figure 3-10: Total TSI Trend for Swan Lake North in the Month of August
83
2012
TSI
October
54.0
53.0
52.0
51.0
50.0
49.0
48.0
47.0
46.0
45.0
44.0
2000
y = -0.3118x + 676.43
R² = 0.1244
2002
2004
2006
2008
2010
2012
Year
Figure 3-11: Total TSI Trend for Swan Lake North in the Month of October
There are notable trends in the Carlson trophic states for each of the four monthly plots.
The plots of the Carlson trophic states, for each month, show a decreasing trend. The June, July
and August plots each have a significant amount of data with statistically significant coefficients
of determination. The trophic states for the months of June, July and August were higher in 2011
than they were in 2010. The overall trends however, remain decreasing. Considering these
observations it appears that the total trophic state of the north side of Swan Lake is decreasing.
This is associated with an improvement in the water quality of the north side of Swan Lake.
All Data
70.0
Eutrophic
60.0
TSI
50.0
Mesotrophic
40.0
y = -1.303x + 2666.3
R² = 0.5234
30.0
20.0
2002
2004
2006
2008
Oligotrophic
2010
2012
Year
Figure 3-12: Total TSI Trend for Swan Lake North for all Available Data
84
2014
A decreasing trend is clearly seen when all available data from the north side of Swan
Lake are plotted. A coefficient of determination of 0.52 is significant, and the trend from 2002
to present remains decreasing. There was a slight rise in the trophic state indices from 2010 to
2011 for Swan Lake North. When taking the trophic state indices from all sampled years into
account however, the trend remains downward. Figure 3-13 shows the inlet phosphorus
concentrations for Swan Lake.
Inlet
Total Phosphorus (ppb)
350
300
250
200
150
y = 7.2229x - 14366
R² = 0.356
100
50
0
1990
1995
2000
2005
2010
2015
Year
Figure 3-13: Total Inlet Phosphorus Concentrations for Swan Lake North
It is interesting to note that the inlet phosphorus concentrations of Swan Lake are
increasing. The inlet phosphorus concentration data after the year 2000 do not seem to be
increasing quite as much when neglecting the data from prior years. The increasing inlet
phosphorus concentration data do not seem to have a strong effect on the in-lake trophic state
trends for Swan Lake North however.
Figure 3-14 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
of Swan Lake North.
85
140
40
120
35
100
30
y = -4.7182x + 9509
R² = 0.354
80
y = -1.2726x + 2561
R² = 0.3451
60
25
20
15
40
10
20
5
Total Chlorophyll-a (ppb)
Total Phosphorus (ppb)
Inlake
0
0
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
Figure 3-14: Phosphorus and Chlorophyll-a Concentrations for Swan Lake North
It is interesting to note that there is a decreasing in-lake phosphorus trend for the north side
of Swan Lake. The in-lake phosphorus concentrations of the north side of Swan Lake do not
seem to follow the same increasing trend as the inlet phosphorus data. This could be explained
by the inlet and outlet locations of Swan Lake. The inlet of Swan Lake is located closer to the
south side of Swan Lake. The Chlorophyll-a concentrations appear to follow a similar trend as
the phosphorus concentrations, but with a slightly less negative slope. These observations are
congruent with the Carlson trophic state plots. Figures 3-12 and 3-14 show that the water quality
of the north side of Swan Lake is improving and the eutrophication process is slowing.
3.3
Two Ocean Lake
Table 3-3: Overview of Two Ocean Lake
Two Ocean Lake
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Carlson, Burns, Vollenweider
and Larsen Mercier
Slightly Increasing
13
Eutrophic
Slightly Increasing
6,896 ft.
86
Trophic State analysis has been performed on Two Ocean Lake over the following years:
1995, 1996, 1997, 2000, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, and 2011. Figures
3-15 through 3-18 show the Carlson trophic state trends for the months of June, July, August and
October during years from 1995 to 2011. Figure 3-19 is a plot of all available Carlson Model
data from Two Ocean Lake with respect to time.
June
70.0
60.0
TSI
50.0
40.0
y = 0.4542x - 856.65
R² = 0.1296
30.0
20.0
10.0
0.0
1990
1995
2000
2005
2010
2015
Year
Figure 3-15: Total TSI Trend for Two Ocean Lake in the Month of June
July
60.0
50.0
TSI
40.0
y = 0.4111x - 776.84
R² = 0.3581
30.0
20.0
10.0
0.0
1995
1998
2001
2004
2007
2010
2013
Year
Figure 3-16: Total TSI Trend for Two Ocean Lake in the Month of July
87
August
80.0
70.0
60.0
TSI
50.0
y = 0.1192x - 186.85
R² = 0.0163
40.0
30.0
20.0
10.0
0.0
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
Year
Figure 3-17: Total TSI Trend for Two Ocean Lake in the Month of August
TSI
October
58.0
57.0
56.0
55.0
54.0
53.0
52.0
51.0
50.0
49.0
48.0
47.0
1995
y = 0.3132x - 576.19
R² = 0.4079
2000
2005
2010
2015
Year
Figure 3-18: Total TSI Trend for Two Ocean Lake in the Month of October
There is a relatively large amount of Carlson trophic state data points for Two Ocean
Lake. All four months, June, July, August, and October show increasing trend lines. The
coefficients of determination are 0.1, 0.4, 0.02, and 0.4 for the months of June, July, August and
October respectively. The coefficient of determination values for July and October are
significant.
88
All Data
70.0
Eutrophic
60.0
TSI
50.0
Mesotrophic
y = 0.2571x - 464.06
R² = 0.0701
40.0
Oligotrophic
30.0
20.0
1994
1999
2004
2009
2014
Year
Figure 3-19: Total TSI Trend for Two Ocean Lake for all Available Data
The trend line for all available data is slightly increasing with a coefficient of
determination at 0.07. The variability of the trophic states of Two Ocean Lake has been high in
recent years. This variability makes it difficult to predict future trophic states with much
precision.
Figure 3-20 shows the inlet phosphorus concentrations for Two Ocean Lake over various
years from 1995 to 2011.
Total Phosphorus (ppb)
Inlet
200
180
160
140
120
100
80
60
40
20
0
1990
y = 3.2104x - 6348.3
R² = 0.1681
1995
2000
2005
2010
2015
Year
Figure 3-20: Total Inlet Phosphorus Concentrations for Two Ocean Lake
89
The inlet phosphorus concentration plot for Two Ocean Lake is highly variable. The
trend line is increasing with a coefficient of determination of 0.2. This is congruent with the inlake trophic state index plots which are also highly variable.
Figure 3-21 shows the trends of the in-lake phosphorus and chlorophyll-a concentrations
for Christian Pond.
Total Phosphorus (ppb)
250
100
200
150
100
80
y = 1.5933x - 3145.8
R² = 0.0619
60
y = -0.1065x + 224.41
R² = 0.0027
40
50
0
1990
20
1995
2000
2005
2010
0
2015
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
Total Chlorophyll-a (ppb)
Inlake
Figure 3-21: Phosphorus and Chlorophyll-a Concentrations for Two Ocean Lake
The coefficients of determination are very low for both phosphorus and chlorophyll-a
concentration trend lines. The trend line for phosphorus is increasing whereas the trend line for
chlorophyll concentration is slightly decreasing. The range of in-lake phosphorus concentrations
is high which is congruent with the inlet phosphorus concentration variability. It appears from
Figures 3-15 through 3-21 that the water quality of Two Ocean Lake is slightly declining.
90
3.4
Christian Pond
Table 3-4: Overview of Christian Pond
Christian Pond
Carlson, Burns, Vollenweider
and Larsen Mercier
Slightly Increasing
8
Strongly Mesotrophic
Slightly Increasing
6,760 ft.
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Trophic State analysis has been performed on Christian Pond over the following years:
1995, 2005, 2006, 2007, 2008, 2009, 2010, and 2011. Figures 3-22 through 3-25 show the
Carlson trophic state trends for the months of June, July August and October during years from
1995 to 2011. Figure 3-26 is a plot of all available data for the Carlson Model with respect to
time.
TSI
June
90.0
80.0
70.0
60.0
50.0
40.0
30.0
20.0
10.0
0.0
1990
y = 1.6895x - 3335.8
R² = 0.5097
1995
2000
2005
2010
2015
Year
Figure 3-22: Total TSI Trend for Christian Pond in the Month of June
91
July
60.0
50.0
TSI
40.0
y = -0.6589x + 1372.9
R² = 0.0873
30.0
20.0
10.0
0.0
2005
2006
2007
2008
2009
2010
2011
2012
Year
Figure 3-23: Total TSI Trend for Christian Pond in the Month of July
August
70.0
60.0
TSI
50.0
y = 0.7265x - 1409
R² = 0.1963
40.0
30.0
20.0
10.0
0.0
1990
1995
2000
2005
2010
2015
Year
Figure 3-24: Total TSI Trend for Christian Pond in the Month of August
92
October
70.0
y = -3.1126x + 6297.4
R² = 0.6905
60.0
TSI
50.0
40.0
30.0
20.0
10.0
0.0
2004
2005
2006
2007
2008
2009
2010
2011
2012
Year
Figure 3-25: Total TSI Trend for Christian Pond in the Month of October
The months of June and August have increasing trophic state trend lines while the months
of July and October have decreasing trend lines. The coefficients of determination are 0.5 and
0.2 for June and August respectively. The coefficients of determination are 0.1 and 0.7 for July
and October respectively. June and October therefore have the strongest correlations.
All Data
80.0
70.0
TSI
60.0
50.0
Eutrophic
y = 0.5549x - 1065
R² = 0.0654
Mesotrophic
40.0
Oligotrophic
30.0
20.0
1994
1999
2004
2009
2014
Year
Figure 3-26: Total TSI Trend for Christian Pond for all Available Data
The plot of all available Carlson trophic state indices shows a slightly increasing trend
line with a coefficient of determination of 0.1. The low coefficient of determination value
proves that this is not a strong increasing correlation.
93
Figure 3-27 shows the inlet phosphorus concentration data with respect to time for
Christian Pond.
Inlet
Total Phosphorus (ppb)
70
60
50
40
30
y = -0.1179x + 267.34
R² = 0.0027
20
10
0
1990
1995
2000
2005
2010
2015
Year
Figure 3-27: Total Inlet Phosphorus Concentrations for Christian Pond
The inlet phosphorus concentrations are highly variable from year to year for Christian
Pond. The coefficient of determination is nearly zero. Although the trend line is decreasing
there is not a strong decreasing correlation in the data. This is congruent with the high variability
in the Carlson trophic state data sets.
Figure 3-28 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
for Christian Pond.
94
Inlake
70
60
200
50
y = 1.8357x - 3634.3
R² = 0.0262
150
100
40
30
y = 0.4619x - 919.08
R² = 0.0198
50
20
10
0
1990
1995
2000
2005
2010
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
Total Chlorophyll-a (ppb)
Total Phosphorus (ppb)
250
0
2015
Figure 3-28: Phosphorus and Chlorophyll-a Concentrations for Christian Pond
The trend lines for both in-lake phosphorus and chlorophyll-a concentrations are slightly
increasing. The coefficients of determination are both fairly low which follows the pattern seen
in the inlet phosphorus concentration data set. The variability of all data sets is common for
Christian Pond. The water quality of Christian Pond seems to be declining slightly since 1995.
It appears however, that the water quality has stayed fairly constant in the years after 1995.
3.5
Cygnet Pond
Table 3-5: Overview of Cygnet Pond
Cygnet Pond
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Carlson, Burns, Vollenweider
and Larsen Mercier
Very Slightly Increasing
9
Strongly Mesotrophic
Slightly Increasing
6,764 ft
Trophic State analysis has been performed on Cygnet Pond over the following years: 1995,
1996, 1997, 2003, 2005, 2008, 2009, 2010, and 2011. Figures 3-29 through 3-31 show the
Carlson trophic state trends for the months of June, July, and August during years from 1995 to
95
2011. Figure 3-32 is a plot of all available Cygnet Pond data from the Carlson Model with
respect to time.
June
70.0
60.0
y = 0.6088x - 1172
R² = 0.4261
TSI
50.0
40.0
30.0
20.0
10.0
0.0
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
Year
Figure 3-29: Total TSI Trend for Cygnet Pond in the Month of June
July
51.0
50.0
TSI
49.0
y = 0.1727x - 299.28
R² = 0.3159
48.0
47.0
46.0
45.0
44.0
1994
1996
1998
2000
2002
2004
2006
2008
2010
Year
Figure 3-30: Total TSI Trend for Cygnet Pond in the Month of July
96
2012
August
70.0
60.0
TSI
50.0
y = 0.0504x - 51.649
R² = 0.0029
40.0
30.0
20.0
10.0
0.0
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
Year
Figure 3-31: Total TSI Trend for Cygnet Pond in the Month of August
Figures 3-15, 3-16, and 3-17 each show that the Carlson trophic state trends are
increasing for Cygnet Pond. As more data is collected in upcoming years the definite trends will
become more apparent. The trophic state indices in 2011 are slightly lower than the trophic state
indices for 2010. For the time being there is enough data to see that since 1995 the Carlson
trophic state is rising.
All Data
70.0
Eutrophic
60.0
TSI
50.0
Mesotrophic
40.0
y = 0.0677x - 86.326
R² = 0.006
Oligotrophic
30.0
20.0
1994
1999
2004
2009
2014
Year
Figure 3-32: Total TSI Trend for Cygnet Pond for all Available Data
The low coefficient of determination shown in Figure 3-32 leaves little room to make a
confident statement that the trophic state of Cygnet Pond is either increasing or decreasing. The
variation in the trophic state values from one year to the next is high but from Figure 3-32 it
97
appears that the trophic state values have historically stayed within a certain range. Figure 3-32
does show that there is a slight increase in the trophic level of Cygnet Pond over all the years
sampled.
Figure 3-33 shows the inlet phosphorus concentration trend with respect to time for
Cygnet Pond.
Inlet
Total Phosphorus (ppb)
35
30
25
y = 0.3656x - 704.83
R² = 0.4817
20
15
10
5
0
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
2014
Year
Figure 3-33: Total Inlet Phosphorus Concentrations for Cygnet Pond
The inlet phosphorus concentration data shows that since 1995 the trend line is
increasing. The coefficient of determination is somewhat significant at a value of 0.48. The
increasing phosphorus concentration is congruent with the in-lake trophic state indices. Still,
more data is needed to make a more accurate observation.
Figure 3-34 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
for Cygnet Pond.
98
Inlake
140
30
120
25
y = 1.3575x - 2681.7
R² = 0.1064
100
80
20
y = -0.1622x + 330.53
R² = 0.0346
60
15
10
40
5
20
0
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
0
2014
Figure 3-34: Phosphorus and Chlorophyll-a Concentrations for Cygnet Pond
The in-lake phosphorus data have an increasing trend line with a coefficient of
determination equal to 0.1. The in-lake phosphorus data is highly variable from one year to the
next. The chlorophyll-a concentration trend line is decreasing with a coefficient of determination
equal to 0.03. It appears from Figure 3-33 that the water quality is slightly decreasing but nearly
constant.
3.6
Emma Matilda Lake
Table 3-6: Overview of Emma Matilda Lake
Emma Matilda Lake
Models Used:
Carlson, Burns, Vollenweider
and Larsen Mercier
Average TSI Trend:
Constant
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
6
Mesotrophic
Increasing
6,873 ft
Trophic State analysis has been performed on Emma Matilda Lake over the following
years: 1995, 2005, 2008, 2009, 2010, and 2011. Figures 3-35 through 3-37 show the Carlson
99
trophic state trends during years from 2002 to 2011 for the months of June, August and October.
Figure 3-38 is a plot of all available Carlson Model data for Emma Matilda Lake with respect to
time.
TSI
June
50.0
45.0
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1994
y = 0.469x - 897.05
R² = 0.9209
1996
1998
2000
2002
2004
2006
2008
2010
2012
Year
Figure 3-35: Total TSI Trend for Emma Matilda Lake in the Month of June
August
46.0
45.0
44.0
TSI
43.0
42.0
41.0
y = -0.2989x + 641.23
R² = 0.845
40.0
39.0
38.0
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
Year
Figure 3-36: Total TSI Trend for Emma Matilda Lake in the Month of August
100
October
60.0
50.0
TSI
40.0
30.0
y = -1.6489x + 3355.1
R² = 0.8385
20.0
10.0
0.0
2004
2005
2006
2007
2008
2009
2010
2011
2012
Year
Figure 3-37: Total TSI Trend for Emma Matilda Lake in the Month of October
The trend line for the June plot is increasing while the trend lines for the August and
October plots are decreasing. There are five data points for the months of June and August,
while there is only three for the month of October. The coefficients of determination are all high
ranging from 0.76 to 0.88.
All Data
Eutrophic
60.0
50.0
TSI
Mesotrophic
40.0
y = 0.0551x - 67.197
R² = 0.0097
Oligotrophic
30.0
20.0
1994
1999
2004
2009
2014
Year
Figure 3-38: Total TSI Trend for Emma Matilda Lake for all Available Data
The plot of all available data for Emma Matilda Lake shows that it is very difficult to
make any inference to whether the Carlson Trophic states are increasing or decreasing. The
trend line is very nearly horizontal with the coefficient of determination nearly equal to zero. It
101
appears that when taking the more recent years into account the trophic states of Emma Matilda
Lake are decreasing. When considering all years however, the trend is increasing.
Figure 3-39 is a graph of the inlet phosphorus concentrations for Emma Matilda Lake.
Total Phosphorus (ppb)
Inlet
100
90
80
70
60
50
40
30
20
10
0
1990
y = 2.6022x - 5175.2
R² = 0.4018
1995
2000
2005
2010
2015
Year
Figure 3-39: Total Inlet Phosphorus Concentrations for Emma Matilda Lake
The inlet phosphorus concentration plot for Emma Matilda Lake has a positive trend line
along with a coefficient of determination of 0.4. This coefficient of determination value is low
for the small amount of inlet data available for Emma Matilda Lake. The variability of this data
is consistent with the variability of the monthly Carlson trophic state trends.
Figure 3-40 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
for Emma Matilda Lake.
102
Total Phosphorus (ppb)
70
6
60
5
y = 0.0132x - 23.635
R² = 0.0035
50
40
4
3
30
2
20
y = -0.4087x + 842.57
R² = 0.0295
10
0
1990
1995
2000
2005
1
2010
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
0
2015
Total Chlorophyll-a (ppb)
Inlake
Figure 3-40: Phosphorus and Chlorophyll-a Concentrations for Emma Matilda Lake
In figure 3-40 the trend line for the phosphorus data is decreasing while the trend line for
the chlorophyll data is slightly increasing. The variability of both the phosphorus and
chlorophyll-a concentration data sets is very high. This is evident with the two coefficients of
determination being close to zero. A change in one or two of the data points could change the
slope direction of these trend lines. It appears from the previous graphs describing Emma
Matilda Lake that its water quality is neither increasing nor decreasing. The eutrophication
process also appears to be neither progressing nor slowing down.
3.7
Oxbow Bend
Table 3-7: Overview of Oxbow Bend
Oxbow Bend
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Carlson and Burns
Decreasing
4
Slightly Mesotrophic
Slightly Increasing
6,760 ft.
Trophic State analysis has been performed on Oxbow Bend over the following years:
1995, 2008, 2010, and 2011. Figure 3-41 shows the Carlson trophic state trend during years
103
from 2005 to 2011 for the month of October. Figure 3-42 is a plot of all available Carlson Model
data for Oxbow Bend with respect to time.
October
60.0
50.0
TSI
40.0
y = 2.6593x - 5302.2
R² = 0.2866
30.0
20.0
10.0
0.0
2007
2008
2009
2010
2011
2012
Year
Figure 3-41: Total TSI Trend for Oxbow Bend in the Month of October
There has not been a significant amount of data collected from Oxbow bend as seen in
Figure 3-41. The coefficient of determination is somewhat significant, with an increasing
trophic state trend line. The water quality trend of Oxbow Bend will become more apparent as
data are added to the analysis.
All Data
Eutrophic
60.0
50.0
TSI
Mesotrophic
40.0
y = -1.2736x + 2604.5
R² = 0.1853
Oligotrophic
30.0
20.0
2004
2006
2008
2010
2012
2014
2016
Year
Figure 3-42: Total TSI Trend for Oxbow Bend for all Available Data
When considering all the years for which data were collected and Carlson trophic states
were determined the trophic state trend of Oxbow Bend is decreasing. The data has a significant
104
amount of variation which makes it difficult to make any firm inferences. The trend does remain
downward however, but more data collected in the future will aid with the level of confidence of
the inferences.
Figure 3-43 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
for Oxbow Bend.
50
6
40
5
4
y = 5x - 10029
R² = 0.25
30
3
20
2
y = 0.1786x - 356.58
R² = 0.015
10
0
2008
2009
2010
1
2011
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
Chlorophyll-a (ppb)
Phosphorus (ppb)
Inlake
0
2012
Figure 3-43: Phosphorus and Chlorophyll-a Concentrations for Oxbow Bend
The trends for both the in-lake phosphorus and chlorophyll-a concentrations are fairly
similar. These two trend lines are increasing with data points showing a similar pattern from
year to year. Figure 3-24 shows that the water quality of Oxbow Bend is maybe improving.
3.8
Taggart Lake
Table 3-8: Overview of Taggart Lake
Taggart Lake
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Carlson and Burns
Very Slightly Increasing
6
Slightly Mesotrophic
Decreasing
6,902 ft.
105
Trophic state analysis has been performed on Taggart Lake during the following years:
1995, 2005, 2008, 2009, 2010, and 2011. Figures 3-44 through 3-46 show the Carlson trophic
state trends for June, August and October during years from 1995 to 2011. Figure 3-47 is a plot
of all available Carlson Model data for Taggart Lake with respect to time.
TSI
June
39.5
39.0
38.5
38.0
37.5
37.0
36.5
36.0
35.5
35.0
34.5
1994
y = -0.1101x + 258.23
R² = 0.1319
1996
1998
2000
2002
2004
2006
2008
2010
2012
Year
Figure 3-44: Total TSI Trend for Taggart Lake in the Month of June
August
39.5
39.0
38.5
TSI
y = 0.0445x - 51.196
R² = 0.1041
38.0
37.5
37.0
1994
1996
1998
2000
2002
2004
2006
2008
2010
Year
Figure 3-45: Total TSI Trend for Taggart Lake in the Month of August
106
2012
TSI
October
42.5
42.0
41.5
41.0
40.5
40.0
39.5
39.0
38.5
38.0
37.5
2004
y = 0.7052x - 1376
R² = 1
2005
2006
2007
2008
2009
2010
2011
2012
Year
Figure 3-46: Total TSI Trend for Taggart Lake in the Month of October
The trophic state trend for the month of June is decreasing while the trend line for August
is increasing. The coefficients of determination for the months of June and August were right
around 0.1. This coefficient of determination value is somewhat low due to the variability in the
data. The trophic state in October 2011 increased since October 2005.
All Data
50.0
Mesotrophic
45.0
TSI
40.0
35.0
y = 0.0189x + 0.1332
R² = 0.0032
Oligotrophic
30.0
25.0
1994
1999
2004
2009
2014
Year
Figure 3-47: Total TSI Trend for Taggart Lake for all Available Data
The data of all the monthly Carlson trophic states show a slightly increasing trend line.
The trend line has a coefficient of determination that is very low. There is too much variability
to make any confident inferences.
Figure 3-48 shows the inlet phosphorus concentration values for Taggart Lake.
107
Inlet
Total Phosphorus (ppb)
30
25
y = -1.2564x + 2529.8
R² = 0.9526
20
15
10
5
0
1994
1996
1998
2000
2002
2004
2006
Year
Figure 3-48: Total Inlet Phosphorus Concentrations for Taggart Lake
The inlet phosphorus concentrations into Taggart Lake show a decreasing trend line from
1995 to 2006.
Figure 3-49 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
for Taggart Lake.
12
7
10
6
8
5
y = 0.0865x - 163.82
R² = 0.2996
6
4
3
4
2
0
1990
2
y = 0.0559x - 109.48
R² = 0.05
1995
2000
1
2005
2010
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
0
2015
Total Chlorophyll-a (ppb)
Total Phosphorus (ppb)
Inlake
Figure 3-49: Phosphorus and Chlorophyll-a Concentrations for Taggart Lake
The in-lake phosphorus concentrations of Taggart Lake have been the same (10 ppb) for all
months except two. These other two months had phosphorus concentrations which were lower
than 10 ppb. This makes the trend line for in-lake phosphorus concentrations positive. The inlake chlorophyll-a concentrations are highly variable from year to year, with a coefficient of
108
determination equal to 0.05. The trend line for chlorophyll-a concentration is slightly increasing,
which is congruent with the in-lake phosphorus concentration trend line. It appears that the
water quality of Taggart Lake might be decreasing very slightly since 1995.
3.9
Moose Pond
Table 3-9: Overview of Moose Pond
Moose Pond
Carlson, Burns, Vollenweider
and Larsen Mercier
Slightly Decreasing
5
Slightly Mesotrophic
Slightly Decreasing
6,896 ft.
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Trophic State analysis has been performed on Moose Pond over the following years: 2002,
2008, 2009, 2010, and 2011. Figures 3-50 and 3-51 show the Carlson trophic state trends for
June and October during years from 2002 to 2011. Figure 3-52 is a plot of all available Carlson
Model data for Moose Pond with respect to time.
June
60.0
50.0
TSI
40.0
30.0
y = 3.9529x - 7901.3
R² = 0.6242
20.0
10.0
0.0
2007
2008
2009
2010
2011
Year
Figure 3-50: Total TSI Trend for Moose Pond in the Month of June
109
2012
October
44.0
43.0
TSI
42.0
y = 0.9761x - 1920
R² = 0.2945
41.0
40.0
39.0
38.0
2007
2008
2009
2010
2011
2012
Year
Figure 3-51: Total TSI Trend for Moose Pond in the Month of October
Figure 3-50 and 3-51 each have three data points with increasing trend lines. The data
points for June and October are also in the same relative positions. The
value of 0.62 for the
month of June shows a strong correlation.
All Data
Eutrophic
60.0
50.0
TSI
Mesotrophic
40.0
y = -0.6199x + 1286.6
R² = 0.0795
Oligotrophic
30.0
20.0
2001
2003
2005
2007
2009
2011
2013
2015
2017
Year
Figure 3-52: Total TSI Trend for Moose Pond for all Available Data
The trend line for all available data is slightly decreasing with a very low coefficient of
determination ( = 0.08).
Figure 3-53 is a graph of the inlet phosphorus concentration data for Moose Pond with
respect to time.
110
Inlet
Total Phosphorus (ppb)
35
30
25
y = -0.4244x + 865.09
R² = 0.0061
20
15
10
5
0
2008
2009
2010
2011
2012
Year
Figure 3-53: Total Inlet Phosphorus Concentrations for Moose Pond
The inlet phosphorus concentrations for Moose Pond have are the same (10 ppb) with the
exception of one year. These concentrations are low and do not necessarily match the high
variability of the in-lake trophic states.
Figure 3-54 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
for Moose Pond.
Total Phosphorus (ppb)
35
10
30
8
y = -0.1282x + 274.59
R² = 0.0014
25
20
6
15
4
10
5
y = -0.5939x + 1196.1
R² = 0.2244
0
2002
2004
2006
2
2008
2010
2012
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
0
2014
Total Chlorophyll-a (ppb)
Inlake
Figure 3-54: Phosphorus and Chlorophyll-a Concentrations for Moose Pond
111
The trend line for the in-lake phosphorus is slightly decreasing while the in-lake
chlorophyll trend line has a more dramatic decrease. The two data plots have low coefficients of
determination which are consistent with the high variability of the Carlson trophic state data
plots. From Figures 3-50 through 3-54 it appears that the water quality since 1995 is improving.
It appears that the water quality of Moose Pond might be declining however, when only
considering the years after 1995.
3.10 String Lake
Table 3-10: Overview of String Lake
String Lake
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Carlson, Burns, Vollenweider
and Larsen Mercier
Increasing
5
Slightly Oligotrophic
Constant
6,870 ft.
Trophic State analysis has been performed on String Lake over the following years: 1995,
2005, 2009, 2010, and 2011. Figure 3-55 shows the Carlson trophic state trend for June, during
years from 1995 to 2011. Figure 3-56 is a plot of all available Carlson Model data for String
Lake with respect to time.
112
TSI
June
38.5
38.0
37.5
37.0
36.5
36.0
35.5
35.0
34.5
34.0
33.5
33.0
1990
y = 0.205x - 375.39
R² = 0.604
1995
2000
2005
2010
2015
Year
Figure 3-55: Total TSI Trend for String Lake in the Month of June
The trend line of the trophic state data in the month of June is increasing with a
coefficient of determination equal to 0.6.
All Data
60.0
Eutrophic
TSI
50.0
40.0
Mesotrophic
y = 0.6026x - 1170.5
R² = 0.2307
Oligotrophic
30.0
20.0
1994
1999
2004
2009
2014
Year
Figure 3-56: Total TSI Trend for String Lake for all Available Data
The trend line of all Carlson trophic state data is also increasing with a coefficient of
determination equal to 0.2. A substantial amount of variability in recent years can also be seen
from Figure 3-56.
Figure 3-57 shows the inlet phosphorus concentrations for String Lake with respect to
time.
113
Inlet
Total Phosphorus (ppb)
12
10
8
6
4
2
0
2009
2010
2011
2012
Year
Figure 3-57: Total Inlet Phosphorus Concentrations for String Lake
The inlet phosphorus concentrations for String Lake have always been 10 ppb. This
gives the trend line a horizontal slope with a coefficient of determination of 1.
Figure 3-58 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
for String Lake.
Total Phosphorus (ppb)
100
18
80
y = 0.2564x - 511.96
R² = 0.1294
60
y = 1.557x - 3104.2
R² = 0.1341
40
1995
2000
8
3
20
0
1990
13
2005
2010
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
-2
2015
Total Chlorophyll-a (ppb)
Inlake
Figure 3-58: Phosphorus and Chlorophyll-a Concentrations for String Lake
114
The in-lake phosphorus and chlorophyll-a concentrations are both increasing with
coefficients of determination slightly higher than 0.1. This is congruent with the Carlson trophic
state index plots which are also increasing. Figures 3-55 through 3-58 show that the water
quality of String Lake is steadily declining and the eutrophication process is progressing. There
seems to be some other mechanism besides the inlet phosphorus that is contributing to the
increases in trophic states of String Lake, since the phosphorus concentrations have always been
the same.
3.11 Bradley Lake
Table 3-11: Overview of Bradley Lake
Bradley Lake
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Carlson and Burns
Decreasing
6
Slightly Oligotrophic
Decreasing
7,022 ft.
Trophic State analysis has been performed on Bradley Lake over the following years:
1995, 2005, 2008, 2009, 2010, and 2011. Figures 3-59 through 3-61 show the Carlson trophic
state trends for the months of June, August and October during years from 1995 to 2011. Figure
3-62 is a plot of all available Carlson Model data for Bradley Lake with respect to time.
115
June
60.0
y = -0.4956x + 1033.9
R² = 0.2098
50.0
TSI
40.0
30.0
20.0
10.0
0.0
1990
1995
2000
2005
2010
2015
Year
Figure 3-59: Total TSI Trend for Bradley Lake in the Month of June
TSI
August
50.0
45.0
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1990
y = -0.3252x + 692.81
R² = 0.2602
1995
2000
2005
2010
2015
Year
Figure 3-60: Total TSI Trend for Bradley Lake in the Month of August
116
TSI
October
39.4
39.2
39.0
38.8
38.6
38.4
38.2
38.0
37.8
37.6
2004
y = -0.2416x + 523.7
R² = 1
2005
2006
2007
2008
2009
2010
2011
2012
Year
Figure 3-61: Total TSI Trend for Bradley Lake in the Month of October
Each of the previous three graphs show a decreasing trend line in the Carlson trophic
state indices. The June plot of Carlson trophic state indices has the most data out of the three
monthly plots. The coefficient of determination for the month of June is 0.2. This value is low
due to the variability of the data in recent years.
All Data
Eutrophic
60.0
50.0
TSI
Mesotrophic
40.0
30.0
20.0
1994
y = -0.3648x + 771.61
R² = 0.2209
1999
Oligotrophic
2004
2009
2014
Year
Figure 3-62: Total TSI Trend for Bradley Lake for all Available Data
The plot of all available Carlson trophic state indices for Bradley Lake indicates there is a
decreasing trend line in the data with a coefficient of determination equal to 0.2. This coefficient
of determination value is due to the variability of the data in 2010 and 2011.
Figure 3-63 is a plot of the inlet concentrations from Bradley Lake with respect to time.
117
Inlet
Total Phosphorus (ppb)
16
y = -0.4058x + 823.85
R² = 0.8526
14
12
10
8
6
4
2
0
1994
1996
1998
2000
2002
2004
2006
Year
Figure 3-63: Total Inlet Phosphorus Concentrations for Bradley Lake
The decreasing inlet phosphorus concentration trend line is consistent with the decreasing
in-lake Carlson trophic state trend line.
Figure 3-64 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
for Bradley Lake.
Total Phosphorus (ppb)
35
10
30
y = -0.3366x + 689.38
R² = 0.0779
25
8
20
6
15
4
10
5
0
1990
2
y = -0.2237x + 451.69
R² = 0.4872
1995
2000
2005
2010
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
0
2015
Total Chlorophyll-a (ppb)
Inlake
Figure 3-64: Phosphorus and Chlorophyll-a Concentrations for Bradley Lake
The data for in-lake phosphorus concentration is highly variable with a low coefficient of
determination ( =0.08). The trend line for in-lake phosphorus is decreasing however which is
118
consistent with inlet phosphorus concentration data. The trend line for in-lake chlorophyll
concentration is also decreasing with a coefficient of determination of 0.5. The data from 2010
once again makes the coefficient of determination lower with its relatively high values among its
neighboring data points. The water quality of Bradley Lake is improving according to Figures
3-38 through 3-43. This implies that the eutrophication process in Bradley Lake is slowing.
3.12 Phelps Lake West
Table 3-12: Overview of Phelps Lake
Phelps Lake
Carlson, Burns, Vollenweider
and Larsen-Mercier
Decreasing
5
Oligotrophic
Decreasing
6,633 ft.
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Trophic State analysis has been performed on Phelps Lake over the following years: 1995,
2003, 2005, 2008, 2009, and 2011. Figures 3-65 and 3-66 show the Carlson trophic state trends
for June and August during years from 1995 to 2011. Figure 3-67 is a plot of all available
Carlson Model data for Phelps Lake with respect to time.
119
TSI
June
45.0
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1993
y = -0.7258x + 1489.9
R² = 0.998
1995
1997
1999
2001
2003
2005
2007
2009
2011
Year
Figure 3-65: Total TSI Trend for Phelps Lake in the Month of June
August
37.0
36.0
y = -0.0176x + 69.844
R² = 0.0008
TSI
35.0
34.0
33.0
32.0
31.0
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Year
Figure 3-66: Total TSI Trend for Phelps Lake in the Month of August
The Carlson trophic state plot for the month of June shows a decreasing trend line. The
coefficient of determination is high but there are only three data points. The data points for the
month of August are highly variable with the trend line being almost flat.
120
All Data
Eutrophic
60.0
TSI
50.0
y = -0.5719x + 1181.7
R² = 0.6111
Mesotrophic
40.0
Oligotrophic
30.0
20.0
1994
1999
2004
2009
2014
Year
Figure 3-67: Total TSI Trend for Phelps Lake for all Available Data
It can be seen from Figure 3-67 that the Carlson trophic state trend line is decreasing for
all data with a coefficient of determination of 0.6. This coefficient of determination value is
moderately significant. It appears that the trophic state indices for Phelps Lake are decreasing
when considering all data. There is still a certain amount of variability among the more recent
years and more data collection will reveal if this downward trend continues.
Figure 3-68 shows the inlet phosphorus data for Phelps Lake with respect to time.
Inlet
Total Phosphorus (ppb)
11
10
9
y = 0.0084x - 7.1179
R² = 0.0047
8
7
6
5
4
1995
2000
2005
2010
Year
Figure 3-68: Total Inlet Phosphorus Concentrations for Phelps Lake
121
2015
The inlet phosphorus concentrations for Phelps Lake have been low during every year in
which the inlet was sampled. The trend line is nearly flat and there is not a lot of change in the
inlet phosphorus concentrations for Phelps Lake.
Figure 3-69 shows the trends in the in-lake phosphorus and chlorophyll-a concentrations
for Phelps Lake.
Total Phosphorus (ppb)
14
5
y = 0.2646x - 521.79
R² = 0.2326
12
4
10
3
8
6
4
2
y = -0.0944x + 190.48
R² = 0.2799
1
2
0
1990
1995
2000
2005
2010
Phosphorus
Chlorophyll-a
Linear (Phosphorus)
Linear (Chlorophyll-a)
0
2015
Total Chlorophyll-a (ppb)
Inlake
Figure 3-69: Phosphorus and Chlorophyll-a Concentrations for Phelps Lake
The in-lake phosphorus concentration is consistent with the inlet phosphorus
concentrations. Both the in-lake phosphorus and inlet phosphorus data plots are constant over
the years after 1995. Data in 1995 was highly variable which reduces the coefficient of
determination. The trend line for in-lake phosphorus is increasing while the in-lake chlorophylla is decreasing. These data series are not consistent and would also imply that phosphorus may
not be the limiting nutrient in Phelps Lake. It appears from Figures 3-65 through 3-69 that the
water quality of Phelps Lake is improving.
122
3.13 Lake of the Crags
Table 3-13: Overview of Lake of the Crags
Lake of the Crags
Carlson, Burns, and
Larsen-Mercier
Slightly Decreasing
2
Oligotrophic
Not Applicable
9,565 ft.
Models Used:
Average TSI Trend:
Number of Years Sampled:
2011 Average Trophic State:
Inlet Phosphorus Trend:
Surface Elevation:
Trophic State analysis has been performed on Lake of the Crags over the following years:
1995 and 2011. Figure 3-70 shows the Carlson trophic state trend during years in 1995 and 2011
for the month of August. Figure 3-71 is a plot of all available Carlson Model data for Lake of the
Crags with respect to time.
August
50.00
45.00
TSI
40.00
35.00
y = -0.0084x + 47.499
R² = 1
30.00
25.00
1994
1999
2004
2009
2014
Year
Figure 3-70: Total TSI Trend for Lake of the Crags in the Month of June
We can see from Figure 3-70 that the trophic state of Lake of the Crags in 2011 is slightly
lower than 1995. This is not a large change with the difference between the trophic state indices
being about 0.13. There is clearly not enough data however for Lake of the Crags to make any
confident inferences.
123
All Data
50.00
Mesotrophic
45.00
TSI
40.00
35.00
y = 0.0464x - 62.705
R² = 0.196
Oligotrophic
30.00
25.00
1994
1999
2004
2009
2014
Year
Figure 3-71: Total TSI Trend for Lake of the Crags for all Available Data
Lake of the Crags was sampled twice in 1995 and once in 2011. The data collected in July
of 1995 was lower than the other two data points. Since trophic state indices depend highly on
the month and time of year Figure 3-70 would be more representative of the water quality trend
than Figure 3-71. Based on Figure 3-71 the water quality of Lake of the Crags is improving.
124
125
4
CONCLUSIONS
In 2011 there were 14 bodies of water sampled in Grand Teton National Park. There was
a large range of trophic values calculated for these bodies of water. The south side of Swan Lake
had the highest trophic state (eutrophic), and Lake of the Crags had the lowest trophic state
(oligotrophic).
Table 4-1 shows the trophic state classification calculated for each body of water sampled
in 2011. Table 4-1 also lists each lake in order of decreasing trophic state, with the exception of
Swan Lake North.
Table 4-1: 2011 Trophic States
Body of Water
Swan Lake South
Swan Lake North
Two Ocean Lake
Christian Pond
Cygnet Pond
Emma Matilda Lake West
Oxbow Bend
Taggart Lake
Moose Pond
String Lake
Bradley Lake
Phelps Lake
Arrowhead Pond
Ramshead Lake
Lake of the Crags
2011 Trophic State Classification
Eutrophic
Slightly Eutrophic
Eutrophic
Strongly Mesotrophic
Strongly Mesotrophic
Mesotrophic
Slightly Mesotrophic
Slightly Mesotrophic
Slightly Mesotrophic
Slightly Oligotrophic
Slightly Oligotrophic
Oligotrophic
Oligotrophic
Oligotrophic
Oligotrophic
In Table 4-1 there are two bodies of water classified in the eutrophic range, six bodies of
water classified in the mesotrophic range and six bodies of water classified in the oligotrophic
range. This proves that the majority of the selected lakes in Grand Teton National Park are in a
relatively healthy state, and would support complex aquatic habitat such as fish. These lakes
could also be used as recreation areas and serve as possible potable water sources.
Table 4-2 shows the 2011 trophic states for the selected lakes in Grand Teton National
Park along with the corresponding elevation of each lake or pond.
126
Table 4-2: 2011 Trophic States and Corresponding Elevations
Body of Water
Swan Lake South
Swan Lake North
Two Ocean Lake
Christian Pond
Cygnet Pond
Emma Matilda Lake West
Oxbow Bend
Taggart Lake
Moose Pond
String Lake
Bradley Lake
Phelps Lake
Arrowhead Pond
Ramshead Lake
Lake of the Crags
2011 Trophic State Classification
Eutrophic
Slightly Eutrophic
Eutrophic
Strongly Mesotrophic
Strongly Mesotrophic
Mesotrophic
Slightly Mesotrophic
Slightly Mesotrophic
Slightly Mesotrophic
Slightly Oligotrophic
Slightly Oligotrophic
Oligotrophic
Oligotrophic
Oligotrophic
Oligotrophic
Elevation (ft.)
6,796
6,796
6,896
6,760
6,764
6,873
6,760
6,902
6,896
6,870
7,022
6,633
9,170
9,524
9,565
As the elevation of a body of water increases the trophic state often decreases. This can
be explained by the watershed area which contributes to a specific lake. As the elevation of a
lake increases the watershed area contributing to a lake generally decreases. Nutrients contained
within the watershed could be transported to a lake in a rainfall event. With a larger contributing
watershed area, and possibility of nutrients, the trophic state is often higher.
Table 4-3 shows a list of selected lakes in Grand Teton Park and the corresponding
trophic state trend. Arrowhead Pond and Ramshead Lake are not included in Table 4-3 since
only one year of data (2011) is available for each of these bodies of water.
127
Table 4-3: In-Lake Trophic State Trends
Body of Water
Swan Lake South
Swan Lake North
Two Ocean Lake
Christian Pond
Cygnet Pond
Emma Matilda Lake West
Oxbow Bend
Taggart Lake
Moose Pond
String Lake
Bradley Lake
Phelps Lake
Lake of the Crags
In-Lake Trophic State Trend
Slightly Decreasing
Decreasing
Slightly Increasing
Slightly Increasing
Slightly Increasing
Constant
Decreasing
Slightly Increasing
Slightly Decreasing
Increasing
Decreasing
Decreasing
Slightly Decreasing
The lakes which have increasing trophic state trends are lakes in which the eutrophication
process is progressing. This could be of potential concern, especially for those lakes which are
experiencing dramatic increases or have high coefficients of determination. The coefficient of
determination defines how well a set of data points fits a trend line. The coefficient of
determination is defined in equation 4-1. None of the lakes or ponds is experiencing a dramatic
increasing trophic state trend.
(4-1)
Where
= coefficient of determination
= regression sum of squares
= total sum of squares
String Lake has the highest increasing trophic state trend line slope. The trend line for
String Lake also has a relatively high coefficient of determination, equal to 0.2. These
parameters are shown in Figure 3-56. The trophic state of String Lake in 2011 is classified as
slightly oligotrophic, and therefore is not presently of major concern.
Table 4-4 shows the inlet phosphorus trends for selected lakes in Grand Teton National
Park. Arrowhead Pond, Ramshead Lake and Lake of the Crags are not included in Table 4-4
because the Inlet of each of these lakes/ponds has only been sampled once, in 2011. Oxbow
128
Bend is also not included in Table 4-4 since it is part of the Snake river and has a different
configuration than the other lakes and ponds.
Table 4-4: Inlet Phosphorus Trends
Body of Water
Swan Lake South
Swan Lake North
Two Ocean Lake
Christian Pond
Cygnet Pond
Emma Matilda Lake West
Taggart Lake
Moose Pond
String Lake
Bradley Lake
Phelps Lake
Inlet Phosphorus Trend
Increasing
Increasing
Slightly Increasing
Slightly Decreasing
Slightly Increasing
Increasing
Decreasing
Slightly Decreasing
Constant
Decreasing
Decreasing
There are several explanations why a lake might be experiencing increasing trophic state
trends. This could be due to the increasing inlet phosphorus trends, agricultural runoff, or
another type of animal or human interaction. Looking at the combination of in-lake trophic state
trends and inlet phosphorus trends can help give an explanation as to why a body of water is
experiencing increasing or decreasing trophic state trends. There are four combinations which
can take place among these two trends. Both the in-lake trophic state and inlet phosphorus trend
lines could be increasing or decreasing, one could be increasing while the other is decreasing and
vice versa.
The lakes which are experiencing increasing in-lake trophic state trends but decreasing
inlet phosphorus trends must have a mechanism other than the inlet phosphorus trend which
contributes to the increasing in-lake trophic state trends. Lakes which fall under this category
include Christian Pond, Taggart Lake, and String Lake. The cause of increasing trophic state
trends for these three lakes and pond could be human or animal interaction.
There are also several lakes/ponds which are experiencing increases in both in-lake
trophic state and inlet phosphorus trends. Lakes which fall under this category include Two
Ocean Lake and Cygnet Pond. In the case of these lakes the inlet phosphorus trends could be
contributing to the increasing in-lake trophic state trends. This doesn’t rule out the possibility of
other human interaction having an influence on the increasing trophic state trends however.
The mechanism describing lakes which have decreasing trophic state trends and
increasing inlet phosphorus trends relates to the nature of the dispersion and/or retention of a
particular lake. The lakes which fall under this category include Swan Lake, and Emma Matilda
129
Lake. The inlet phosphorus concentrations do not seem to have a large effect on these two
bodies of water. This could be due to short circuiting. Short circuiting occurs when the inlet
flow enters a lake but minimal dispersion occurs before the inlet flow leaves the lake through an
outlet.
The last possibility is that the in-lake trophic state and inlet phosphorus trends are both
decreasing. The lakes/ponds which are experiencing this trend combination include Bradley
Lake, Phelps Lake, and Moose Pond. The most likely explanation of this occurrence is that the
inlet has a large effect on the lake and a large amount of dispersion is occurring. This trend
combination also reveals that there is most likely minimal human and animal interaction
occurring within these three bodies of water.
The previous discussion is summarized in Table 4-5.
Table 4-5: In-Lake and Inlet Trend Explanations
In-Lake
trophic state
and Inlet
phosphorus
trends
Explanation
Bodies of
water in this
category
Increasing Inlake trophic
state trend and
Increasing inlet
phosphorus
trend
In-lake trophic
state trend could
be explained by
inlet phosphorus
trend or another
form of human
interaction
Increasing Inlake trophic
state trend and
Decreasing inlet
phosphorus
trend
In-lake trophic
state trend could
be due to human
interaction, but
not inlet
phosphorus
trend
Two Ocean
Lake, Cygnet
Pond
Christian Pond,
Taggart Lake,
String Lake
130
Decreasing Inlake trophic
state trend and
Decreasing inlet
phosphorus
trend
Decreasing Inlake trophic state
trend and
Increasing inlet
phosphorus trend
In-lake trophic
state trend could
be due to the
inlet phosphorus
trend
In-lake trophic
state trend could
be due to short
circuiting
between the inlet
and lake
Moose Pond,
Bradley Lake,
Phelps Lake
Swan Lake,
Oxbow Bend,
Emma Matilda
Lake
131
REFERENCES
Vesilind, P. Aarne, J. Jeffrey Peirce, and Ruth F. Weiner.,1994, "Effect Of Pollution On Lakes."
Environmental Engineering. Boston [u.a.: Butterworth-Heinemann, 49-53.
Environmental Protection Agency. (2009, December 28). Aquatic Biodiversity. Retrieved July
23, 2011, from United States Environmental Protection Agency:
http://www.epa.gov/bioindicators/aquatic/carlson.html
Burns, J.R. (1999). A monitoring and classification system for New Zealand Lakes and
Reservoirs. Lake and Reservoir Management , 255-271.
Vollenweider, R. (1968). Fundamentals of the eutrophication of lakes and flowing water, with
particular reference to N and P as factors in eutrophication. Paris, France: Technical Report
(OECH).
"Google Maps." Google Maps. N.p., n.d. Web. 13 July 2013.
"Introduction." RVcruzer.com. N.p., n.d. Web. 13 July 2013.
Flickr. Yahoo!, n.d. Web. 13 July 2013.
"Hiking." About.com. N.p., n.d. Web. 13 July 2013.
"Introduction." RVcruzer.com. N.p., n.d. Web. 13 July 2013.
"Welcome to Jackson Hole." Jackson Hole Wyoming. N.p., n.d. Web. 13 July 2013.
"The American Southwest." - Arizona, California, Colorado, Idaho, Nevada, New Mexico,
Oregon, Texas, Utah, Wyoming. Slot Canyons & Travelogue. N.p., n.d. Web. 13 July 2013.
132
5
APPENDIX A. TABULATED DATA
Dr. Woodruff Miller of BYU has collected samples during various years starting in 1995
to2011. The data collected from these years is tabulated below for future comparisons. Data from
other lakes in Grand Teton National Park which were not sampled in 2011 can be found at
http://www.et.byu.edu/~jjp87/Teton%20Study/Teton_Index.htm.
A.1 Raw Data from 1995 through 2011
133
Swan Lake South
Table 5-1: Raw Data for Swan Lake South
In-lake
Year
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
1997
1996
1996b
1995
Month
June
July
August
October
June
July
August
September
June
July
August
October
June
July
August
October
August
October
June
July
May
July
August
October
June
July
August
September
May
June
Beg. Aug
End Aug.
September
July
August
October
June
July
August
June
July
August
October
August
October
June
July
August
September
October
Phosphorus
(ppb)
40
30
20
30
30
20
20
20
40
30
20
30
30
20
20
20
40
30
30
30
30
40
20
20
40
40
20
30
40
30
30
20
20
18
16
Chlorophyll-a
(ppb)
2.7
4.4
3.6
5.6
4.2
2.4
3.2
2
7.3
4.9
2.5
6.7
2.1
1.6
4.4
4.4
5.1
1.9
3.1
6.5
11.7
2.3
9.9
9
12.7
1.9
3.1
3.9
2.5
3.8
2.9
4.7
5.6
7.1
3.4
5.7
3.7
3.4
2.6
3
2
5.6
4.6
5.5
2.8
1.7
4.2
4.7
2.5
31.2
73.08
77.32
20
20
130
29
10
20
12.5
18
63
18
40
134
Secchi Depth
(meters)
2
2
2
2
2.5
3.5
3.5
3.5
2
2.5
3
2
2.5
2.5
2.5
2.5
1.5
2.5
2
2.5
2
2
2.5
2
1.5
1.25
2.5
2
2
3
2.5
2
2
2
2.5
3.5
2
2
2
2
2
2
2
2
2
1.5
1.5
1.5
1.5
1.5
Inlet
Year
2011
2010
2009
2008
2007
2004
2003
2002
1997
1996
1995
Month
HRT (yrs)
June
July
August
October
June
July
August
September
June
July
August
October
June
July
August
October
August
October
June
July
August
September
May
June
August
September
July
August
June
July
August
June
July
August
October
June
August
September
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
135
Total Inflow Phosphorus
(ppb)
110
290
210
90
100
160
150
90
200
280
100
140
100
210
130
110
150
90
130
150
80
250
100
60
115
70
40
30
97.4
109.5
100
90
90
60
16.5
26.5
11
14
Swan Lake North
Table 5-2: Raw Data for Swan Lake North
In-lake
Year
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
Month
June
July
August
October
June
July
August
September
June
July
August
October
June
July
August
October
August
October
June
July
January
May
July
August
October
June
July
August
September
May
June
Beg. Aug
End Aug.
September
July
August
October
December
Phosphorus
(ppb)
40
30
20
30
20
20
20
20
30
30
20
40
40
20
20
20
30
40
30
30
40
40
30
20
30
50
60
60
30
60
50
120
40
40
35
124
64
136
Chlorophyll-a
(ppb)
2.7
4.4
3.6
5.6
4.1
1.8
1.8
1.5
4.2
2.4
2
7.6
5.6
2.4
2.1
3.1
2.8
7.6
1.3
6.5
7.1
8.1
2.3
2.4
7.3
5
9.5
9.4
4.7
8.3
6.8
33.8
6.8
4.7
12.6
21.7
18.1
19.15
Secchi Depth
(meters)
2
2
2
2
2.5
2.5
2.5
2.5
2
2.5
3
2
1.5
2.5
1.5
2.5
1.5
2.5
1.5
1.5
1.75
1.5
2
2
2
1
1.5
1.5
1
1
1.5
1
1.5
1.75
1.5
2
2.5
1
Inlet
Year
2011
2010
2009
2008
2007
2004
2003
2002
1997
1996
1995
Month
HRT (yrs)
June
July
August
October
June
July
August
September
June
July
August
October
June
July
August
October
August
October
June
July
August
September
May
June
August
September
July
August
June
July
August
June
July
August
October
June
August
September
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
137
Total Inflow Phosphorus
(ppb)
110
290
210
90
100
160
150
90
200
280
100
140
100
210
130
110
150
90
130
150
80
250
100
60
115
70
40
30
97.4
109.5
100
90
90
60
16.5
26.5
11
14
Two Ocean Lake
Table 5-3: Raw Data for Two Ocean Lake
In-lake
Year
2011
2010
2009
2008
2007
2006
2005
2004
2003
2000
1997
1996a
1996b
1995a
1995b
Month
June
July
August
October
June
July
August
September
October
June
July
August
October
June
July
August
October
August
October
June
May
June
July
August
October
June
August
June
June
July
August
June
July
August
October
June
July
August
October
June
August
September
June
August
September
Phosphorus
(ppb)
100
20
50
70
30
50
30
30
80
200
50
100
30
40
30
30
20
40
50
30
80
70
40
30
20
130
40
27
35.87
46.21
165.19
10
10
17
20
10
10
10
16
70
25
36
60
22
34
138
Chlorophyll-a
(ppb)
42.5
2.1
6.5
11.9
4.7
8.8
6.7
2.2
11.5
21.8
4.6
12.5
11.6
8
5.9
4.8
8.6
11.5
7.4
3.3
20
19
5.6
3.6
10.6
7.1
8.5
7.7
4.8
2.1
79.6
1.3
4.8
15.3
18.5
1.2
4.8
13.3
16.3
15.4
3.2
7.3
16.2
3.7
6
Secchi Depth
(meters)
2
3
2
2
3.5
3.5
2
2.5
3.5
2
2
2
2
2
3.5
2.5
2.5
4.5
2.5
2.5
2
2
2
2.5
2
3
1.5
2
2
3.5
2
2
4
3.5
2.5
2
3.5
2
3.5
1.5
2
3.5
1.5
2.5
3
Inlet
Year
2011
2010
2009
2008
2007
2006
2005
2003
2000
1997
1996
1995
Month
HRT (yrs)
June
July
June
June
June
July
August
June
May
June
July
August
June
June
July
August
June
July
August
October
June
August
September
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
139
Total Inflow Phosphorus
(ppb)
143
150
185
40
53
130
60
130
50
90
60
8
50
80
77
122
120
60
90
60
77
12
20
Christian Pond
Table 5-4: Raw Data for Christian Pond
In-lake
Year
2011
2010
2009
2008
2007
2006
2005
1995
Month
June
July
August
October
June
July
August
September
October
July
August
October
June
July
August
October
August
October
July
Apr
June
August
October
June
August
Phosphorus
(ppb)
210
40
40
20
20
40
110
30
20
20
10
20
30
80
160
10
60
40
50
80
40
30
90
19
23
Chlorophyll-a
(ppb)
63.2
2.5
4.8
1.8
2.4
2.7
6.8
2
1
3.4
1.3
3.8
33.1
5.2
12.6
1.6
4.7
3.8
4.2
14.7
6.4
1.1
27.3
0.5
1.1
140
Secchi Depth
(meters)
2
2
2
3
2.5
3.5
3.5
3.5
3
3
4
3
2.5
1.5
1.5
2.5
2.7
2.5
3.5
2
1.5
3
2
3
2
Inlet
Year
Month
HRT (yrs)
2011
June
June
July
August
October
July
August
June
July
August
October
August
June
July
June
August
October
June
August
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
2010
2009
2008
2007
2006
2005
1995
141
Total Inflow Phosphorus
(ppb)
20
30
30
30
20
30
30
30
20
30
20
60
40
40
30
30
40
38
15
Cygnet Pond
Table 5-5: Raw Data for Cygnet Pond
In-lake
Year
2011
2010
2009
2008
2005
1997
1996
1995
Month
June
July
August
June
July
August
September
June
July
August
October
June
July
August
October
May
August
August
June
August
October
June
July
August
September
October
Phosphorus
(ppb)
60
30
30
80
30
50
90
60
30
10
30
40
60
40
10
130
30
43.86
10
10
16
20.5
37
28
30
35
Chlorophyll-a
(ppb)
0.6
1.7
5.5
6.1
3.5
5
14.8
8.7
3.2
1.1
6.3
2.2
2.8
26.1
2.8
8.6
4
3.4
1.2
4.8
16.3
1.1
0.5
5
2.3
2.3
Secchi Depth
(meters)
3
2
2
2.75
2.75
2.75
2.75
1
2.5
3
2
1.5
2.5
2
2.5
1
2
2
2
2
2
1.5
1.5
1.5
1
1
Inlet
Year
Month
HRT (yrs)
2011
2008
1996
June
June
June
June
July
0.2
0.2
0.2
0.2
0.2
1995
Total Inflow Phosphorus
(ppb)
30
30
30
23
22
142
Emma Matilda Lake
Table 5-6: Raw Data for Emma Matilda Lake
In-lake West
Year
Month
June
August
October
June
July
August
June
July
August
October
August
June
July
October
June
August
2011
2010
2009
2008
2005
1995
Phosphorus
(ppb)
20
10
20
30
20
20
20
30
10
10
10
20
30
60
21
21
Chlorophyll-a
(ppb)
3.1
2.3
1
4.5
1.5
1.7
3.5
3
2.4
3.2
4
2.6
2.4
4.8
1
3.35
Secchi Depth
(meters)
3
4
3
3.5
3.5
3.5
3
3
3
4
3.5
3
3.5
4
5
3.5
In-lake East
Year
Month
2009
2005
July
July
June
August
1995
Phosphorus
(ppb)
30
30
14
16
Chlorophyll-a
(ppb)
3
2.4
1.2
3
Secchi Depth
(meters)
3
3
4
2
Inlet
Year
Month
HRT (yrs)
2011
2010
2009
2005
June
June
June
June
June
August
5
5
5
5
5
5
1995
143
Total Inflow Phosphorus
(ppb)
40
50
50
90
10
9
Oxbow Bend
Table 5-7: Raw Data for Oxbow Bend
In-lake
Year
Month
2011
2010
October
October
August
October
April
2008
2005
Phosphorus
(ppb)
20
40
40
10
40
Chlorophyll-a
(ppb)
1
5
5.4
1.3
8.5
Secchi Depth
(meters)
3
2.5
3.5
3
2
Inlet
Year
2009
2008
2007
2006
2005
1995
Month
HRT (yrs)
July
August
June
July
August
October
August
June
July
June
August
October
June
August
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
0.3
144
Total Inflow Phosphorus
(ppb)
30
30
30
20
30
20
60
40
40
30
30
40
38
15
Taggart Lake
Table 5-8: Raw Data for Taggart Lake
In-lake
Year
2011
2010
2009
2008
2005
1995
Phosphorus
(ppb)
10
10
10
10
9
10
10
10
10
10
10
7
10
Month
June
October
June
August
June
August
June
May
June
August
October
June
August
Chlorophyll-a
(ppb)
1.7
6.2
4.1
2
1.2
2.9
2.1
3
1.3
2.7
1.7
2.9
1.9
Secchi Depth
(meters)
5
4
5.5
4.5
5
6
4.5
5
5.5
4
4
3
5
Inlet
Year
Month
HRT (yrs)
2005
June
June
August
0.6
0.6
0.6
1995
Total Inflow Phosphorus
(ppb)
10
21
24
Moose Pond
Table 5-9: Raw Data for Moose Pond
In-lake
Year
2011
2010
2009
2008
2002
Month
June
October
June
August
July
August
October
June
August
October
July
Phosphorus
(ppb)
30
20
30
10
10
10
20
10
10
10
26
Chlorophyll-a
(ppb)
1.7
1.5
9.5
0.6
1.6
0.7
2.4
0.7
2.9
1
8.3
145
Secchi Depth
(meters)
3
3
3.5
4.5
3
4
3
4.5
2.5
2.5
3
Inlet
Year
2011
2010
2009
2008
Month
HRT (yrs)
June
October
June
August
July
August
October
June
August
October
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
Total Inflow Phosphorus
(ppb)
10
10
10
10
10
10
30
10
10
10
String Lake
Table 5-10: Raw Data for String Lake
In-lake
Year
Month
2011
June
June
July
August
September
June
April
May
August
June
August
2010
2009
2005
1995
Phosphorus
(ppb)
10
10
30
10
90
10
10
30
10
4
4
Chlorophyll-a
(ppb)
2.1
2.3
3.5
0.7
14.8
0.9
0.6
0.5
1.3
0.7
0.5
Secchi Depth
(meters)
5
5
2.75
3.5
2.75
5
5
5
5
2
2
Inlet
Year
Month
HRT (yrs)
2011
June
June
August
June
0.01
0.01
0.01
0.01
2010
2009
146
Total Inflow Phosphorus
(ppb)
10
10
10
10
Bradley Lake
Table 5-11: Raw Data for Bradley Lake
In-lake
Year
2011
2010
2009
2008
2005
1995
Month
June
October
June
August
June
August
June
May
June
August
October
June
August
September
Phosphorus
(ppb)
10
10
30
20
10
10
10
10
10
10
10
29
13
17
Chlorophyll-a
(ppb)
0.5
2.3
4.2
3.2
2
1.4
1.7
2.7
1.2
2.9
2.6
5.7
7.8
3.2
Secchi Depth
(meters)
5
5
2.5
3.5
5
6
4.5
5
5.5
4.25
4
4
3.5
4.5
Inlet
Year
Month
HRT (yrs)
2005
June
June
August
0.4
0.4
0.4
1995
Total Inflow Phosphorus
(ppb)
10
15
13
Phelps Lake
Table 5-12: Raw Data for Phelps Lake
In-Lake West
Year
2011
2009
2008
2005
2003
1995
Month
June
August
June
July
August
July
July
October
August
June
September
Total Phosphorus
(ppb)
10
10
10
10
10
10
10
10
8
12
0
Total Chlorophyll-a
(ppb)
0.5
1.7
0.6
0.8
0.6
0.5
0.8
1.4
1.8
3.9
0.5
147
Secchi Depth
(meters)
7
5
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
In-Lake East
Year
2005
1996
1995
Total Phosphorus
(ppb)
10
10
10
10
4
4
Month
June
July
June
August
June
September
Total Chlorophyll-a (ppb)
2.6
0.9
0.4
1
10
0.5
Secchi Depth
(meters)
4.5
5
5
8
3
10
Inlet
Year
Month
HRT (yrs)
2011
2011
June
August
June
July
August
July
October
June
June
August
June
September
8
8
8
8
8
8
8
8
8
8
8
8
2009
2005
2003
1996
1995
Total Inflow Phosphorus
(ppb)
10
10
ND
ND
ND
10
10
8
10
10
72
244
Arrowhead Pond
Table 5-13: Raw Data for Arrowhead Pond
In-lake
Year
Month
2011
August
Phosphorus
(ppb)
10
Chlorophyll-a
(ppb)
0.5
Secchi Depth
(meters)
6
Inlet
Year
Month
HRT (yrs)
2011
August
0.1
148
Total Inflow
Phosphorus (ppb)
10
Ramshead Lake
Table 5-14: Raw Data for Ramshead Lake
In-lake
Year
Month
2011
August
Phosphorus
(ppb)
10
Chlorophyll-a
(ppb)
0.5
Secchi Depth
(meters)
6
Inlet
Year
Month
HRT (yrs)
2011
August
0.1
Total Inflow Phosphorus
(ppb)
10
Lake of the Crags
Table 5-15: Raw Data for Lake of the Crags
In-lake
Year
Month
2011
August
July
August
1995
Phosphorus
(ppb)
10
8
9
Chlorophyll-a
(ppb)
0.5
0.5
0.6
Secchi Depth
(meters)
6
6
6
Inlet
Year
Month
HRT (yrs)
2011
August
0.1
149
Total Inflow
Phosphorus (ppb)
10