MARINE ALGAL NUTRIENT REGENERATION•
THE ENRICHMENT OF THE WATER SURROUNDING
ANO NUEVO ISLAND, CALIFORNIA BY PINNIPEDS
by
John C, Hansen
A thesis
submitted in partial
fulfillment of the requirements for the degree of
Master of Arts in the Department of Biology
Fresno State College
May, 1972
ACKNOWLEDGMENTS
Doctor G, Victor Morejohn is gratefully acknowledged for his initial suggestion to do this study, for his
general guidance and continual help throughout the course
of the study, and for his constructive criticism of this
manuscript.
A special thanks goes to Dr. Bert A. Tribbey,
my thesis committee chairman.
His vital aid in communications
and logistics at the Fresno campus .has made my entire
program possible,
The Henry H. Bradleys, Coastways Ranch,
Pescadero, California, are sincerely thanked for helping to
save much effort and critical time by furnishing transportation to and from Ano Nuevo Point at any time, day or night,
The help of Dr. Mary W, Silver and James B. Jensen was also
gratefully received throughout the course of this study and
during the preparation of this manuscript.
For all his help with sea water chemistry, thanks
are given to Mr. David B. Seielstad, Moss Landing Marine
Laboratories,
Thanks are given to Mr. Paul Baba, Sanitation
and Radiation Laboratory, State Department of Public Health,
Berkeley, California, who arranged for his staff to analyze
the bacteriological samples,
Without his cooperation, the
bacteriological aspect of this study would not have been
possible to conduct.
Thanks are also given to Mr. Frank
Monnich of the research vessel, Amigo,and to Dr, Roy Gordon,
San Francisco State College, for furnishing respectively the
iv
nautical and the aerial perspectives of Ano Nuevo and Pigeon
Point,
A final thanks goes to Mrs. Judith E. Hansen, a
good wife and co-worker.
TABLE OF CONTENTS
page
ACKNOWLEDGMENTS
LIST OF TABLES
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LIST OF FIGURES •
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Section
INTRODUCTION
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MATERIALS AND METHODS • • • • • •
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Components of the Investigation
The Sampling Program
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Methods of Data Analysis
RESULTS •
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Sources of Other Data • • • • • • • • •
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Analysis of Fecal and Urinary Degradation •
Analysis of Samples •
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Speculations and Recommendations for Further Research
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DISCUSSION
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Interpretation of Results • • • • •
Conclusions
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SUMMARY , • • • •
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LITERATURE CITED
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APPENDIX A
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APPENDIX B
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APPENDIX C
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TABLE OF CONTENTS (continued)
APPENDIX D
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APPENDIX E
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APPENDIX F
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LIST OF TABLES
page
Table 1,
Results of Statistical Analyses
Table 2.
Results of Degradation Study , • •
Table J,
A comparison of nutrient values from Ana
Nuevo and Pigeon Point with other areas
eoteoolil
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LIST OF FIGURES
Figure
page
1.
Sampling station locations • • , • • , • • , ,
2,
Apparatus used to study the short-term degradation rates of pinniped feces and urine in
s ea water
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12
3·
Concentrations of NHTN at Aii.o Nuevo and
Pigeon Point ' ' • • • • • • • • • • • • • • •
20
4.
Concentrations of NOj-N at Ano Nuevo and
Pigeon Point • • • • • • • • • • • • • • • • •
21
5.
Concentrations of NOz-N at Ano Nuevo and
Pigeon Point • • • • • • ' • • • • • • • • • •
Concentrations of PoJ--P at Ano Nuevo and
Pigeon Point • • • • • • • • • • • • • • • • •
22
7·
Total coliform counts at Ana Nuevo and
Pigeon Point • • • • • • • • • • • • • • • • •
22
s.
Fecal coliform counts at Ano Nuevo and
Pigeon Point • , • • • • • • • • • • • ' • •
Fecal streptococcus counts at Ano Nuevo
and Pigeon Point • • • • • • • • • • • • • • •
6.
9.
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21
23
23
10.
Pinniped biomass at ATio Nuevo Island ,
24
11,
Pinniped populations at Ano Nuevo Island , • •
24
12.
Wind stress index for the Ario NuevoPigeon Point vicinity • • , • , • , • • • • •
25
1J,
Regression of NOj-N (PP) on Noj-N (ANP), , • ,
29
14.
Regression of N02-N (PP) on NOz-N (ANP) •• , •
29
15.
Regression of
16,
Regression of Noj-N (ANP) on
17.
Regression of Noj-N (PP) on
18,
Pod--P
(PP) on PoJ--P (ANP), • •
Pod--P (ANP),
Pod--P (PP). ,
29
• •
29
• •
30
Regression of NH -N (ANP) on FC (ANP), , , , ,
3
30
ix
LIST OF FIGURES (continued)
Regression of NH -N (ANP) on PB , , ,
3
, •
• • .30
..'
30
20.
Regression of FC (ANP) on PB
21.
Degradation rate of urea-N in sea water ,
• •
32
22.
NHi-N production from the degradation of
ur!§a in' sea water .. • , a •
o
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~~ a •
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production from the degradation of
feces in sea water , . . . . o a • o • • , • • •
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23.
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-·
Poa--P
INTRODUCTION
The chemical composition of sea water has been
described as being relatively constant with respect to the
ratios of the major components (Dittmar,
188~).
There
are, however, certain of the minor constituents of sea
water which are less conservative and may vary substantially
with time and location.
There are a number of physical
factors related to water movement which affect the concen-
.
trations of minor constituents, but major fluctuations
ultimately result from biological processes (Harvey, 1966).
Two of the minor sea water constituents which
display large variations in concentrations are the compounds
of nitrogen and phosphorus.
Since these compounds are also
major plant nutrients, their concentrations in sea water can
indicate the degree of fertility of the water.
Brandt {1899)
was among the first to suggest that, with reference to
"Liebig's La>1 of the Ninimum,
r;
the growth of marine algae in
the euphotic zone is often limited by the availability of
nutrients, especially nitrogen and phosphorus,
Brandt's
suggestion has since been well substantiated by Harvey (1928;
19~0),
Cooper (1933), Chu
(19~9),
and others.
The concentrations of nitrogen as nitrate (Noj-N)
and phosphorus as phosphate (PO~--P) in the open ocean and
in upwelled coastal waters have been found to occur in an
2
average ratio of 15:1 respectively (Redfield, 19}4: Cooper,
1938; Vaccaro, 1963).
I
Fleming (1940) and Stafansson and
Richards (1963) found the same ratio in the uptake of NOj-N
and PO,--P by phytoplankton.
Some researchers have, however,
found ratios. other than 15':1 in both phytoplankton and sea
water (Riley, 1951; Ryther and Dunstan, 1971) and have
raised doubts concerning the validity and usefulness of this
ratio.
Ryther and Dunstan reviewed the reports containing
evidence contrary to a general 15:1 ratio, and made special
reference to a 5.6:1 ratio for Noj-N and Po4--P uptake in
laboratory cultures of Chlorella pyrenoidosa (Ketchum and
Redfield, 1949).
They also emphasized the variations of the·
ratio from 2.9:1 for nitrogen-deficient cells, to 30.1:1 for
phosphorus-deficient cells in laboratory cultures.
On the
basis of these laboratory reports, Ryther and Dunstan discounted the NOj-N to Po2--P ratio of 15:1 as a general occurrence in the oceans.
The.neglected to note, however, that
the works they cited were conducted in waters deficient or
depleted of one or more nutrients,
They also ignored the
works of Fleming (1940) and others with phytoplankton communities and waters not depleted of nutrients.
Moreover,
the work of Ryther and Dunstan was conducted in the "polluted"
waters of Moriches Bay, Long Island, which by definition are
altered by "unnatural" processes,
From the above discussion, it is clear that natural
or unnatural alterations of surface waters may cause variations
from the 15:1 ratio both in the nutrient uptake by phytoplankton and in the water,
However, the fact remains that
J
recently upwelled waters have a characteristic 1511 average
ratio of NO}-N to Pod--P.
The processes replenishing nutrients to the depleted
surface waters are of vital significance to algal production,
Although the redistribution of nutrient-rich water is of a
physical nature, the actual remineralization of organic
compounds mainly resuLts from biological processes,
The
importance and the functioning of marine bacteria in the
regeneration of nutrients have been studied and reviewed by
Zebell (19*6, 1959).
The studies have indicated that the
biological remineralization of algal nutrients from organic
matter is accomplished predominantly by marine bacteria,
In the marine nitrogen cycle, the first stage in the
regeneration of inqrganic :.nitrogen is the deamination of
organic nitrogenous compounds (Cooper, 19J7); the resultant
ammonia-nitrogen (NH -N) is then, at aphotic depths, succes-
3
sively oxidized by bacteria to nitrate-ni!rogen (N02-N) and
finally to NOj-N.
All three forms of inorganic nitrogen,
NH -N, N02-N, and NOj-N may be available to algae as a
3
nitrogen source (Syrett, 1962; Round, 1966),
Phosphorus is
utilized by .algae primarily in the inorganic form as orthophosphate (Poa--P), although other forms may also be absorbed
(Chu, 1946; Harvey, 195Ja,b),
In contrast to nitrogen,
Po4--P may be regenerated at any depth in the water column
(Redfield, Smith, and Ketchum, 19)7),
One aspect in the biology of marine nutrient regeneration, with few exceptions, was largely neglected until
4
the last decadet the regeneration of algal nutrients by
marine animals.
Nearly all the published works on this
nutrient regenerating source are concerned with the nitrogen
and phosphorus compounds contributed by zooplankton.
These
works have been reviewed by Vaccaro (1965), Harvey (1966),
Johannas (1968), and Jawed (1969),
that
They have indicated
PO~--P is available directly from zooplankton excreta
and is also released immediately upon the death of marine
organisms,
The available nitrogen contributed by zooplankton
is predominantly in the form of NH -N, with little urea or
3
other forms of utilizable organic nitrogen,
Investigations
of any similar effects caused by marine birds or mammals have
not been previously reported.
Among the marine birds and mammals, the eared and
earless seals (Order Pinnipedia) are ideal subjects for
studies related to the regeneration of algal nutrients,
Pinnipeds are primarily adapted to an aquatic existence,
although they may spend considerable periods of time at
hauling-out grounds and rookeries for the purposes of
breeding, molting, or giving birth to young,
Unlike com-
parable congregations of marine birds, pinnipeds may deposit
large amounts of nutrient materials directly into the water,
as described below,
One such pinniped hauling-out ground
is located at Ano Nuevo Island, on the coast of central
California, where as many as 14,000 seals have been counted
in one day 1 s census (Orr and Poulter, 1965),
The species
composition of the breeding and non-breeding populations of
5
the island normally include Zalophus californianus, Eumetopius
iubata, Mirounga angustirostris, and Phoca vitulina,
individuals of Callorhinus ursinus have
occasionall~
Isolated
been
reported (Orr and Poulter, 1965).
Although some pinniped excretory material is found
on Ano Nuevo Island, observations of the excretory behavior
of the animals have indicated a strong tendency for the
animals to eliminate excreta upon entering the water (personal communications by G.V. Morejohn, 1970; R,L, Gentry,
1971),
Since the animals seldom wander far from the edge of
the water to the upper parts of the island, any excreta
deposited on the island is likewise seldom far from the water.
The fact is that considerable volumes of excreta are deposited
in the waters around ADo Nuevo Island,
These observations, among others, have resulted in
instigating the hYPothesis for this and another study,
conducted concurrently and in collaboration (J. E. Hansen,
1971)1 The pinnipeds of Ano Nuevo Island stimulate standing
crops of eulittoral benthic algae at Ano Nuevo Point by
increasing the concentrations of available nutrients,
This
hypothesis has been divided into two complementary components
which were investigated separately! (1) The pinnipeds are
responsible for the nutrient enrichment of the waters of
Ano Nuevo;
(2) Stanting crops of eulittoral benthic algae
are increased as a result of nutrient enrichment,
component is supported by this study, the
complementary study by J,E, Hanseri,
latte~
The former
by the
6
It was further hypothesized that the NH 3-N would be
a good indicator of nutrient enriched water, and that the
presence of fecal coliform bacteria would indicate whether
the enrichment resulted from pinniped excreta or from some
other source.
Although Wd -N is excreted only in very small
3
quantities by mammals, the primary excretory product, urea,
either dissociates to NH -N in sea water (Cooper, 1937) or
3
is decomposed to NH -N by urea-splitting bacteria (Zobell and
3
Feltham, 1935). To substantiate the hypothesis that NH 3-N
would be a good indicator of nutrient enrichment by pinniped
excreta, laboratory analyses of the initial components and the
degradation products of fresh pinniped feces and urine were
performed.
The nutrient enrichment of sea water is not an
absolute quality of the water, but a relative quality,
The
determination of the quality of the waters around Ano Nuevo
with respect to enrichment implies, therefore, the necessity
of a non-enriched control for comparison.
Since a duplicate
of Ano Nuev.o Island which is not frequented by pinnipeds is
non-existent, the choice of any other control site would be
somewhat less than ideal.
An area near Pigeon Point, nine
kilometers north of Ano Nuevo,was found to have most of the
major environmental characteristics in common with Ano Nuevo
Point,
MATERIALS AND METHODS
Components of the Investigation
The data required for this investigation were of
two types: (1) data which had been previously accumulated
and made available by other investigators, and (2) data
which were not previously available and had to be obtained
from the field and from laboratory experimentation.
The
field data included the concentrations of two of the major
plant nutrients dissolved in sea >'later, .nitrogen (NH -N,
3
NOj-N, and NOz-N) and phosphorus (PO,--P).
other field
data included concentrations of intestinal bacteria in sea
water, specifically the fecal coliform and fecal streptococcus
groups,
Total coliform bacteria data were also obtained,
All field data were obtained through collection.
Laboratory investigations of the short-term (24 hour)
degradation rate of fresh pinniped feces and urine were conducted to determine the production of dissolved inorganic
nitrogen (NH 3 -N, Noj-N, and Noz-N) and phosphorus (Po,--P),
The data that were obtained from other sources
include the census of pinniped populations on'Ano Nuevo
Island, weight·estimates (each age group and sex of each
species) of the pinniped populations, and the mean daily
wind direction and wind velocity data for the Ano NuevoPigeon Point vicinity.
8
The Sampling Program
The sampling program was divided into two parts,
experimental and control.
The experimental site for this
investigation was located at Ano Nuevo Point, 64 km south
of San Francisco, California, and 0.5 km northeast of Ano
Nuevo Island (Figure 1).
The eulittoral extention of the
point has a substrate composed of Miocene cherty shale
(Brabb, 1970).
Depressed areas. in the shale are overlain
with large cobbles in a sandy matrix,
Wave shock in the
intertidal area of Ano Nuevo Point is diminished as compared to the more exposed open coast due to the protection
provided by Ano Nuevo Island,
During very low tides (i,e.
below -1,0 ft), a large area of the point is exposed.
This
area is over 0,25 km wide, which is one,.ha,lf the distance
to Ano Nuevo Island.
Samples of sea water were obtained fro~
within one meter of the surface of the water at the most
seaward extention of AUo Nuevo Point,
The control site for the investigation was located
8.5 km north of Ano Nuevo Point and 0.3 km south of the
lighthouse at Pigeon
Point·~·(Figure
1),
The substrate,
although differing slightly in composition and considerably
in age (Brabb, 1970), is not markedly dissimilar to that of
Ano Nuevo Point for the purposes of this study.
At the Pigeon
Point location, 47 m of intertidal are exposed during very low
tides,
The wave shock is comparable to that occurring at Allo
Nuevo Point due to the protection provided by the proximity of
9
San
Fra.ncisc
Pay
nterey
Pay
Ano Nuevo .!\>..!:'-. $
Island -...._,.
0
1
4
2
kilometers
Figure 1.
Sampling station locations.
10
Pigeon Point and by a large rock outcropping (30 m X 15m)
at the northern boundary of the sampling location.
The lack
of large numbers of pinnipeds in the immediate vicinity of
Pigeon Point was the most significant factor that differentiated the intertidal environments at Pigeon Point from
that at Ano Nuevo Point,
The investigation covered the period from February,
1970 1 to March, 1971.
Water samples were taken at Ano Nuevo
Point and at Pigeon Point on the two consecutive days of the
lowest monthly tides.
The nutrient samples were taken in
screw-capped polyethylene bottles of 500 ml capacity,
When
each of the samples was taken, the sample bottle was rinsed
thoroughly in the water to be sampled,
All nutrient samples
were frozen within two hours after sampling and remained
frozen until just prior to analysis,
Samples for bacteriological analysis were normally
taken in duplicate each month at both stations.
These
samples were obtained aseptically in heat sterilized 100 ml
glass bottles with parchment covered lids,
Immediately
after sampling, the bacteriological samples were placed into
an ice chest and transported to the Sanitation and Radiation
Laboratory of the California State Department of Public
Health in Berkeley, California, for analysis,
The
bac~·­
teriological analyses were usually begun within six hours
after sampling,
11
Analysis of Fecal and Urinary Degradation
Figure 2 is the design of the apparatus used for the
analysis of the degradation rates of feces and urine.
The
apparatus was constructed in. duplicate for the simultaneous
duplication of the experiments.
~wo
five-gallon (19 1)
capacity glass bottles were used as reaction tanks.
a half-
gallon (2 1) per minute water pump was used on each tank to
circulate and agitate the contents of the tank,
To prevent
biological or chemical depletion of dissolved oxygen during
the course of the experiment, the contents of each tank were
aerated by attaching an air siphon to the return tube from
the circulating water pump.
The air entering the system was
first bubbled through a 250 ml bottle containing SO% (v/v)
HCl to remove all traces of volitile NH • A similar NH
3
3
trap was used to capture any volitile NH from the exhaust
3
air.
The exhaust NHJ trap contents were retained during each
sampling interval for future analysis of the accumulated NH
3
content, and the trap replaced,
On 9 February 1972, a yearling harbor seal (Phoca
vitulina) was captured on the beach at Moss Landing,
animal was placed into a cage over an enameled pan,
The
Within
one hour, the reaction tanks were filled with fresh sea
water collected one mile offshore from Moss Landing, fresh
urin.e and feces were collected from the captured animal, and
the experiment was begun.
Tank-I was inoculated with 2 g
(wet weight) of feces and 1 ml of urine.
Tank-II was
inoculated with 4 g of feces and 2 ml of urine,
The tanks
12
water
pump
air
siphon
-""'
....,..
air
exhaust
NH 1 trap
19 1
capacity
Figure 2.
Apparatus used to study the short-term degradation;--.
rates of pinniped feces and urine in sea water,
13
were darkened during the experiments to prevent an excessive
nutrient uptake by phytoplankton.
The reaction tanks were each sampled just prior to
inoculation,
just subsequent to inoculation, and at 1, 6, 12,
and 24 hours after inoculation,
At each sampling period,
eight 50 ml samples and the exhaust air NH -trap samples were
3
collected from each tank,
Each sample was placed into an
acid-washed 25 X 200 mm glass culture tube, sealed and frozen
for future analysis,
Six of each group of eight samples
corresponded to six separate analyses: organic-N, urea-N,
NH 3-N, NO)-N, N02-N, and POa--P.
The remaining two samples
from each group were stored for future reference.
Aliquots
of the original fecal and urine samples were also frozen
and stored for future reference.
The analysis of each of
the samples was done in duplicate (except Noj-N and No; -·N).
The limit of 24 hours duration was chosen for the
degradation experiments for two reasons:
( 1) The natural. ·
continuous dilution of materials deposited in the ocean
could not be simulated in the reaction tanks;
(2) Data on
the degradation of material for longer periods of time would
not be relevant to the present study since such latent
products of degradation would have been transported from
the location of sampling at Ano Nuevo.Point.
Due t6 the failure of the urea-N analysis for the
above samples, a separate analysis of the degradation rate
of urea was necessary.
In this experiment, 1 ml of the
original urine sample was added to 4 1 of sea water in an
amber glass bottle of
4.3 1 capacity.
The bottle was kept
14
in a refrigerator at
and occasionally shaken to prevent
One 100 ml sample was taken at each
oxygen depletion.
sampling period:
13 0 c
just prior to inoculation,
just sub-
sequent to inoculation, and at 1, 4, 12, and 24 hours after
inoculation,
Each sample was analyzed immediately upon
collection for urea-N and NH -N.
Each of the analyses was
3
done in triplicate,
Analysis of Samples
The methods used for the bacteriological sample
analyses by the Department of Public Health were those
described in Recommended Procedures for the Bacteriological
Examination of Seawater and Shellfish (APHA, 1962), and in
Standard Methods for the Analysis of Water and Wastewater
(APHA, 1965).
The concentrations of total coliforms, fecal
coliforms, and fecal streptococci
1~ere
each recorded as the
most probable number (MPN) of cells per 100 ml.
The most appropriate methods for the analysis of
nutrients in sea water (except NR -N) vrere found to be those
3
recommended by Strickland and Parsons (1968).
for
PO~--P
The procedure
determinations was that described by Murphy and
Riley (1952),
The method for Noj-N determinations was
adoptEd from that described by Wood, Armstrong, and Richards
(1967),
Bendschneider and Robinson {1952) had described
the method used in this study for the determination of N02~N.
i
A method described by Solorzano (1969) was found to be the
most appropriate one for the critical NHJ-N analyses in
15
this study.
Although the method is less sensitive than some
others, the inherent simplicity of the method more than
compensates by greatly reducing the sources of contamination
that are associated with other methods.
of
The concentrations
PoiJ.--P,
Noj-N, N02-N, and NR -N found in the samples were
3
each recorded as micrograms-atoms per liter (~g-at/1).
McCarthy (1970) combined a urease hydrolysis of urea with
I
the NH -N method of Solorzano (1969). This technique was used
3
in the present study in the urea-N degradation analyses.
The use of a more highly refined urease preparation was
successfully substituted for Jl!cCarthy's complicated technique
for the purification of URC lyophilized jack bean meal
urease.
A satisfactory established method for the determination of organic-N at low levels was not found although
several variations were tried.
The method developed for this
study combined a variation of the Kjeldahl digestion which
was followed by an adjustment of the pH to 8.) and a subsequent NH -N determination as described above. Adjustment
3
of the results for the initial NH -N concentration yields the
3
concentration of organic-N. Replicate analyses of standard
solutions containing glycine and monosodium L-glutamate
revealed a digestion efficiency of 95±5% of the calculated
standard concentrations.
16
Sources of Other Data
The most recent data, given below, for the populations of Zalophus californianus, Eumetapius jubata, and
Phaca vitulina at Ana Nuevo Island covered the period from
September, 1967, to September,1968.
Recent comprehensive
census data are nat available; however, recent observations
in 1969 and 1970 by students and staff of the University of
California at Santa Cruz have indicated that the average
monthly seal populations on Ana Nueva Island fluctuate little
from one year to the next (personal communication by R.L.
Gentry, 1970).
The Zalophus californianus census data
differentiated adult males from females and juveniles (Lance
and Peterson, 1968).
The males were distinctive but the
females could not be differentiated from juveniles without
closer inspection.
Census data for Eumetopius jubata were
subdivided into several categories: adult males, subadult
'
males, females, yearlings, and pups (Gentry, 1968a).
Adult
male and female Phoca vitulina were not distinguishable from
one another without closer inspection and were censused
together (Gentry, 1968b),
The census of Mirounga angustirostris populations
was conducted concurrently with this investigation (personal
communication QY B.J. LeBoeuf, 1971).
These data were also
subdivided into several categories: adult males, adult
females, juveniles, weaners, pups, and others,
11 others 11
The category
applied to non-breeding populations in which females
17
and various juvenile forms were not readily distinguishable
from one another,
Average weight estimates for individuals representing
each of the species, sex, and age categories of the
1971) and for
census (personal communication by R.L. Gentry,
each of the categories of the
1967-68
1970-71 Mirounga angustirostris
census (personal communication by B.J, LeBoeuf,
1971) were
also obtained,
The mean daily wind direction and wind velocity
data for the period corresponding to the present study were
obtained from the United States Coast Guard lighthouse
facility at Pigeon Point,
Methods of
D~ta
Analysis
The pinniped census data and the estimated weight
data were mathematically reduced to mean monthly pinniped
biomass (kilograms) at Ano Nuevo as follow1
Mean monthly pinniped biomass (PB)
=
~
Mi
where,
and;
Mi
= biomass
of each species, sex and age
category of the pinnipeds.
= number of individuals of category "i"
in each day "t" of census for the month.
m
=
d
= the
estimated biomass of an individual
representing category "i",
number of days "t" in the month that
category "i" was included in the census,
18
From the mean daily wind direction and wind velocity
data, a mean monthly wind stress index was calculated,
Hidaka (1958) developed the index for studies of: the Ekman
Wooster and Reid (196)) used
transport in the Pacific Ocean.
the wind stress index successfully as an indicator of
upwelling.
The following formula was constructed for use
in this study, also as an indicator of upwelling,
The wind stress Index for each month equalsa
L: (cos
e ,
Vi)
2
N
where;
.cos
e
.
= the cosine of the angle (degrees )
defined by the difference between
NWN and the actual mean direction
the wind is from on day "i" (for
e ~ 90°, cos e is reduced to zero),
Vi= mean wind velocity on day "i"•
N = number of days in each month.
Statistical testing was used to support the analyses
of the data, and included both parametric and non-parametric
tests.
The parametric statistics (linear regression analyses,
student t-test, and the f-test) were described by Woolf
(1968), and the
non~paramatric
test
(Kendall's tau) has been
described by Tate and Clelland (1959).
RESULTS
The results of the nutrient analyses, NH -N, NOj-N,
3
NOz-N• and Po4--P concentrations are summarized in Fugures
J, 4, 5, and 6 respectively,
The sources of data for these
figures are listed in Appendices A, B,
c, and D respectively.
Figures 7, 8, and 9 represent the resultant bacteriological
data, concentrations of total coliforms, fecal coliforms, and
fecal streptococci respectively,
Appendix E includes a
comprehensive listing of all bacteriological data.
Figure 10
represents the monthly distribution of pinniped biomass (PB)
at Ano Nuevo Island for the period corresponding to this
study (see also Appendix F).
These data show the contributions
of each of the three major species as well as the composite
of all three.
Data on Phoca vi tulina 1-rere omitted from
Figures 10 and 11 since their contributions to the totals
were less than one per cent.
In Figure 11, the pinniped census
data are displayed in a manner similar to Figure 10.
Census
data are included here to show the differences between
numbers of pinnipeds and the biomass (Figure 10) which they
represent,
Table 1 summarizes all the statistical tests applied
to the data, their respective results and significance.
Figures 13 through 20 show the results of the significant
linear regression analyses described in Table 1.
The following is a list of symbols and abbreviated
20
terms used in this section (in addition to those previously
noted) to simplify the presentation of the analytical resultsr
FC
= ADo Nuevo Point
= regression coefficient
= fecal coliform bacteria
FS
=
fecal streptococcus bacteria counts
p
=
the probability (per cent) of a true
null hypothesis of a statistical test
PB
=
mean monthly pinniped biomass at
ADo Nuevo Island
PP
=
Pigeon Point
TG
=
total coliform bacteria counts
ANP
b
~ADo
counts
Nuevo Point
OPigeon Point
30-
2520.--!
~
I
"'
~
-1-'
al
I
15-
'
'
10-
til
::1.
·,
5"
ii
'\
'
J'.
'i
:i
o~[~,n~~h~rr~~~~~~h~h~·~~·~~
M-A
1970
J
J
·Figure J,·
d
~
J
1971
Concentrations of NH 3 -N at Ano Nuevo and Pigeon Point,
21
2 4-
201-
rl
'Z'I
I<'"\
0
16)'
12:-
z
...,
ul
I
·,
'
J
81-
t{)
::1,
4'.
'
10<
0
.'
Jl
I
F M-A
i
·~
I
}I
J
1970
.
.
J
!•
..,.
'•
A
s
'
'
0
N
~
..
r
-t
i:
:·.
"--.!
'
'
'
'
D'
F
J
M
1971
Figure 4
Concentrations of NOj-N at ATio Nuevo and Pigeon Point.
0. 6-
0.5rl
'Z'!
IN
0
z
...,
ul
i
-1
0.4:-
'•
0.3-
r
0.2-
bO
::1,
·~
0.1-
o.o ~
F
1970
·,1;
M-A M
x:
<l
~:
,:.
·l
1
f1
'j
..~
'•~-;
'·
',•
'
t
~;
,.
.j
w;:·
•;.
I
J
t~-
!•:
f·
'·
';
J
'·
'
A
')
s
·:l.
s
Figure 5.
0
N
D
J
M
F
1971
Concentrations of NOz-N at ATio Nuevo and Pigeon Point.
22
].0-
2. 52.0-
.-l
'
fl.
I
I
~
0
fl.
1.5~.
t
+>
1. 0-
al
I
,.'
btl
::3,.
r'
0.5-
'
!,
"
·~
l\1
..
J
o.o
F
N-A ~~
'
,,
\
\II
J
1970
b
J
h
~
~·
~~
D
F
J
M
1971
Figure 6.
Concentrations of Po4--P at Ano Nuevo and Pigeon Point.
150-
9J-
4J0
E-l
~
15i
7-
t
;~
<J-
L
:.:;
a
1970
l•T-"A
M
I
J
,;'
'~-
'
'
','I"
·1
:·
'}
t5
0
F
'
~
'·
;;
'
;'
~
:~
'·
~-
J
A
s
I
0
I
N
D
J
F
M
197.1
Figure 7.
Total coliform counts at Allo Nuevo and Pigeon Point.
2)
4) .
27
-
9
-
'
.
i
'
-
-.
:::
"
4
',
<) .
.,'•,
'·
''
'
F
N-A
'
.
M
J
1970
,•
'
(
;'
'
f
'
(
.'.-,
"'
0
'
'
'1
'
'
;!
J
A
;\
'•
,(
i
'
'
)
b
N-
D
J
~
F
1971
Figure 8,
Fecal coliform counts at Ano Nuevo and Pigeon Point,
4) .
.
27
;
'
15 i'
-
'
'
'
•
.;
7-
~-
.
.,
'
'
<)
'
..'
1¥1
1;.1
~~
.,
.
.,
0
F
1970
M-A
M
.
.
i
J
J
A
s
Figure 9,
0
N-
I
!
.
1:
i
!
.,
;'
j'
D
J
F
I\
1971
Fecal streptococcus counts at Ano Nuevo and Pigeon Point.
24
15.
12.
"',...
0
10.
:X:
It)
,;.::
l
?.5
p:j
P<
l
i'
o.o
~;:',",.'
F
M
)>1
J
J
s
A
'"~
.
0
-~
·-
N
Figure 10.
Pinniped biomass at Ana Nuevo Island,
Mirounga
Eumetopias
'
angustirostris
.1ubata
N
0
~ Zalophus
~ californianus
Ul
rl
til
,g
6.0
.p...;
....;
'g
....;
'H
0
H
ID
.n
~
10
"r"l._ ·--·
0
Figure 11,
Pinniped populations at Ana Nuevo Island.
25
90 75
-
-
...-
;.;
r-
Ql
qj
,::::
H
rn
rn
Ql
1-<
60
-
45
-
r-r-
+-'
('f.)
qj
,::::
.....
r-
,.....
JO -
-
,...-
;3:
.....
15 0
rr-
hI
F
1970
I
M
'·
A
I
M
I
J
I
J
I
A
sI
I
0
I
N
I
D
I
J
I
. I
F
M
1971
Figure 12.
Wind stress index for the ADo Nuevo-Pigeon Point vicinity,
Table 1
Results of Statistical Analyses
Hypothesis Tested
Statistical
Test
Coefficient
The cone. of NH~-N at ANP
and PP are not elated,
Kende.ll' s
tau.
The cone, of NO~-N at ANP
and PP are not elated,
linear
regression
b = 1.225
The regression of PP No -N
3
on ANP NOrN '/- 1.00.
student
t-test
tb= 0,824
The cone. of NO~-N at ANP
and PP are not elatelli
linear
regression
b
The regression of PP N02-N
on ANP N02-N F 1.00·
student
t-test
tb= 1,089
The cone, of PO~--P at ANP
and PP are not related·
linear
regression
b
The regre~sion of PP PoJ--P
on ANP PO --p t 1.00·
student
t-test
tb"" 0.555
At ANP the cone, of NHt-N
and NO}-N are not rela ed.
Kendall's
tau
At ANP NOj-N and poJ--P
are not related.
.
linear
regression
b
The rJ~ression of#NO~-N
on PO -P at ANP . 1 ,00~
student
t-test
tb= 0.4-57
Probability
Text
Figure
p>0,20
= 0.821
"'
0,822
•
,Ol>p>.005
12
0.5>p>O,J
,Ol>p>.005
13
0 .5>p>O. 3
.05>p>.025
14
O,?>p>0,5
0,2>p>0.1
= 13.514
.01>p>.005
0, 7>p>O. 5
15
1\l
~
Table 1 (continued)
Coefficient
Probability
Hypothesis Tested
Statistical
Test
At PP the cone, of NH -N
and NO}-N are not rela~ed,
Kendall's
tau
P>0.2
At PP ~~e cone, of NH 3-N
and PO~ -P are not related,
Kendall's
tau
p>O.;:: ..
At PP ~he cone. of No1-N
and PO#--P are not related.
linear
regression
The r;~ression of N03-N
on P04 -P at PP = 1,.ooo.
student
t-test
TC at ANP and PP are not
related,
Kendall's
tau
p>0.2
FC at ANP and PP are not
related.
Kendall's
tau
p>0.2
FS at ANP and PP are not
related,
Kendall's
tau
0.2>p>0,1
Cone, of NH -N at ANP are
not related 3 to FC at ANP.
linear
regression
The regression of ANP NH3-N
on ANP FC I 1,000,
student
t-test
p<,Ol
The cone, of N01-N at ANP
and ANP FC are tiot related,
Kendall's
tau
p>0.2
The cone. of NH 3-N at PP
and PP FC are not
related
linear
regression
0.5>p>0.25
b
= 15.159
b = 0,886
i
.Ol>p>,005
• 025>p>. 01
Text
Figure
16
17
Table 1 (continued)
Coefficient
Probability
Hypothesis Tested
Statistical
Test
The cone, of NOl-N at PP
and PP FC are n6t related.
Kendall's
tau
The cone, of NH3-N at ANP
are not related to PB.
linear
regression
The regression of NH -N at
ANP on PB 1 1,000, 3
student
t-test
The cone, of }lli 3-N at PP
are not related to PB
Kendall's
tau
0, 2>p>O ,1
The cone. of No;-N at ANP
and PB are not related
Kendall's
tau
p>0.2
The cone, of Noj-N at PP
are not related to PB
Kendall's
tau
p>0,2
FC at ANP are not related
to PB
linear
regression
.01>p>,005
The regression of.ANP FC
on PB 'I 1,000
student
t-test
.02>p>.01
FC at PP are not related
to PB
Kendall's
tau
p>0,2
Cone, of Poz--P at PP are not
related to wind stress index
Kendall's
tau
p>0.2
Cone, of PoJ--P at ANP are not
related to wind stress index
Kendall's
tau
p>0.2
Text
Figure
p>0.2
b = L704-
.05>p>.025
18
19
29
fl.
fl.
24
~
fl.
fl.
~
r-l
'
zI
I <'"\
0
~
18
r-l
a!
I
tO
::1..
12
0.4
z
0.2
0
IN
0
+>
6
0
'z
I
z
+>
o.6
0 ..
a!
i
tO
:I..
0
0
12 18 24
}lg-e.t NOj-N/1 (ANP)
0
0.2
0.4 0.6
0
)Jg-e.t N02-N/l (ANP)
Figure 1J,
Regression of NO~-N
(PP) on NOj-N (A P),
Figure 14,
Regression of NO~-N
(PP) on N02-N (A P),
2.8
16
2.1
12
1.4
8
0.7
0
.
+--r---.--.-...,
0 0.7 1.4 2.1 2.8
pg-at Po2--P/l (ANP)
.
0
4
0 +--"..;of!--,,..--,,..---,
0.7 1.4 2.1 2.8
)Jg-e.t Po4--P/l (ANP)
0
Figure 15,
Figure 16,
Regression of PO~--P
(_PP) on PO~- -P (ANP).
Regression qr NO)-N
(ANP) on PO~--P {ANP).
JO
~
24
p..
""
]2
~
~
r-1
~
I
I C'"\
~
18
r-1
~
12
I
0
6
~"'"'
0
24
16
8
0
0
0
0
0.7 1.4 2,1 2.8
-F----.--,--,--...,
<3
~g-at Poa--P/1 {PP)
MPN FC (ANP)
Figure lB.
Figure 17.
Regression of NH 3-N
(ANP) on FC {ANPJ•
Regression of NOj-N
{PP) on Po2--P (PP),
~
~
~
43
.
32
0
~
rl
~
I
~"'"'
+"
aS
24
~ 23
.
16
.5
"
B
u
""'zp..
:;;::
..
9
0
4
•
.,
I
bl)
"'
0
0
4
B
12 16
< 3 +--I:lla.IIJI.-.---.-----.
0
8 12 16
PB {kg X 105)
PB (kg X 105)
Figure 19.
Figure 20,
Regression of NH -N
3
(ANP) on PB.
Regression of FC
(ANP) on PB.
)1
The results of the analyses for the degradation rates
of feces and urine are summarized in Table 2.
The data
have been corrected for the initial nutrient concentrations
present in the sea water before inoculation.
Data have also
been reduced to unity of feces (mg-at/g) and urine (mg-at/ml)
from the diluted concentrations that were actually measured,
The auxiliary experiment on the degradation rate of urea-N
without the presence of feces facilitated the differentiation
of urea-N from total organic-N, and urinary derived NH 3-N
from fecal derived NH -N. Figures 21, 22, and 2) represent
3
respective concentrations of urinary urea-N, urinary NH -N,
3
and fecal Po4--P as r~nctions of time, The concentrations
of f'ecal organic-N, Noj-N, NH 3-N, and NOz-N are not graphically
presented since their functions with time would be represented
by nearly straight lines,
Table 2
Results of Degradation Study
0
urine
mg-at/ml
feces
mg-at/g
NB: -N
3
organic
N
NH)-N
1
4
6
12
24
2.928 2.896 2.868
2.824 2.768 d:0,01
0.032 o.o64 0.092
0.1)6 0,192 ±0,001
0.466 0.454
0,480 0.454 0.474 ±o.o4
0.028 0,029
0.028 0 .0)0 0.029 ±0.002
NOi·N
0
0
0
0
0
· NOz-N
0
0
0
0
0
Po4--P
error
o.o44 o.o49
0.052 0.053 0.054 ±0.0002
32
2.950
(]) 2.900
.:::
•.-l
H
;:I
2. 850
,...;
~ 2.800
zJ
<1l
~
2. 7 50
;:I
+'
<1l
2.700
~ o.osof
o.oool-~.---,,--~,~--,~--~~---.---.---..---..---..--~r-~r---r•
0
2
4
6
8
10 12 14 16 18 20 22 24
hours
Figure 21
Degradation rate of urea-N in sea water.
0.210
(])
0,180
~
0.150
.:::
.,-{
,...;
~ 0.120
zI
f0.090
+'
<1l
0.060
~
s 0.030
0
2
6
8
10
12
14
16
18
20
22
24
hours
Figure 22
NH3-N production from the degradation of urea in sea water.
33
0.054
[JJ
0.052
QJ
(.)
QJ
"--<
0.050
~
0.048
I
I
'i5 0. 046
11<
-:;; 0. 044
I
til
l'l
0.002
0
2
4
6
8
10 12
hours
14
16
18
20
22
24
Figure 23
PO~--P
production from the degradation of feces in sea water.
DISCUSSION
Interpretation of Results
The concentrations of Noj-N, NOz-N• and Po4--P in
the waters of Ano Nuevo and Pigeon Point were similar and
varied only with time and not with locatron (Figures 1), 14,
and 15).
The concentrations of these nutrients were not
significantly correlated with either the pinniped biomass
or the concentrations of NH 3 -N, nor were they related to the
bacteriological data (Table 1). At both Ano Nuevo and Pigeon
point, the concentrations of Noj-N and Po4--P were- significantly correlated to each other (Figures 15 and 16),
In
both cases, the ratios of the concentrations of NOj-N to
Pod--P did not significantly vary from 1511 (Table 1).
This
ratio is comparable to those found in deep water and in
recently upwelled waters (Vaccaro, 196)),
Table J shows a
comparison of the nutrient data obtained in the present
study with similar data commonly obtained from both upwelled
and non-upwelled waters in the northeastern Pacific ocean
(Sverdrup, Johnson, and Fleming, 1942; Harvey, 1966).
The
concentrations of P04- -P, Noj-N, and NOz-N measured at Ano -·
Nuevo and Pigeon Point are consistent with those from other
areas where upwelling is prevalent,
These data indicate,
therefore, that irrespective of subsequent alterations of
nutrient levels by other factors, the surface waters of Ano
35
Nuevo and Pigeon Point are from a similar source, probably
from deep water,
The concentrations of NH -N measured at Ano Nuevo
3
Point were extremely high (Table 3) and were found to be
significantly correlated with the pinniped biomass of Ano
Nuevo Island (Figure 17).
In December, 1970, however, the
concentration of NH -N at ADo Nuevo Point did not correspond
3
to the size of the pinniped populations on the island at that
time (Figure 8),
This anomaly may have been due to the
heavy rains which occurred during that time which could have
washed the residual excreta from the island producing an
effect similar to that of a larger population,
The positive
correlation of NH -N levels with pinniped biomas~, alone,
3
does not prove a ''cause and effect" relationship. However,
the following evidence from the analyses of other data
obtained in this study, gives such a contention strong
support,
Table 3
A comparison of nutrient values from Ailo Nuevo and Pigeon
Point with other areas,
Ranges in Concentration (pg-at/1)
Location
3P04 -P
NOj-N
NOz-N
NH -N
Ano Nuevo Point
0.7-2.2
0.9-14.7
0.1-0.6
2.2-30.2
Pigeon Point
0.5-2.8
1.6-24.4
0,1-0.6
1.8-14.8
Northeastern Pacific
areas without
upwelling
0.1-0.5
0.1-5
0.02-0.2
0.1-2.5
Northeastern Pacific
areas with upwelling
0. 3-4.0
0.5-30
0,1-1.5
0.3-4~0
]6
The laboratory analyses for the degradation rates
of fresh feces and urine of a harbor seal (Phoca vitulina)
have indicated that NHJ-N is a major product from the
degradation of seal excreta.
The levels of organic-N and
NH -N in the feces remained static throughout the 24 hour
3
period,
There was, therefore, no NH -N yield from the degra-
3
dation of organically combined fecal nitrogen,
Similar
studies on the decomposition rates of plankton in sea water
(Grill and Richards, 1964; Foree, Jewell and McCarthy, 1971)
have indicated that a significant decomposition of nitrogenous
material does not occur during the first two weeks,
The percentage of total excretory nitrogen represented in feces is not known for P. vitulina,
fecal nitrogen component of
However, a
].7% has been reported for
Zalophus californianus (Pilson, 1970),
If a similar percentage
is assumed to be valid forE· vitulina, then over
excretory nitrogen is in the urine.
95%
of the
Therefore, the amount
of fecal NHrN is only 0,24% of the total excretory nitrogen.
The analysis of the degradation rate of urinary urea
from P. vitulina revealed a 600% increase of the NHJ-N in 24
hours.
This increase represents the hydrolysis of about
of the total urea-N present in the fresh urine,
5%
Since the sum
of urea-N plus NH -N remained constant during the 24 hour
3
period, the degradation of other nitrogenous compounds in
the urine was negligible,
The sum of urea-N plus NH -N represents an average
3
of
85%
if the total urinary nitrogen for Zalophus californianus
37
(Jackson, Dring and Schroeder, 1939) and for Phoca vitulina
(Smith, 1936),
Therefore, about 82% of the total excretory
nitrogen is urea-Nand NH -N for at least two species of
3
pinnipeds,
Although the production of urea-N varies according
to several factors in each individual (Smith, 1936; Pilson,
1970), it is nevertheless reasonable to assume that the total
urea-N production of a population will be in proportion to
the size of the population,
Therefore, the rate of NH -N
3
production upon the degradation of urinary urea-N lends
strong support to the contention that NH -N concentrations
3
in the water at Ana Nuevo Point are an effect of the nearby
pinniped populations,
The concentrations of Po?--P in the urine were
negligible and consequently omitted from the experiments,
The
fecal poJ--P component,however, was considerable (Table 2)
and increased by 22.7% during the 24 hour period,
The
increase was rapid during the first six hours and much slower
during the remaining 18 hours (Figure 23),
Inorganic phos-
phorus is,therefore,released from fecal material much more
rapidly than is inorganic nitrogen,
These results do not,
however, indicate that POz--P levels in .the water at Allo
Nuevo should have been higher than those measured,
nitrogen is only
If fecal
3.7% of the total excretory nitrogen, and
fecal PoJ--P was less than twice the fecal NH -N after 24
3
hours of degradation, then the ratio of excretory NH -N to
3
PoJ--P is about 10011,
Therefore, during the peak of the
pinniped populations in September, if all the NH -N was of
3
38
pim1iped origin, then the maximum
would have been only 0.3
concentration of
poa--P.
~g-at/1
POd--P of fecal origin
or about 20% of the measured
At the 1.5 ~g-at/1 level, it would
have been impossible to determine the component of fecal
origin.
Another factor which would tend to lower the NH -N
3
to Po4--P ratio even more is the phase difference between
urine and feces.
Urine is a liquid phase that disperses in
the water layer into which it is excreted; so most excretory
nitrogen is limited to the surface waters where it is deposited.
Feces are primarily in the solid phase,
Tourtlette (1969)
found that 84% of a fecal sample of Zalophus californianus
precipitated in standing sea'water in one day.
The water
around Allo Nuevo varies considerably in turbulence, which
consequently could alter the 84% figure,
This does indicate,
however, a fecal distribution that differs from the distribution
of urine.
Since nitrogen is usually a limiting nutrient in
sea water and phosphorusis;not, then NH -N is more rapidly
3
removed than Po4--P (Ryther and Dunstan, 1971). If the water
at Ana Nuevo remained in the vicinity long enough to allow
a substantial removal of NH -N, then Po4--P would tend to
3
be concentrated, This phenomenon was not observed at Ano
Nuevo Point, indicating a constant replacement of the water.
The route of the displaced water is unknown1 Perhaps the
consistently higher PO~--P and occasionally high NH -N con-
3
centrations measured at Pigeon Point are evidences for a
)9
northerly flow of the enriched water from Ano Nuevo,
There
are,however, insufficient data to support this suggestion.
The fecal coliform bacteria counts at Ano Nuevo
Point were also significantly correlated with the pinniped
biomass (Figure 19).
Natural populations of fecal coliform
bacteria grow and reproduce only in the gut of warm-blooded
animals (Geldreich, 1967).
Since the pinnipeds at Ano Nuevo
Island are the only warm-blooded animal,populations in the
vicinity of Ano Nuevo Point, the high fecal coliform counts
can be attributed only to the pinnipeds,
Since the fecal
coliform counts were also significantly correlated with NH -N
3
at Ano Nuevo (Figure 18), a three-way inter-correlation is now
evident, involving pinniped biomass, fecal coliforms, and
NH -N at ADo Nuevo,
3
This interrelationship clearly establishes
the fact that high concentrations of NH -N found in the waters
3
of Ano Nuevo are directly related to the presence of the
pinnipeds,
At Pigeon Point, the NH -N concentrations were also
3
high (Table J),
However, both the NH -N and fecal coliform
3
levels were lower at Pigeon Point than their respective levels
at Ano Nuevo (Figures 3, 8).
Also, neither .NHJ-N nor fecal
coliforms correlated with the pinniped biomass.
These non-
correlations indicate the lack of a direct influence by the
pinnipeds on the NHJ-N and fecal coliform levels at Pigeon
Point.
However, the possibility of an indirect influence can
not be discounted.
Perhaps a northerly longshore current
occurs in the vicinity which could extend the enrichment effect
northward to Pigeon Point; but this is not presently known.
4Q
The other bacteriological data, the total coliform and
feca~
streptococcus counts, did not correlate with
any of the other data.
Coliform bacteria may be from many
sources, only one of which, the gut of warm-blooded animals,
is the source of the fecal coliform group,
Unlike fecal
coliforms, some of the non-fecal members of the coliform
group can reproduce in natural waters; especially where a
nutrient source is readily available (Kittrel and Furfari,
196}).
Therefore, the fecal and non-fecal components of the
total coliform group vary independently from one another,
It was not surprising,then, to find the total coliform data
unrelated to fecal coliform counts and other data,
Fecal
streptococci, however, are fecal-specific in origin and,
like the fecal coliforms, are peculiar to warm-blooded
animals,
Their presence,then, must also be attributed to
the pinniped populations.
Fecal streptococci, however,
survive exposure to sea water for much shorter periods of
time than do fecal or other coliforms1 The LD 50 of fecal
streptococci in sea water is only a few hours (Hanes and
Fragala, 1967; Slantz and Bartley, 195?).
The lack of
correlation between the fecal streptococcus counts and the
pinniped biomass may be due, therefore, to
th~
low survival
rate of these bacteria and the lack of knowledge of the
exact number of pinnipeds on the island at the time of
sampling,
The pinniped biomass consists of monthly averages.
Fecal coliforms survive exposure to sea water long enough,
perhaps, to reflect the average pinniped density •. The result
was a good. correlation of fecal coliforms with pinniped
biomass.
The low survival rate of fecal streptococci in
sea water, however, allowed for the accurate detection of
the presence of pinnipeds for only a few hours prior to
sampling;
The fecal streptococcus counts are, therefore,
poor indicators of the mean monthly·pinniped biomass,
The intended application of the wind stress index
data was to indicate the periods of time during the present
study when upwelling most likely had occurred,
Since
recently upwelled waters have relatively high concentrations
of nutrients (Vaccaro, 1963), the wind stress index, as an
indicator of upwelling, should have correlated with the
nutrient data in the present study,
the case (Table 1),
This, however, was not
Several factors have probably con-
tributed to the non-correlations of these data,
Nutrient
samples were collected once each month, whereas the wind
velocity and wind direction were measured daily and averaged
each month.
Wind velocity fluctuates much more rapidlythan
does current- velocity, This probably causes a considerable
time lag between an increase in wind velocity and any subsequent upwelling that may occur,
Conclusions
The excreta from large populations of pinnipeds
are deposited primarily into the waters around Afio Nuevo
Island.
One of the products from the decomposition of
certain components of the excreta is NH -N.
3
The high
4-2;
concentrations of NH -N found in the water at Afio Nuevo
3
Point are correlated temporally with the biomass of
pinnipeds on the island,
The concentrations of NH 3 -N
in coastal waters normally average 1,0 to J,O pg-at/1 and
thus the high values at Afio Nuevo Point reflect the special
conditions at Afio Nuevo Island related to the pinniped
populations,
Associated with the pinniped excreta are intestinal
bacteria, represented by the fec.al coliform group,
Fecal
coliform bacteria were found in the water at Afio Nuevo
Point in relatively high concentrations which correlated
with
the
3
NH -~
levels and with pinniped biomass, The inter-
relationships of NH -N, fecal coliform bacteria, and the
3
pinniped biomass indicate that the pinnipeds are responsible
for the enrichment of the waters of Afio Nuevo,
A similar direct influence on the water by the
excreta of pinnipeds was not detected at Pigeon Point.
Although NH 3 -N levels at Pigeon Point were high in comparison to normal coastal waters, Pigeon Point NHJ-N and
fecal coliform levels were much lower than the respective
levels ~t Ano Nuevo and did not correlate with pinniped
biomass,
The concentrations of NOj-N, NOz-N, and Po4--P were
found to be indigenous to the water and unrelated to enrichment by pinnipeds,
These nutrient values were comparable to
those found elsewhere in recently upwelled waters, and
differed little between sampling areas,
The 1511 NOj-N to
Poa--P ratio was common to both sampling areas and also
indicates that the waters are of a similar source, probably
from upwelled deeper waters,
Speculations and recommendations for Further Research
The present study is a unique contribution to
science,
The impact of human and other warm-blooded animal
wastes on the coastal marine environment has already been
studied, and there is much literature now available under
the headings of "pollution" and "eutrophication."
However,
these studies have normally been associated with industrial,
domestic, and agricultural wastes, very different from any
corresponding natural processes,
The pinnipeds of Ano Nuevo
Island are only very remotely affected by civilization,
their wastes are introduced unaltered, to the coastal marine
environment.
The influence of pinniped wastes at Ano Nuevo
is undoubtedly much more extensive and complicated than what
has been described by this study,
This speculation is sug-
gested by some anomalous data that were obtained during the
course of this study,
Fecal streptococcus data were unrelated to pinniped
biomass and other data.
Fecal coliform to fecal strepto-
coccus ratios (FC1FS) have been established for waste waters
of several origins,
Waters containing human body wastes are
characterized by FC1FS of 4a1 or higher (Geldreich, Clark,
and Huff, 1964),
Waste waters from stormdrains and stock-
yard discharges have characteristic FC1FS of 0.711 or less
(Geldreich, et. al., 1962; Geldreich, 1966).
The ratios
in this study may be related to pinniped populations, but
have assumed an opposite trend from that characterizing
domestic animals,
the ratio
At the peak of pinniped populations
rose to a high of 14J1 (Appendix E).
The nature
of this relationship is totally unknown and much work needs
to be done on this,
This problem may be associated with
the high die-off rate of fecal streptococci in sea water.
The results of this study are non-quantitative
with respect to the actual degree of enrichment.
The
quantitative determination will require the establishment
of an extensive three dimensional grid, with the distance
between samples reflecting the factors of water movement and
distribution.
The variations in the nutrient concentrations
will reflect the highly variable.current patterns around
Ano Nuevo, the patterns are influenced by wind-induced,
tidal, seasonal, and other variables,
The nutrient levels
will also reflect not only the rates of supply from the
pinniped populations, but in addition, the rates of removal.
Since NH -N is the preferred source of nitrogen for most
3
algae (Syrett, 1962), the half life of NH -N in waters con-
3
taining high standing stocks of plant material may be very
short.
Thus, to understand quantitatively the distribution
of nutrients in an area such as Ana Nuevo, the rates of both
biological and physical processes that remove nutrients must
be understood.
Since the lower intertidal algal crops at
Ano Nuevo are significantly higher than those at Pigeon Point
45
(Hansen, 1971), the concentrations of NH -N that are actually
3
available to the plants may well be significantly higher than
implied in this study by the static measurement of NH -N
3
levels, the benthic algae are probably removing more NH 3-N
from the water at Allo Nuevo than at Pigeon Point,
Probably the greatest problem associated with the
enrichment of sea water at Afio Nuevo concerns the pinniped
excreta directly.
There is very little known of the com-
position of the mixture, the physical and bacteriological
decomposition products, and therefore, the environmental
effects of the decomposition products.
There are perhaps,
then, many unknown factors which may be involved with the . ,.,
natural enrichment of sea water by pinnipeds,
SUMMARY
Extensive populations of pinnipeds haul out on the
rocks and beaches of Ana Nuevo Island,
Behavioral obser-
vations indicate that excreta are deposited into the water
around the island by the pinnipeds,
These observations,
among others have resulted in the formulation of the hypothesis upon which this study is based1 Pinniped excreta
enriches the waters of Ana Nuevo,
From February, 1970, to March, 1971, monthly sea
water samples were collected at Ana Nuevo and Pigeon Point,
the control site.
The samples were analyzed for their
Po4.-
content of NH 3-N, NOj-N, NOz-N,
-P, coliform bacteria,
fecal coliform bacteria, and fecal streptococci. The
resultant data were compared statistically with one another
and with the mean monthly biomass of pinnipeds that frequent
Ana Nuevo Island,
The results of these analyses showed that
fecal coliform bacteria, levels of NH -N, and pinniped
3
biomass are quantitatively related,
This relationship
indicates not only that the waters of Ana Nuevo are enriched,
but also that the enrichment is directly related to the
pinniped excreta,
Results from the analyses for short-term
degradation rates of pinniped feces and urine supported the
field data.
The primary nitrogenous excretory product of
pinnipeds, urea, degrades rapidly in sea water to produce
47
NH -N. Inorganic poa--P was released very rapidly upon
3
the degradation of the fecal sample, The concentration is
very small, however, when compared to the excretory nitrogen.
The other nutrients, Noj-N, N02-N, and most of the
Poz--P are indigenous to the water and not related to
enrichment by pinnipeds.
Comparisons of these nutrient:J
data with data from other areas and a 15:1 Noj-N to Po 43- -P
ratio show that the surface waters in the vicinity of Ano
Nuevo and Pigeon Point have a similar origin, probably
associated with upwelling,
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APPENDIX A
Measurements of NH -N
3
Date of Sample
Concentration
(~g-at/1)
Ano Nuevo Point
22 February 1970
Pigeon Point
2.)4
2.48
4 April 1970
4.6J
2.96
9 May 1970
6.98
5.49
8 June 1970
6.44
7.91
14 July 1970
8.84
12.)0
:.4 August 1970
17.00
9.07
18 September 1970
J0.2J
14.80
11 November 1970
4.57
2.5J
17 December 1970
26.96
3,56
2. 20'
1,81
'8 February 1971
J,68'
6.47
28 March 1971
4,52
J,29
11 January
1971
•
APPENDIX B
Measurements of NOj-N
Date of Sample
Concentration
Afio Nuevo Point
22 February 1970
(P~-at/1)
Pigeon Point
0.86
1.56
4 April 1970
].66
9.79
9 May 1970
~.77
13.58
8 June 1970
6.44
9.45
14 July 1970
0.]7
6.06
6.12
14,96
10,61
15.11
1970
].95
4.10
17 December 1970
7.15
10,)0
11 January 1971
8.59
11.57
6. ]8
16.55
14,67
24,J7
4 August 1970
18 September 1970
11 November
8 February 1971
28 March 1971
APPENDIX C
l•leasurements of N02-N
Concentration (pg-at/1)
Date of Sample
Afio Nuevo Point
Pigeon Point
o.o6
0,09
4 April 1970
0.12
0.22
9 May 1970
0.24
0.24
'8 June 1970
0.]2
o,4J
14 July 1970
0.27
0,24
0.]7
0.]0
18 September 1970
0.24
0.]6
11 November 1970
o.46
o.42
17 December 1970
0 • .54
0 • .57
11 January 1971
O,JJ
0.]7
0.]2
0.28
0.]8
o.4o
22 February 1970
4 August 1970
8 February 1971
28 March 1971
APPENDIX D
Measurments of PO~--P
Concentration (pg-at/1)
Date of Sample
Afio Nuevo Point;
Pigeon Point
0.67
0.46
4 Aprll 1970.
0.97
1.47
9 May 1970
0,90
1.80
8 June 1970
1.28
1.24
14 July 1970
0.68
2.18
1.01
1,66
18 September 1970
1.4)
1.97
11 November
1.2)
l.JJ
17 December 1970
2.24
2,81
11 January 1971
1,21
1.45
1,24
1,69
1,69
1,96
22 February 1970
4 August 1970
8 February 1971
28 March 1971
APPENDIX E
Bacteriological Data
Date of Satn];!le
22 February 1970
4 April 1970
location
<0.4J
<0.33
7
9
ANP
ANP
PP
<3
<3
<3
<J
<}
<}
<3
<}
<3
<}
<3
<3
1
1
1
1
ANP
ANP
9
<3
<J
<3
9
<3
<J
<J
<3
<3
>3,00
1
>0.13
1
<:J
2]
ANP
ANP
PP
J
4
<3
<3
3
4
<J
<}
<J
<}
<3
<J
>1,00
>L3J
1
1
ANP
ANP
<J
<J
<3
7
<J
<3
<}
4
<3
<3
<J
<3
1
1
1
>1.33
ANP
ANP
<J
<}
<3
<J
<}
1
>5.00
1
1
>14.JJ
>1,JJ
1.00
pp
pp
4 August 1970
FCIFS
<J
<3
pp
14 July 1970
MPN-FS
7
4}
pp
pp
pp
8 June 1970
MPN-FC
ANP
pp
9 May 1970
MPN-TC
pp
pp
<J
<J
<J
i5
<3
<J
19 September 1970
ANP
PP
PP
4)
4
9
4)
4
9
<J
<J
9
18 December 1970
ANP
ANP
9
23
150
4
4
<J
<3
27
4}
7
0' 15
<0,07
<0.4J
<J
.4
4J
<J
4
4
<J
21
4
<0.14
1
0.09
0,07
pp
PP
11 January 1971
ANP
ANP
pp
pp
;1:5
75
2]
6
4}
4J
0.65
,'
APPENDIX F
Mean Pinniped Biomass
Mean
Numbers o:f
Pinnipeds
Month
Mean
Pinniped
Biomass
495,520kg
February
1970
863
March
1970
1 '417
436,360
April
1970
1, 652
461,610
May
1970
2,510
533.330
June
1970
1,877
561,850
July
1970
2,460
663,490
August
1970
5,291
1,228,540
September
1970
7,380
1' 540, 900'
October
1970
3. 604
953.590
November
1970
4,023
741,440
December
1970
2,456
488,040
January
1971
1, 369
606,460
February
1971
865
495,780
March
1971
1t/;90
460,620