Harmful Algal Blooms and Microcystin in the
Tidal Fresh James River,
Joe Wood, Ph.D. - Chesapeake Bay Foundation
*Research performed while at VCU
Chesapeake Bay Foundation
Largest non-profit working to “Save the Bay”
Offices in Virginia, Maryland, and Pennsylvania
205,000 members (78,000 in Virginia)
Focus on education, advocacy, restoration, and
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Introduction
Talk Outline
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Background on the tidal fresh James River
What is Microcystin?
Effects on Aquatic Life
Do Micrcoystin levels correspond to Chlorophyll
levels?
The Tidal Fresh James River
Study Site
Data: Average of monthly values from 2005-2010
(DEQ~ Chesapeake Bay Program)
Algal Blooms in the Tidal Fresh James
Persistent blooms
occur in the
region where the
James transitions
from a narrow,
deep channel to a
wide shallow
channel.
Sampling locations for VCU weekly
monitoring (2010-present).
Shallow areas
provide more
favorable light
conditions which
enhance algal
growth.
What is Microcystin?
• Hepatotoxin (liver)
produced by several
cyanobacteria
(photosynthetic bacteria)
• Potential grazer
deterrent
• Increased Probability of
Detection in Eutrophic
Systems (Poste et al.
2011, Heisler et al.)
Microcystin
Protective Standards:
-1.
World Health Organization (WHO) Drinking
water
1
µg
L
Poste et al 2011
Virginia recreational Waterbody Closure: 6 µg L-1
WHO Consumption standard .04 µg MC kg human-1
Negative Impacts of Microcystin
Increased
Apoptic Cell
death, Tumors
and Liver
Cancer in Trout
(Fischer et al
2011)
Mortality and
Hematological
Lesions in
Flamingos
(Miller et al
2010)
Mortality, Liver
Hemorrhaging
and tumor
formation in Sea
Otters, (Miller et
al 2010)
2012
Lake Erie
2014: Toledo
Water Supply
severely
impacted
c
20,000
CHLa and cyanotoxins
in
the
James
Cyanobacteria
River during 2011.
0
31-May
21-Jun
12-Jul
2-Aug
23-Aug
13-Sep
100
8
CHLa (ug/L)
80
6
60
CHLa
4
Microcystin
2
40
20
0
10-May
0
9-Jun
9-Jul
8-Aug
7-Sep
CHLa and cyanotoxins in the James River during 2011.
*treated water
Microcystin (ug/L)
10-May
Contact
standard
(WHO)
Drinking
standard*
(WHO)
Microcystin assimilated by fish and crabs and
persists at lower concentrations
DEQ concludes human exposure via consumption is
unlikely in this system
Fish who consume algae-rich diets are
more vulnerable to toxin exposure
Algal Toxins to Riparian Food Webs
Microcystin is
found in aquatic
insects including
mayflies.
When insects
emerge and are
consumed, the
toxin is transferred
to birds and
spiders.
L. Bulluck, N. Moy and P. Bukaveckas. VCU.
Microcystin influences on Clams
With Clams
Without Clams
0.04
0.02
0
1
2
Microcystin (µg L-1 )
3
4
100%
40
N Obs
> 0.4 µg L-1
> 0.8
75%
30
> 1.6
> 3.2
50%
20
25%
10
0%
0
0-10
10-20
20-30
30-40 40-50
CHLa (µg L-1)
50-60
60-70
70-80
Observations
Bottom: likelihood of
exceeding Microcystin
concentrations at
various levels of
CHLa.
R² = 0.94
CR50 = 0.40 µg L-1
0.00
Probability of exceedence
Top: effects of
exposure to dissolved
Microcystin on
clearance rates of
Rangia.
Clearance rate (L g DW -1 h-1)
Cyanotoxin Effects
on Benthic Filterfeeders
0.06
Microcystin Impairments occur more
frequently at Higher Chlorophyll Levels
Current Summer Standard
(23 µg L-1)
Conclusions
• Microcystin occurs regularly in the
tidal fresh James and accumulates in
invertebrates, fish and birds
• Bivalve Grazing rates are constrained
by Microcystin
• Microcystin occurs much more
frequently at levels above the current
CHLa standard
Questions?
Funding provided by VA DEQ and City of
Richmond Department of Public Utilities