Harmful Algal Blooms and Microcystin in the Tidal Fresh James

River, Joe Wood, Ph.D. - Chesapeake Bay

Foundation

*Research performed while at VCU

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 litigation

Chesapeake Bay Foundation

Introduction

Talk Outline

• 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

Data: Average of monthly values from 2005-2010 (DEQ~ Chesapeake Bay

Program)

Study Site

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.

Shallow areas provide more favorable light conditions which enhance algal growth.

Sampling locations for VCU weekly monitoring (2010-present).

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.)

Poste et al 2011

Protective Standards:World Health Organization (WHO) Drinking

water 1 µg L-1.Virginia recreational Waterbody Closure: 6 µg L-

1WHO Consumption standard .04 µg MC kg

human-1

Microcystin

Negative Impacts of MicrocystinIncreased

Apoptic Cell death,

Tumors and Liver

Cancer in Trout

(Fischer et al 2011)Mortality,

Liver Hemorrhaging and tumor formation in Sea Otters, (Miller et al

2010)

Mortality and

Hematological Lesions

in Flamingos

(Miller et al 2010)

Lake Erie2014: Toledo Water Supply

severely impacted

2012

CHLa and cyanotoxins in the James River during 2011.0

20,000

40,000

60,000

10-May 31-May 21-Jun 12-Jul 2-Aug 23-Aug 13-Sep

0

20

40

60

80

100

10-May 9-Jun 9-Jul 8-Aug 7-Sep

CHLa

(ug/

L)

0

2

4

6

8

Mic

rocy

stin

(ug/

L)

CHLa

MicrocystinDrinking standard*(WHO)

Contact standard(WHO)

CHLa and cyanotoxins in the James River during 2011.

*treated water

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

L. Bulluck, N. Moy and P. Bukaveckas. VCU.

Microcystin is found in aquatic insects including mayflies.

When insects emerge and are consumed, the toxin is transferred to birds and spiders.

Microcystin influences on Clams

With Clams

Without Clams

R² = 0.94

CR50 = 0.40 µg L-1

0.00

0.02

0.04

0.06

0 1 2 3 4

Microcystin (µg L-1)

Cle

aran

ce r

ate

(L g

DW

-1 h

-1)Cyanotoxin Effects

on Benthic Filter-feeders

Top: effects of exposure to dissolved Microcystin on clearance rates of Rangia.

Bottom: likelihood of exceeding Microcystin concentrations at various levels of CHLa.

0%

25%

50%

75%

100%

0-10 10-20 20-30 30-40 40-50 50-60 60-70 70-80CHLa (µg L-1)

Pro

babi

lity

of e

xcee

denc

e

0

10

20

30

40

Obs

erva

tions

N Obs

> 0.4 µg L-1

> 0.8

> 1.6

> 3.2

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

Funding provided by VA DEQ and City of Richmond Department of Public Utilities

Questions?