Invertivore MeHg exposure and sensitivity:Invertivore MeHg exposure and sensitivity: Past assumptions, current findingsPast assumptions, current findings

David Evers, MelissaDavid Evers, Melissa DuronDuron,, OksanaOksana Lane BioDiversity Research InstituteLane BioDiversity Research Institute DanDan CristolCristol, College of William and Mary, College of William and Mary JohnJohn SchmerfeldSchmerfeld, U.S. Fish and Wildlife Service, U.S. Fish and Wildlife Service Bart Hoskins, U.S. Environmental Protection AgencyBart Hoskins, U.S. Environmental Protection Agency Robert Taylor, Texas A&M UniversityRobert Taylor, Texas A&M University

MercuryMercury –– no longer just a fish issueno longer just a fish issue

•• Where is the availability of MeHg greatest?Where is the availability of MeHg greatest?

•• What species are at greatest risk?What species are at greatest risk?

•• Is biological diversity being impacted?Is biological diversity being impacted?

•• How can we track spatial and temporal trends?How can we track spatial and temporal trends?

Where is the production and availabilityWhere is the production and availability of MeHg greatest?of MeHg greatest?

Total Hg deposition estimated using ISCST3 for 2002 (USEPA 1995)

Biological Hg hotspots (based on freshwater piscivores)Biological Hg hotspots (based on freshwater piscivores)

Summary

•Perch-loon based

•5 hotspots

•Area = 22,500 km2

•10 areas of concern

•Sig. finding as the premise of the current US EPA Cap-and-Trade Rule is that hotspots can not be created

Evers et al., 2007 BioScience 56:29-43

WetlandsWetlands –– MeHg factoriesMeHg factories

What species are at greatest risk?What species are at greatest risk?

Piscivores ……Piscivores ……

Invertivores ……Invertivores ……

Others?Others?

Different storiesDifferent stories told by different…told by different…

SpeciesSpecies

HabitatsHabitats

Foraging guildsForaging guilds

Geographic areasGeographic areas

Female Loon Unit (FLU) equivalent (ug/g, ww)

0.1 -0 .5 0.5 -1 .0 1.0 -1 .5 1.5 - 2.0 2.0 -2 .5 2.5 -3 .0 3.0 -3 .5 >3.5

Chi

cks

fledg

ed /

Terr

itoril

pai

r

0.00

0.20

0.40

0.60

y = -0.0294x + 0.4802 r2 = 0.86

Common LoonCommon Loon –– reproductive effects now shown in Newreproductive effects now shown in New England and eastern CanadaEngland and eastern Canada

A. Recent findings from a 10-year study indicate sig. relationship between increasing Hg levels and:

1. Physiological changes 2. Abnormal behavior 3. Survival 4. Reproductive success

B. Some areas of the Northeast contain population sinks because of Hg

Evers et al., In Press, Ecotoxicology; Burgess and Meyer, In Press, Ecotoxicology

LOAELs Blood = 3.0 ppm (ww) Feather = 40 ppm (fw) Egg = 1.3 ppm (ww)

Common LoonCommon Loon –– reproductive effects are also apparentreproductive effects are also apparent in New York Statein New York State

A. Based on a long-term monitoring effort by N. Schoch et al.

B. Analysis based on quartile regression models

C. Pattern of loon productivity and Hg levels in New York is very similar to Burgess and Meyer (In press), where they found 50% fewer young were produced at 3.45 ppm (ww)

Avg # Chicks Fledged vs. Adult Loon Hg (ppm)

0.0

0.5

1.0

1.5

2.0

2.5

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

Average Adult Loon Hg (ppm)

Ave

rage

# C

hick

s Fle

dged

A

nnua

lly/A

dult

Loo

n

Pred

icte

d bl

ood

Hg

(ug/

g, w

w)

3.50

3.00

2.50

2.00

1.50

1.00

0.50

0.00

LOAEL for Ring-necked Pheasant = 0.20 ppm

LOAEL for Mallard = 0.80 ppm (overall)

Cause of concern for Common Grackle = 0.40 ppm

LOAEL for Common Loon = 1.30 ppm

y = 2.1115x + 0.1118

r2 = 0.5034

LOAEL for Mallard = 1.0 ppm (neurological)

0 0.2 0.4 0.6 0.8 1 1.2 1.4

Egg Hg (ug/g, ww)

1

Relationship between egg and predicted blood Hg levelsRelationship between egg and predicted blood Hg levels

.6

Different storiesDifferent stories told by different…told by different…

SpeciesSpecies

HabitatsHabitats

Foraging guildsForaging guilds

Geographic areasGeographic areas

Some invertivores are 3Some invertivores are 3--4x >> piscivores4x >> piscivores

0

1

2

3

4

5

6

7

8

9

Belted Kingfisher (n=7)

Red-winged Blackbird (n=11)

Belted Kingfisher (n=13)

Carolina Wren (n=12)

Sudbury R., MA

Holston R., VA

Aquatic versus terrestrial: South River only

Same species Same samples sizes Reference sites

Mercury is not just accumulating in aquatic-feeding birds

How can this be? …….Spiders are the key linkHow can this be? …….Spiders are the key link

0 50 100 150

Trout (17)

Other Fish (41)

Riparian Spiders (23)

Aquatic Invertebrate Predators (28)

Amphibians (13)

Terrestrial Invertebrate Predators (5)

Aquatic Invertebrate Detritivores (63)

Terrestrial Invertebrate Herbivores (7)

Taxonomic/Trophic Group Mercury concentration (ng/g)

Total Mercury Methyl Mercury

Data from Jeff Loukmas, NYDEC

Spiders are responsible for 74% of HgSpiders are responsible for 74% of Hg in the Carolina Wren (n=206 prey items from nestlings)in the Carolina Wren (n=206 prey items from nestlings)

Recommended songbird indicators of New York habitatsRecommended songbird indicators of New York habitats

River Floodplains - Louisiana Waterthrush

Estuaries - Saltmarsh Sharp-tailed Sparrow

Sphagnum bogs – Palm Warbler

Beaver pond wetlands - Rusty Blackbird

Montane areas – Bicknell’s Thrush

Northern Hardwoods – Wood Thrush

Emergent Wetlands – Red-winged Blackbird

Scrub-shrub/forested Wetlands – Carolina Wren

Mean Fur Hg Concentrations

0

10

20

30

40

50

60

70

*Bat (n=16) **Mink (n=92) **Otter (n=69)

Hg

(ppm

)

Indiana Bat

Nocturnal invertivoresNocturnal invertivores –– bats are likely impacted by Hg as wellbats are likely impacted by Hg as well

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

450.0

500.0

Hoary Bat Red Bat Northern Long-eared Bat Eastern Pipestrelle Little Brown Bat

Fur t

otal

Hg

(ug/

g, fw

)

Highest bat fur Hg level in a study at Great Smokey Mtn. NP was ~ 10 ppm

Adverse effects threshold 20.0 ug/g**

Mortality threshold 47.0 ug/g**

M ean Fur Hg Concentrations

0

10

20

30

40

50

60

70

*Bat (n=16) **Mink (n=92) **Otter (n=69)

Hg

(ppm

)

Indiana Bat

Maine Maine

Is biological diversity being impacted byIs biological diversity being impacted by Hg and other air pollutants?Hg and other air pollutants?

YesYes

How can we track spatial and temporalHow can we track spatial and temporal trendstrends

New standardized approach:New standardized approach: National Mercury Monitoring PlanNational Mercury Monitoring Plan

•• USEPAUSEPA--sponsored plan recentlysponsored plan recently constructed by external scientistsconstructed by external scientists

••Provides a blueprint for trackingProvides a blueprint for tracking spatial and temporal Hg trendsspatial and temporal Hg trends

•• Two publicationsTwo publications ••ES&T paperES&T paper ••SETAC publication “SETAC publication “MonitoringMonitoring the response to changing mercurythe response to changing mercury depositiondeposition””

Mason et al., 2005, 39(1):14A-22A

Demonstration of rapid recovery in biotic Hg levels in New HampsDemonstration of rapid recovery in biotic Hg levels in New Hampshirehire

•Area water chemistry and watershed variables do not indicate > normal methylation (i.e., area similar to control)

•Based on 52 individuals on 10 lakes

•3 ppm (ww) is LOAEL

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

1998 1999 2000 2001 2002 2003 2004 2005 2006

Adul

t Com

mon

Loo

n Bl

ood

Hg

Equi

vale

nt (u

g/g,

ww

)

~7,000 lbs of Hg ~6,600 lbs of Hg ?? emitted w/n 100 removed locally miles upwind from 1999-2001

Legislative Bill for national Hg monitoring introducedLegislative Bill for national Hg monitoring introduced in March 2007in March 2007

Senate bill coSenate bill co--sponsored by Collins, Clinton and Liebermansponsored by Collins, Clinton and Lieberman House bill coHouse bill co sponsored by Allen and Walshsponsored by Allen and Walsh --

To provide for the establishment of a national mercury monitoring program.

IN THE HOUSE OF REPRESENTATIVES

Mr. ALLEN introduced the following bill; which was referred to the Committee on ______________

A BILL To provide for the establishment of a national mercury

monitoring program.

Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled

SECTION 1. SHORT TITLE

This Act may be cited as the ‘‘Comprehensive National Mercury Monitoring Program Establishment Act’’

Timing is everything…..the global Hg scene is rapidlyTiming is everything…..the global Hg scene is rapidly changing and we are all connected.changing and we are all connected.

From a deposition model developed byFrom a deposition model developed by Ashu DastoorAshu Dastoor, Environment Canada, Environment Canada

ThanksThanks to….to….

•• New York State Energy Research and DevelopmentNew York State Energy Research and Development AuthorityAuthority

•• New York Department of EnvironmentalNew York Department of Environmental ConservationConservation

••The Nature ConservancyThe Nature Conservancy