Invertivore MeHg exposure and sensitivity: Past assumptions, current - - PowerPoint PPT Presentation

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

David Evers, Melissa David Evers, Melissa Duron Duron, , Oksana Oksana Lane BioDiversity Research Institute Lane BioDiversity Research Institute Dan Dan Cristol Cristol, College of William and Mary , College of William and Mary John John Schmerfeld Schmerfeld, U.S. Fish and Wildlife Service , U.S. Fish and Wildlife Service Bart Hoskins, U.S. Environmental Protection Agency Bart Hoskins, U.S. Environmental Protection Agency Robert Taylor, Texas A&M University Robert Taylor, Texas A&M University

Mercury Mercury – – no longer just a fish issue no 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 availability Where is the production and availability

• f MeHg greatest?
• f 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

Wetlands Wetlands – – MeHg factories MeHg factories

What species are at greatest risk? What species are at greatest risk? Piscivores …… Piscivores …… Invertivores …… Invertivores …… Others? Others?

Different stories Different stories told by different… told by different… Species Species Habitats Habitats Foraging guilds Foraging guilds Geographic areas Geographic areas

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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

Chicks fledged / Territoril pair

0.00 0.20 0.40 0.60 y = -0.0294x + 0.4802 r2 = 0.86

Common Loon Common Loon – – reproductive effects now shown in New reproductive effects now shown in New England and eastern Canada England 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 Loon Common Loon – – reproductive effects are also apparent reproductive effects are also apparent in New York State in 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) Average # Chicks Fledged Annually/Adult Loon

Predicted blood Hg (ug/g, ww) 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)

0.2 0.4 0.6 0.8 1 1.2 1.4 Egg Hg (ug/g, ww) 1

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

.6

Different stories Different stories told by different… told by different… Species Species Habitats Habitats Foraging guilds Foraging guilds Geographic areas Geographic areas

Some invertivores are 3 Some invertivores are 3-

• 4x > > piscivores

4x > > piscivores

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

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

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 Hg Spiders 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 habitats Recommended 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

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Mean Fur Hg Concentrations 10 20 30 40 50 60 70 *Bat (n=16) **Mink (n=92) **Otter (n=69) Hg (ppm)yxvutsrponmlkihgfedcaTSRPONMLIHGFECBA

Indiana Bat

Nocturnal invertivores Nocturnal invertivores – – bats are likely impacted by Hg as well bats 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 total 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 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 by Is biological diversity being impacted by Hg and other air pollutants? Hg and other air pollutants?

Yes Yes

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

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

• USEPA

USEPA-

• sponsored plan recently

sponsored plan recently constructed by external scientists constructed by external scientists

• Provides a blueprint for tracking

Provides a blueprint for tracking spatial and temporal Hg trends spatial and temporal Hg trends

• Two publications

Two publications

• ES&T paper

ES&T paper

• SETAC publication “

SETAC publication “Monitoring Monitoring the response to changing mercury the response to changing mercury deposition deposition” ”

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

Demonstration of rapid recovery in biotic Hg levels in New Hamps Demonstration of rapid recovery in biotic Hg levels in New Hampshire hire

• 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

Adult Common Loon Blood Hg Equivalent (ug/g, ww)

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

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

Senate bill co Senate bill co-

• sponsored by Collins, Clinton and Lieberman

sponsored by Collins, Clinton and Lieberman House bill co House bill co sponsored by Allen and Walsh sponsored 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
• n ______________

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 rapidly Timing 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 by From a deposition model developed by Ashu Dastoor Ashu Dastoor, Environment Canada , Environment Canada

Thanks Thanks to…. to….

• New York State Energy Research and Development

New York State Energy Research and Development Authority Authority

• New York Department of Environmental

New York Department of Environmental Conservation Conservation

• The Nature Conservancy

The Nature Conservancy