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 Duron , Oksana Oksana Lane BioDiversity Research Institute Lane BioDiversity Research Institute David Evers, Melissa Duron, Dan Cristol , College of William and Mary Dan Cristol, College of William and Mary John Schmerfeld , U.S. Fish and Wildlife Service John Schmerfeld, 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 – – no longer just a fish issue no longer just a fish issue Mercury • 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 of MeHg greatest? of MeHg greatest?

Biological Hg hotspots (based on freshwater piscivores) Biological Hg hotspots (based on freshwater piscivores) Summary •Perch-loon based •5 hotspots •Area = 22,500 km 2 •10 areas of concern Total Hg deposition estimated using ISCST3 for 2002 (USEPA •Sig. finding as the 1995) 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 – – MeHg factories MeHg factories Wetlands

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

Common Loon – – reproductive effects now shown in New reproductive effects now shown in New Common Loon England and eastern Canada England and eastern Canada A. Recent findings from a 10- year study indicate sig. 0.60 relationship between Chicks fledged / Territoril pair increasing Hg levels and: 0.40 1. Physiological changes 2. Abnormal behavior zyxwvutsrqponmlkjihgfedcbaYWUTSRPONMLJIHGFEDCBA 3. Survival 0.20 4. Reproductive success y = -0.0294x + 0.4802 r2 = 0.86 0.00 B. Some areas of the 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 Female Loon Unit (FLU) equivalent (ug/g, ww) Northeast contain population LOAELs sinks because of Hg Blood = 3.0 ppm (ww) Feather = 40 ppm (fw) Egg = 1.3 ppm (ww) Evers et al., In Press , Ecotoxicology; Burgess and Meyer, In Press , Ecotoxicology

Common Loon – – reproductive effects are also apparent reproductive effects are also apparent Common Loon in New York State in New York State A. Based on a long-term Avg # Chicks Fledged vs. Adult Loon Hg (ppm) monitoring effort by N. Schoch et al. 2.5 Average # Chicks Fledged Annually/Adult Loon 2.0 B. Analysis based on quartile regression models 1.5 C. Pattern of loon 1.0 productivity and Hg levels in New York is very similar 0.5 to Burgess and Meyer (In 0.0 press), where they found 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 50% fewer young were Average Adult Loon Hg (ppm) produced at 3.45 ppm (ww)

Relationship between egg and predicted blood Hg levels Relationship between egg and predicted blood Hg levels 3.50 LOAEL for Common Loon = 1.30 ppm Predicted blood Hg (ug/g, ww) 3.00 2.50 LOAEL for Mallard = 1.0 ppm (neurological) 2.00 LOAEL for Mallard = 0.80 ppm (overall) 1.50 1.00 Cause of concern for Common Grackle = 0.40 ppm 0.50 y = 2.1115x + 0.1118 LOAEL for Ring-necked Pheasant = 0.20 ppm r 2 = 0.5034 0.00 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1 .6 Egg Hg (ug/g, ww)

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- -4x > > piscivores 4x > > piscivores Some invertivores are 3 9 8 7 Sudbury R., MA 6 Holston R., VA 5 4 3 2 1 0 Belted Kingfisher Red-winged Belted Kingfisher Carolina Wren (n=7) Blackbird (n=11) (n=13) (n=12)

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 link How can this be? …….Spiders are the key link Terrestrial Invertebrate Total Mercury Herbivores (7) Methyl Mercury Aquatic Invertebrate Detritivores (63) Terrestrial Invertebrate Predators (5) Amphibians (13) yxwutsrqponmljihgfedcbaTPMHGFE Aquatic Invertebrate Predators (28) Riparian Spiders (23) Other Fish (41) Trout (17) 0 50 100 150 Taxonomic/Trophic Group Mercury concentration (ng/g) 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

Hg (ppm) yxvutsrponmlkihgfedcaTSRPONMLIHGFECBA zyxwvutsrqponmlkjihgfedcbaYWUTSRPONMLJIHGFEDCBA Nocturnal invertivores – – bats are likely impacted by Hg as well bats are likely impacted by Hg as well Nocturnal invertivores 500.0 ywvutsrponmlkihgfedcbaVUTSRPONMLIHFECBA 450.0 400.0 350.0 Fur total Hg (ug/g, fw) 300.0 Highest bat fur Hg level in a study at 250.0 Great Smokey Mtn. NP was ~ 10 ppm 200.0 150.0 100.0 yxwutsrqponmljihgfedcbaTPMHGFE 50.0 0.0 Hoary Bat Red Bat Northern Long-eared Bat Eastern Pipestrelle Little Brown Bat M ean Fur Hg Concentrations Mean Fur Hg Concentrations 70 70 Indiana Bat Indiana Bat 60 60 50 50 Hg (ppm) Mortality threshold 47.0 ug/g** 40 40 30 30 Adverse effects threshold 20.0 20 20 ug/g** Maine Maine 10 10 0 0 *Bat (n=16) *Bat (n=16) **Mink (n=92) **Mink (n=92) **Otter (n=69) **Otter (n=69)

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 “ Monitoring SETAC publication “ Monitoring the response to changing mercury the response to changing mercury Mason et al., 2005, 39(1):14A-22A deposition ” deposition ”

Demonstration of rapid recovery in biotic Hg levels in New Hampshire hire Demonstration of rapid recovery in biotic Hg levels in New Hamps 7.00 Adult Common Loon Blood Hg Equivalent (ug/g, ww) 6.00 5.00 4.00 3.00 2.00 •Area water chemistry and 1.00 watershed variables do not indicate 0.00 > normal methylation (i.e., area 1998 1999 2000 2001 2002 2003 2004 2005 2006 similar to control) •Based on 52 individuals on 10 lakes •3 ppm (ww) is LOAEL ~ 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 introduced Legislative Bill for national Hg monitoring introduced in March 2007 in March 2007 Senate bill co- -sponsored by Collins, Clinton and Lieberman sponsored by Collins, Clinton and Lieberman Senate bill co House bill co sponsored by Allen and Walsh - sponsored by Allen and Walsh House bill co - To provide for the establishment of a national mercury monitoring program. zyxwvutsrqponmlkihgfedcbaWVUTSRPONMLKIHFEDCBA IN THE HOUSE OF REPRESENTATIVES Mr. A LLEN 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 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 Ashu Dastoor Ashu Dastoor, Environment Canada , Environment Canada From a deposition model developed by