# Presentation: 338870

## Mercury, Mercury Everywhere!  What’s a critter to eat?  Development of a mercury Wildlife Criterion for Maine 

**David Evers and Oksana Lane, **
**BioDiversity Research  Institute**
**&**
**Barry Mower, **
**Maine Department of Env. Protection**
**&**
**Robert Taylor,**
**Texas A&M Trace Element Res. Lab**
**&**
**Robert Poppenga**
**University of Penn., Animal Health Diagnostics Lab**

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## Presentation Outline

- Risk Assessment Approach for developing a Wildlife Criterion Value (WCV) for Hg
- Defining parameters
- Using the Common Loon as an initial standard
- Why use the loon?
- 3.  	Risk Characterization (weight of evidence approach)
- Exposure profile results (spatially explicit)
- Hazard profile results (individual & population level)
- WCV Hg Model
- Preliminary results

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## What is a WCV

- A procedure to estimate surface Hg water concentrations that will protect the viability of *wildlife populations* associated with aquatic resources
- First developed and used in 1995 for the Great Lakes Water Quality Initiative (GLI)
- An independently directed U.S. Congressional  request in 1990 for a WCV (as mandated by the Clean Air Act) was developed by the U.S. EPA in a 1997 Report to Congress.
- Parts of this report were published by Nichols and Bradbury as “Derivations of wildlife values for mercury” in the J. Toxicology and Environ. Health, 1999.

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## Why use the Common Loon as our initial standard

- Documented individual and, potentially, population level impacts from MeHg ingestion;
- High trophic level obligate piscivore (biomagnification);
- “K-selected” life history strategy (bioaccumulation);
- Complex and coordinated behaviors within pair;
- Moderate to high sensitivity to stressors;
- Logistically feasible (easily observed and individually identified over entire breeding period);
- Some matrices (i.e., blood and eggs) represent a target area (i.e., a lake);
- High profile to public and therefore policymakers;
- Demographic models based on >3,000 banded loons.

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## Slide 5

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## Test Dose

- EPA WCV limitations
- Test dose is:
- Based on mallards, non-piscivorous birds that are more sensitive to Hg toxicity because of evolutionary reasons;
- Based on laboratory studies;
- Based on impacts to individuals.
- Ingestion rates and BAF are quite generic and are not based on empirical data.
- BRI WCV for Maine (response to limitations in EPA model)
- Test dose is:
- based on a species that is sensitive to Hg toxicity and is exposed to Hg levels that are significantly higher than historical levels on freshwater lakes;
- Based on in-field studies:
- Based on impacts to populations.
- Ingestion rates and BAF are empirically measured parameters.

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## Developing an Exposure Profile

- Matrix type and meaning:
- _Blood_: reflects current dietary uptake (based on strong relationship between breeding adult blood Hg and fish prey Hg collected from the same lake).
- _Feather_: reflects body burden and if input > output will show increase of MeHg related to age.
- _Egg_: reflects primarily breeding lake dietary uptake (i.e., 79% of the egg Hg can be explained by female blood Hg)*
- Results of effort:
- Adults sampled: >1,800
- Juveniles sampled: >1,400
- Eggs sampled: >900
- * Evers et al. 2003.  Common Loon eggs as indicators of methylmercury availability in North America.  Ecotoxicology 12:69-81.

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## Geographic Context:  Sampling from 1989-2002

**Geographic Context:  Sampling from 1989-2002**

**Kenai NWR**

**Kejimkujik NP**

**Florida**

**North Slope**

**Tetlin NWR**

**Mat-Su Valley**

**Northwest**

**Voyageurs NP**

**Grand Rapids Area**

**Isle Royale NP**

**North-cent. WI**

**Seney NWR**

**Ottawa NF**

**Lepreau area**

**Rangeley Lakes**

**La Maurice NP**

**Chesapeake Bay**

**Walker Lake**

**Tomalas Bay**

**KEY FOR STUDY SITES**
**               ****Breeding**** **
**               ****Winter**
**               ****Migration**

**Pinchi Lake area**

**Adirondacks**

**Topaz Lake**

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## Geographic context for MeHg availability 		

- Significant increase from western to eastern North America*
- New England has some of the highest levels of MeHg availability

- Between

- Within

- * Evers et al. 1998.  Geographic trend in mercury measured in Common Loon feathers and blood.  Environ. Tox. Chem. 17:173-183.

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## Lakes With Representative Loon Tissue Hg Levels (N>400 terr, >250 Lakes)

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## Rangeley Lakes Focal Study Site (44 lakes with 181 Loon Territories)

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## Hazard Assessment for individuals;  Does Hg impact individual loons? YES

- Physiological:
- Significant relationship with increasing corticosterone stress hormones & MeHg levels
- Behavioral (>2,500 hours of observation)
- Higher Hg levels sig. reduce time incubating
- Higher Hg levels cause adults to become lethargic (i.e., they spend sig. more time in low energy behaviors)
- Pharmacokinetics:
- Recaptured adults have 9% (males) and 5.6% (females) annual increase in feather Hg levels
- Recaptured juveniles have increasing (1-3%/day) Hg levels during the summer

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## Behavioral impacts

- R

- 2

-  = 0.230

- p = 0.037

- 0%

- 10%

- 20%

- 30%

- 40%

- 50%

- 60%

- 70%

- 80%

- 90%

- 0.00

- 1.00

- 2.00

- 3.00

- 4.00

- 5.00

- 6.00

- 7.00

-  Blood Hg (ppm, ww)

- Percent time adults (M&F) spent

-  in High* energybehaviors

- Low Hg incubation time=99% of time
- High Hg incubation time=85% of time

- Male foraging time for
- high Hg risk loons
-  is one-third that of
- low Hg risk ones

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## Population-level impacts from Hg; Is Hg harming loon populations? Likely

- Condition/Fitness:
- Measurements indicate a decline related to increasing Hg levels.
- Flight feather asymmetry is significant in Maine’s breeding population – the 3.5% mean may result in 15% less flight efficiency
- Recaptured high/xhigh adults show a sig. (p=0.03) body weight decline vs. low/mod (n=21).
- Egg weights have a sig. (p=0.02) decline as Hg levels increase
- Reproductive Success:
- -   Compared to low risk loon pairs, high risk pairs;
- Significantly initiate 7% fewer nests
- Significantly hatch 31% fewer eggs
- Significantly fledge 40% fewer young

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## Impacts to reproductive success

**0.76**

**1.22**

**0.74**

**0.68**

**0.76**

**0.99**

**0.65**

**0.49**

**0.71**

**0.84**

**0.68**

**0.41**

- 0

- 0.2

- 0.4

- 0.6

- 0.8

- 1.0

- 1.2

- 1.4

- Nest (NP/TP)

- Hatch (SY/NP)

- Chick Survival (LY/SY)

- Overall Productivity (LY/TP)

**Productivity Parameters**

**Loon Productivity Rates**

- Low Risk (n=30 territories, 149 territory-years )

- Moderate Risk (n=58 territories, 330 territory-years)

- High Risk (n=46 territories, 394 territory-years)

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## Hazard Assessment - Results

**Matrix*********	****Low****	****Mod****	****High****	****Xhigh****	****Reference**
**Fish********	0-0.1	0.1-0.2	0.2-0.4	>0.4	Barr 1986, This Study
**Eggs**	0-0.5	0.5-1.3	1.3-2.0	>2.0	Evers et al. 2003
**Blood-J**	0-0.1	0.1-0.3	0.3-0.4	>0.4	Meyer et al. 1998***
**Blood-A**0-1.0	1.0-3.0	3.0-4.0	>4.0	This Study, Nocera 1999
**Feather**	0-9	9-20	20-30	>30	Thompson 1998
- *  Total Hg levels in ug/g, blood and eggs are ww and feathers are fw
- ** Represents 10-15 cm Yellow Perch, ww, whole body analysis
- ***Applies to 3-5 week old chicks only

- LOAEL

- NOAEL

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## New England risk characterization Opportunistic and Random Sampling Design

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## Common Loon Population Model

- Under construction
- Demographic parameters mostly known
- Needs to be spatially explicit
- Will provide a test dose for Hg that is based on:
- Wild populations
- Population level
- Results to date
- Lamda = 0.48 fledged
- 	 young/territorial pair
- Validated through NH
- 	and VT long-term
- 	datasets

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## Uncertainty Factors

- Interspecies Uncertainty
- Measurements of various species in same areas (comparative exposure profile)
- Develop hazard assessments
- LOAEL to NOAEL Uncertainty
- Use dose-response curve
- Conservative because impacts in the moderate category not used
- Subchronic to Chronic Uncertainty
- Uncertainty factor is minimal if using sublethal

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## Bioaccumulation Factor

- Total Hg in unfiltered water related to yellow perch Hg (whole body, ww)
- BAF for Trophic Level 3 fish (5-15 cm) = 86,250
- BAF for Trophic Level 4 fish (15-25 cm) = 156,330
- Total Hg in unfiltered water related to perch or perch equivalents
- Best relationship with 5-10 cm size class (explains 55% of variation)
- Species-to-species conversion is 1.15 for centrarchids, golden shiner, trout
- Water-fish MeHg relationship is being investigated in New York

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## Cumulative perch Hg levels compared to adult loon blood Hg levels

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## Additional parameters required in WCV (Loon)

**Body Weight  (WT****A****) g**
- Sexual dimorphism is 21%
- Mean female weight of 4,714 +/- 302g (n=157, range=4,000 to 4,800)
- Mean male weight of 5,953 +/-412g (n=153, range=4,600 to 7,550)
**Ingestion Rate (FA) g/day**
- 20% of weight (Barr 1996)
- 1,190 +/- 82 g for males
- 943 +/- 60 g for females
**Percent of diet at each trophic level**
- Trophic Level 3 and 4....Male = 73% and 27%
- Trophic Level 3 and 4....Female = 83% and 17%
**Test Dose:**
- Based on weight of evidence impacts of a chronic MeHg dose of ~0.20 ug/g
- Male = 179 ug Hg/kg bw/day
- Female = 142 ug Hg/kg bw/day
**Reference Dose:**
- Test Dose/Uncertainty Factors

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## Test Dose

- Based on  multiple lines of evidence
- Dietary uptake of 0.20 ug/g of MeHg is equivalent to approximately
- 3.0 ug/g in blood,
- 1.3 ug/g in eggs,
- 9% annual increase in feathers
- Smaller eggs, weight loss
- Significantly less time on nest and foraging
- 40% fewer fledged young

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## WCV for Hg based on population levels of the Common Loon

- WCV Male Loon =                     0.179 mg/kg/d x [1/3 x 1 x 2)]) x 5.95 kg
- 		             0.012 L/d + [(0.73) (1.19 kg/d x 72,000) + (0.27) (1.19 kg/d x 142,000)
**WCV ****Male Loon**** = 1.65 ng/L**
- WCV Female Loon =                     0.142 mg/kg/d x [1/3 x 1 x 2)]) x 4.71 kg
- 		           0.012 L/d + [(0.83) (0.943 kg/d x 72,000) + (0.17) (0.943 kg/d x 142,000)
**WCV ****Female Loon ****= 1.41 ng/L**** **

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## WCV for Hg for mink and river otter

- WCV Mink =                     0.055 mg/kg/d x [1/1 x 1 x 3)]) x 0.8 kg
- 		                                          0.012 L/d + [(0.73) (1.78 kg/d x 72,000)
**WCV ****Mink**** = 1.14 ng/L**
- WCV River Otter =                     0.055 mg/kg/d x [1/1 x 1 x 3)]) x 7.40 kg
- 		                0.012 L/d + [(0.80) (1.22 kg/d x 72,000) + (0.20) (1.22 kg/d x 142,000)
**WCV**** ****River Otter ****= 1.29 ng/L**** **

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## Comparison of WCVs (ng/L)

- Species		GLWQI	EPA		MDEP
- Belted Kingfisher	1.04		0.60		NA
- Bald Eagle		1.92		1.82		NA
- Mink			2.88		1.04		1.14
- River Otter		1.93		0.76		1.29
- Loon – female	NA		0.82		1.41
- Loon – male		NA		NA		1.65

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## Next steps

- Test WCV methods in another geographic area.
- A 3-year randomized study in New York is nearly final.
- Reduce uncertainty factors including species-to-species.
- Include gamefish species at trophic 4 level
- Finalize spatially explicit population model and water-fish-loon relationships.
- Collaboration on a modeling effort “MERGANSER” by USEPA AND USGS will provide a standard loon unit
- Publications are in preparation.

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## CollaboratorsSpearheaded by the Maine Dept. of Environmental Protection	

**FEDERAL GOVERNMENT**
- U.S. Fish and Wildlife Service – New England Field Office and Office of Migratory Bird Mgmt.
- U.S. EPA – ORD Narragansett Office – Atlantic Ecological Div. & the New England Field Office
- U.S.D.A. – Northeastern Ecosystem Research Cooperative
- Canadian Wildlife Service
**STATE GOVERNMENT**
- Maine Dept. of Environ. Protection & Inland Fish and Wildlife
- Mass. Metropolitan Dist. Comm.
- NH Dept. of Environ. Service
- NY State Dept. of Environ. Cons.
- Vermont Dept. of Environ. Cons.

**NON-PROFIT ORGANIZATIONS**
- Loon Preservation Committee
- Maine Audubon Society
- Vermont Inst. Of Natural Science
- Adirondack Coop. Loon Program
- New England Forestry Foundation
- Wildlife Conservation Society
- University of Pennsylvania
- Texas A&M Trace Element Res. Lab
- Tufts University
- Univ. of Southern Maine
**INDUSTRY**
- FPL Energy Maine Hydro
- New York State Energy Research and Development Authority

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