1. Slide 1
Scientific Studies Reveal Causes of Biological Mercury Hotspots January 9, Findings from two new papers in the journal BioScience A project of the Hubbard Brook Research Foundation Science Links program
Papers available here with complete list of authors
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If you are joining by phone please note that we will be referring to specific slides and the power point presentation can be found at:

2. 11 Authors Slide 2 Charles T. Driscoll, PhD – Syracuse University
David Evers, PhD - BioDiversity Research Institute
Thomas Butler, PhD – Cornell University
Celia Y. Chen, PhD – Dartmouth College
Thomas A. Clair, PhD – Environment Canada
M. Wing Goodale – BioDiversity Research Institute
Young-Ji Han, PhD – HBRF
Thomas M. Holsen, PhD – Clarkson University
Neil C. Kamman – Vermont DEC
Kathy Lambert – Hubbard Brook Research Foundation
Ron Munson, PhD – Tetra Tech
Present today for comment – Gerald Keeler, PhD – University of Michigan

3. New BioScience Studies
Slide 3
New BioScience Studies
Mercury Contamination in Forest and Freshwater Ecosystems in the Northeastern United States: Sources, Transformations, and Management Options
Biological Mercury Hotspots in the Northeastern U.S. and Southeastern Canada
Mercury Matters: Linking Mercury Science with Public Policy in the Northeastern United States

4. Outline of Today’s Presentation
Slide 4
Outline of Today’s Presentation
1. Background – Kathy Fallon Lambert
2. What are Biological Mercury Hotspots? – David Evers
3. What are the Causes? – Charles Driscoll
4. How Significant are U.S. Coal-fired Power Plants? – Thomas Holsen
5. Conclusions – Charles Driscoll
We will each present 5 slides then open it up for questions…

5. Key Findings Slide 5 1. Biological mercury hotspots do exist.
2. Specific hotspots linked to causes for the first time.
3. Airborne mercury emissions are the dominant source.
4. They produce a double-whammy in watersheds hit by decades of acid rain.
5. And cause ripple effects in reservoirs that are manipulated for power production.
6. New Hampshire case study demonstrates we’ve reached tipping point: coal-fired power plants have significant local impacts that are under-estimated by EPA.
7. Good news – document for first time in the Northeast that rapid recovery in fish and loons can occur if local emissions reduced.
8. Findings validate state concerns about mercury trading and need for new draft Federal legislation.

6. What is Mercury and Why is it a Problem?
Slide 6
What is Mercury and Why is it a Problem?
Advisories are useful, but they are somewhat blunt and don’t identify areas particularly high in mercury
44 states have one or more fish advisories

7. Where Does Mercury in Fish and Wildlife Come From?
Slide 7
Where Does Mercury in Fish and Wildlife Come From?
Dominant source of mercury to most watersheds is atmospheric emissions and deposition.
Mercury deposited is either near or far from source depending on its form
Then converted to methyl mercury in the watershed - more readily absorbed by people and animals
Methyl mercury strongly bioaccumulates in food chain, increasing in concentration up to 10 million times from water to loons
Exposure through the aquatic food web is largely from fish consumption

8. Where Does Mercury Pollution Come From?
Slide 8
Where Does Mercury Pollution Come From?
Globally, Asia is the largest source.
Leads some to believe that US sources are not as important to US deposition
Total: 2076 short tons
Total: 2496 short tons

9. Northeast Sediment Trends Reflect US Emissions Pattern
Slide 9
Northeast Sediment Trends Reflect US Emissions Pattern
Location of emission sources matter – not all mercury transported globally
Seepage Pond – reflects direct atmospheric inputs
Recent declines are consistent with declines in US emisions whereas global emissions have remained the same or gone up slightly
Decrease in recent years
These patterns have been observed widely across eastern North America
Pirrone et al , Lorey and Driscoll 1999.

10. What is the Current Mercury Policy Context?
Slide 10
What is the Current Mercury Policy Context?
US EPA Clean Air Mercury Rule
Two-phase program for coal-fired power plants
20% reduction by 2010
70% reduction by 2025
Cap-and-trade approach
State Implementation Plans
Approx. 24 of 30 states filed more stringent plans
21 = deeper cuts
18 = faster cuts
17 = no trading
Viability cap and trade program if many states opt out

11. What Are Biological Mercury Hotspots and Where Do They Occur?
Slide 11
What Are Biological Mercury Hotspots and Where Do They Occur?
David C. Evers, PhD
BioDiversity Research Institute

12. Biological Mercury Hotspot Definition
Slide 12
Biological Mercury Hotspot Definition
“A location on the landscape that, compared to the surrounding landscape, is characterized by elevated concentrations of mercury in fish and wildlife that exceed established human or wildlife health criteria as determined by a statistically adequate sample size.”
1. Analyzing data for hotspots allows us to locate areas that stand out from general fish consumption advisories
2. Includes fish and wildlife
Evers et al

13. Biological Mercury Hotspots
Slide 13
Biological Mercury Hotspots
Upper Ken. and Andro. Rivers
Nova Scotia
Upper Connecticut River
Lower Merrimack watershed
5 confirmed
9 suspected
Five confirmed, nine suspected from Nova Scotia to NY
2. Highest mercury levels in yellow perch = Merrimack River where average is 0.78 and maximum values are more than 10 times higher than EPA human health criterion.
3. Highest levels in common loon blood – Keji, NS. Average = 5.5 ppm, 93% exceed 3.0 ppm
4. Primary mechanisms – atmospheric deposition amplified by water sensitivity, reservoir fluctuation, and large local sources
5. The important role of atmospheric emissions and deposition has implications for policy and the advisability of mercury trading
6. Point sources from contaminated sites do occur and may be responsible for some of the suspected hotspots = former Holterchem site
Adirondacks
Evers et al

14. Methods 1. Based on 7,311 observations 2. Human health analysis
Slide 14
Methods
1. Based on 7,311 observations
2. Human health analysis
- Indicator = yellow perch
- Threshold = 0.3 ppm (EPA criterion)
3. Ecological health analysis
- Indicator = Common loon blood
- Threshold = 3.0 ppm

15. How Does Our Approach Differ From EPA’s?
Slide 15
How Does Our Approach Differ From EPA’s?
1. We used a more inclusive definition of hotspot.
- Not limited to “consumable fish” with methyl mercury concentrations “attributable solely to utilities” above EPA criterion of 0.3 ppm
2. By focusing regionally and on more species, we used a larger biological database.
- Not limited to select sites and species from the National Fish Tissue Survey and Advisory Listing.

16. What are the Causes of Biological Mercury Hotspots?
Slide 16
What are the Causes of Biological Mercury Hotspots?
Charles T. Driscoll, PhD
Syracuse University

17. New Results: Causes of Biological Mercury Hotspots
Slide 17
New Results: Causes of Biological Mercury Hotspots
Global and Regional Atmospheric Emissions and Deposition
Reservoir Fluctuations
Local Emissions
Landscape Sensitivity
Evers et al

18. Sensitive Watersheds: Abundant forest cover and wetlands
Slide 18
We Found that Some Biological Hotspots Are Caused by Moderate Mercury Deposition to Sensitive Watersheds
Sensitive Watersheds:
Abundant forest cover and wetlands
Impacted by acid rain
Shallow groundwater flow paths
For example, the Adirondacks have been hit by acid rain and are now more sensitive to mercury pollution.
Areas like the Adirondacks receive double-whammy of acid rain and mercury.
Driscoll et al

19. Slide 19
New Finding: Biological Hotspots Detected in Reservoirs Manipulated for Power Production
Evers et al

20. Mercury Levels Higher in Reservoirs With Large Fluctuations
Slide 20
Mercury Levels Higher in Reservoirs With Large Fluctuations

21. Slide 21
New Model Results: Major Biological Hotspot Caused by High Mercury Deposition from Local Sources
If sources are not controlled, could perpetuate the existence of these hotspots
Maximum deposition = 76 µg/m2-yr
Evers et al

22. Tom Holsen, PhD Clarkson University
Slide 22
How Significant are Local Emission Sources and What Role Do Coal-fired Power Plants Play?
Tom Holsen, PhD
Clarkson University

23. U.S. Total Mercury Emissions
Slide 23
U.S. Total Mercury Emissions
1. As you’ve heard from previous speakers, local and regional emission sources in the US are important to deposition in the US.
2. The largest emission source in the US is coal-fired power plants.
3. Some sources such as incinerators have made dramatic reductions in emissions, but coal-fired power plants have not changed substantially.
After EPA National Trends Inventory, 2006.

24. New Results Differ From EPA’s
Slide 24
New Results Differ From EPA’s
We used a case study approach to determine mercury deposition near a biological hotspot in southern NH and northeastern MA and estimate the contribution of coal-fired power plants to emissions in near that hotspot.
2. Maps show results from two different studies that have different objectives – national approach versus local scale
3. Map on left shows that mercury deposition in NH tends to be moderate or low (6-10 µg/m2-yr), but there is an area of particularly high deposition near several large emission sources in the southern part of the study region (76 µg/m2-yr)
4. Different approach gives different results – national approach estimates deposition in same area as µg/m2-yr
5,. Should point out that even though are numbers are higher, we do not account for deposition from sources beyond ^ km whereas EPA model does.

25. How & Why Do These Results Differ?
Slide 25
How & Why Do These Results Differ?
Deposition
Our estimate = µg/m2-yr (local and regional)
4-5 times higher than EPA estimates (all sources)
Why?
We used a local scale plume model and detailed Northeast emissions inventory.
EPA used a larger scale grid model and coarse national emissions inventory.
Implications
Suggests finer resolution modeling is needed to characterize deposition patterns near large sources – even outside heavily industrialized regions.

26. Slide 26
New Model Results Highlight the Role of Coal-fired Power Plants in Hotspots
Evers et al
Scenario:
90% emissions reductions from 4 coal-fired power plants
EPA estimates the utilities contribute 5 to 10 percent of total mercury deposition in southern NH
Deposition
After Evers et al

27. Results Supported by Other Studies J. Keeler and Colleagues
Slide 27
Results Supported by Other Studies J. Keeler and Colleagues
1. Results in MI, OH, and VT show that EPA estimates of wet mercury deposition are 34-56% lower than measured values.
2. Steubenville, Ohio Study (Keeler et al. 2006)
~ 80% of wet mercury deposition is attributable to local/regional anthropogenic sources.
~ 70% is attributable to coal combustion.

28. Adverse effect threshold
Slide 28
Good News: Fish and Wildlife Can Respond Rapidly to Emissions Reductions
Mercury air emissions from local upwind sources declined 45% from 1997 – 2002.
64% decline
Adverse effect threshold
Findings further corroborate connection between local emissions and biological mercury hotspots.
Substantial local contribution corroborated by biological data
The loon data are consistent with fish (largemouth bass and yellow) and zooplankton trends
After Evers et al

29. Key Findings Slide 29 1. Biological mercury hotspots do exist.
2. Specific hotspots linked to causes for the first time.
3. Airborne mercury emissions are the dominant source.
4. They produce a double-whammy in watersheds hit by decades of acid rain.
5. And cause ripple effects in reservoirs that are manipulated for power production.
6. New Hampshire case study demonstrates we’ve reached tipping point: coal-fired power plants have significant local impacts that are under-estimated by EPA.
7. Good news – document for first time in the Northeast that rapid recovery in fish and loons can occur if local emissions reduced.
8. Findings validate state concerns about mercury trading and need for new draft Federal legislation.