moderators summary 2004 mercury workshop 2004 mercury workshop

Moderators SummaryModerators Summary

2004 Mercury Workshop2004 Mercury Workshop

http://www.usgs.gov/

http://westnilemaps.usgs.gov/mercuryworkshop/

Overview of Mercury Research and Overview of Mercury Research and Relations to DOI Resource Relations to DOI Resource

ManagementManagement• Mercury is a problem at a global and a local scale.Mercury is a problem at a global and a local scale.• Atmospheric deposition is a major pathway and Atmospheric deposition is a major pathway and

man’s sources of emissions continue to make a man’s sources of emissions continue to make a major global and local contribution.major global and local contribution.

• ““Where” mercury is deposited also plays a critical Where” mercury is deposited also plays a critical role – some major drivers on the landscape are role – some major drivers on the landscape are pH, wetlands, wetting/drying cycles, sulfur, pH, wetlands, wetting/drying cycles, sulfur, carbon.carbon.

• ““New” loading of mercury matters – New” loading of mercury matters – bioavailability.bioavailability.

• Disturbances (fire, dredging, global warming) and Disturbances (fire, dredging, global warming) and land management (wetland restoration & land management (wetland restoration & construction, reservoir construction, erosion, construction, reservoir construction, erosion, mining, mine restoration, fire, land-use changes) mining, mine restoration, fire, land-use changes) profoundly influence the mercury problem.profoundly influence the mercury problem.


ManagementManagement• Power utilities, municipal, and medical waste Power utilities, municipal, and medical waste

incinerators are major sources of emissions.incinerators are major sources of emissions.• Two important regulatory measures are: MACT Two important regulatory measures are: MACT

Standards and Clean Air Interstate Rule (CAIR )Standards and Clean Air Interstate Rule (CAIR )• USEPA estimates the costs of controls in the USEPA estimates the costs of controls in the

billions $ and the benefits in the tens of billions $.billions $ and the benefits in the tens of billions $.• DOI agencies and Native Americans have lands DOI agencies and Native Americans have lands

that are both vast in size (land and sea) and that are both vast in size (land and sea) and highly decentralized.highly decentralized.

• Agencies need to better understand sources, Agencies need to better understand sources, transport, and fate of mercury.transport, and fate of mercury.

• Effects on individual biological species and Effects on individual biological species and ecosystemsecosystems


ManagementManagement• DOI agencies need research on the specific DOI agencies need research on the specific

ecosystem characteristics and processes that ecosystem characteristics and processes that influence the rate at which Hg methylates and influence the rate at which Hg methylates and demethylates.demethylates.

• DOI agencies need research on the specific physical, DOI agencies need research on the specific physical, chemical, and biological factors that influence the chemical, and biological factors that influence the rate at which Hg methylates and demethylates.rate at which Hg methylates and demethylates.

• DOI agencies need research on management DOI agencies need research on management techniques for lessening methylation rates.techniques for lessening methylation rates.

• We need to emphasize the role of long-term We need to emphasize the role of long-term monitoring and trend analysis in all media.monitoring and trend analysis in all media.

• DOI agencies need a variety of decision support DOI agencies need a variety of decision support tools – maps, models, databases.tools – maps, models, databases.

• We need to consider the role of DOI lands as We need to consider the role of DOI lands as locations for monitoring and research.locations for monitoring and research.


ManagementManagement• We need to understand the connection between We need to understand the connection between

the marine and the terrestrial environment.the marine and the terrestrial environment.• We need to increase the level and clarity of the We need to increase the level and clarity of the

information that we provide.information that we provide.• People who do subsistence fishing have a much People who do subsistence fishing have a much

greater exposure to mercury through their greater exposure to mercury through their consumption, 180 lb/year.consumption, 180 lb/year.

• We need to understand the movement of mercury We need to understand the movement of mercury through the food chain.through the food chain.

• We need to understand reproductive and We need to understand reproductive and developmental impacts to biota.developmental impacts to biota.

• Need to look at synergistic effects w/ other Need to look at synergistic effects w/ other constituentsconstituents

Case Studies on DOI Lands and Effects Case Studies on DOI Lands and Effects of Land Management on Mercuryof Land Management on Mercury

• Understanding environmental influences on Understanding environmental influences on methylmercury levels in aquatic systemsmethylmercury levels in aquatic systems– looking across gradients in environmental factorslooking across gradients in environmental factors

• Common correlations with [MeHg] across case Common correlations with [MeHg] across case studies:studies:– sulphate, DOC, pH, (different ranges?), wet/dry cyclessulphate, DOC, pH, (different ranges?), wet/dry cycles– sometimes linear relationships (pH), some not (sulphate)sometimes linear relationships (pH), some not (sulphate)

• Other factors were more case-specific:Other factors were more case-specific:– local land-use issueslocal land-use issues– importance of local emission sources importance of local emission sources – lakes vs. wetlandslakes vs. wetlands


• Value of integrated studiesValue of integrated studies– need to consider deposition/inputs, methylation and food need to consider deposition/inputs, methylation and food

webswebs

• Value of long-term studiesValue of long-term studies– associating reductions in abiotic and biotic [MeHg] in associating reductions in abiotic and biotic [MeHg] in

Everglades with local emission reductionsEverglades with local emission reductions

• Value of combining field and experimental studiesValue of combining field and experimental studies– cause-effect linkages confirmed by lab/mesocosm/whole cause-effect linkages confirmed by lab/mesocosm/whole

ecosystem experimentsecosystem experiments


ChallengesChallenges

• How can we integrate findings from many case studies How can we integrate findings from many case studies to provide better understanding?to provide better understanding?

• To what extent can new insights from one area be To what extent can new insights from one area be reliably applied to others? (eg. inputs of “new” vs. reliably applied to others? (eg. inputs of “new” vs. “old” mercury, etc.)“old” mercury, etc.)

• How can we better use the findings from case studies How can we better use the findings from case studies to help land/resource managers, pollution regulators, to help land/resource managers, pollution regulators, industry, etc. make better decisions? industry, etc. make better decisions?

• How are mercury issues affected by other How are mercury issues affected by other management concerns? (eg. acidic deposition, climate management concerns? (eg. acidic deposition, climate change, etc.)change, etc.)

Biological effectsBiological effects

• For birds, embryonic stage most sensitive to Hg.For birds, embryonic stage most sensitive to Hg.

• Mallards in the lab: embryotoxic threshold = 0.8-Mallards in the lab: embryotoxic threshold = 0.8-1.0 ppm in egg.1.0 ppm in egg.

• Egg injection studies to simulate field exposure of Egg injection studies to simulate field exposure of Hg.Hg.

• Piscivorous species are more sensitive to Hg.Piscivorous species are more sensitive to Hg.

• To produce 0.8-1.0 ppm in egg, food = ~0.1 ppm.To produce 0.8-1.0 ppm in egg, food = ~0.1 ppm.

• If Hg criterion (0.1 ppm) is protective for wildlife, If Hg criterion (0.1 ppm) is protective for wildlife, should be protective for humans.should be protective for humans.


• For humans, mercury in blood is methylmercury For humans, mercury in blood is methylmercury and primary source is fish.and primary source is fish.

• Toxicity depends on dose and developmental Toxicity depends on dose and developmental period.period.

• Fetal neurotoxicity: 1/5 – 1/10 exposure that Fetal neurotoxicity: 1/5 – 1/10 exposure that adversely affects adultsadversely affects adults

• Reference Hg dose, 35 ug/L; about 600,000 Reference Hg dose, 35 ug/L; about 600,000 newborns above this dose.newborns above this dose.

• Other possible mercury risks:Other possible mercury risks:– CardiovascularCardiovascular– Reproductive and endocrineReproductive and endocrine– Persistent and delayed neurotoxicityPersistent and delayed neurotoxicity


• In the lab, fathead minnows fed methylmercury In the lab, fathead minnows fed methylmercury had reduced reproductive success and altered had reduced reproductive success and altered reproductive behavior and hormone levels.reproductive behavior and hormone levels.

• Northern pike from the field from VNP analyzed Northern pike from the field from VNP analyzed for Hg and hormonesfor Hg and hormones– Testosterone suppressed by melthylmercuryTestosterone suppressed by melthylmercury– Unknown population effectsUnknown population effects

Biological effectsBiological effects• Proposed avian indicator species for mercury Proposed avian indicator species for mercury

contaminationcontamination• High correlation between fish prey Hg & loon High correlation between fish prey Hg & loon

blood.blood.• High correlation between Hg in loon blood & eggs.High correlation between Hg in loon blood & eggs.• Increase in Hg in bird blood from marine to Increase in Hg in bird blood from marine to

estuarine to river to lake.estuarine to river to lake.• Trend to higher Hg in adult than in young birdsTrend to higher Hg in adult than in young birds• Trend to higher Hg in the larger sex of each Trend to higher Hg in the larger sex of each

speciesspecies• Common loon proposed for national indicator Common loon proposed for national indicator

programprogram• There is an ecological impact to individual loons There is an ecological impact to individual loons

and likely population effects from Hgand likely population effects from Hg

Tools for Accessing Data, Models, and Tools for Accessing Data, Models, and Ancillary InformationAncillary Information

• A huge volume of data on Hg in fish and other A huge volume of data on Hg in fish and other biota have been collected over time.biota have been collected over time.

• These data are beginning to become available to These data are beginning to become available to other investigators through development of large other investigators through development of large databases that collect data for numerous projects.databases that collect data for numerous projects.

• Making these data available and modeling the Making these data available and modeling the data can serve users by reducing the costs of data can serve users by reducing the costs of projects by reducing the need to collect new data.projects by reducing the need to collect new data.


• One problem to further collecting/aggregating One problem to further collecting/aggregating data is incompatibility in data formats and/or mis-data is incompatibility in data formats and/or mis-entered or missing meta data.entered or missing meta data.

• Fish tissue; the “Wente” National dataset. Fish tissue; the “Wente” National dataset. Contains 45K records of fish tissue, with potential Contains 45K records of fish tissue, with potential for up to 100K records. for up to 100K records.

• EMMMA@usgs,govEMMMA@usgs,gov


• NADP –MDN data – Weekly monitoring of wet Hg NADP –MDN data – Weekly monitoring of wet Hg (plus occasionally dry). There is the need to (plus occasionally dry). There is the need to expand MDN coverage. Nonetheless, these MDN expand MDN coverage. Nonetheless, these MDN measurements are collectively indicating a general measurements are collectively indicating a general decrease in wet Hg deposition. This monitoring decrease in wet Hg deposition. This monitoring needs to continue.needs to continue.

GOOGLE: Mercury Deposition NetworkGOOGLE: Mercury Deposition Network

• 17K record dataset (3.2 Hg records) for 17K record dataset (3.2 Hg records) for contaminants in wildlife. contaminants in wildlife. WWW.PWRC.USGS.gov/contaminants-onlineWWW.PWRC.USGS.gov/contaminants-online


• Other datasets are available to compliment these Other datasets are available to compliment these data collections. A strong recommendation data collections. A strong recommendation would be to allocate $ to make these large would be to allocate $ to make these large datasets more complete.datasets more complete.

• New data should be collected in such a way as to New data should be collected in such a way as to promote data consistency at Regional/National promote data consistency at Regional/National scales.scales.

Mercury Sources: SummaryMercury Sources: Summary• Local sources MATTERLocal sources MATTER– Weight of evidence so far suggests Weight of evidence so far suggests

that local and continental that local and continental atmospheric sources DRIVE supply atmospheric sources DRIVE supply of reactive Hg (RM) of reactive Hg (RM)

– CaveatsCaveats• Global atmospheric sources are Global atmospheric sources are

becoming more importantbecoming more important

• Hgº half life is key modeling factor, Hgº half life is key modeling factor, but measurements to date support a but measurements to date support a longer Dep at pristine sites are likely longer Dep at pristine sites are likely half global; half N. Americanhalf global; half N. American

• New Hg 8x more “available than oldNew Hg 8x more “available than old

• MANY PATHWAYSMANY PATHWAYS– Wet DepWet Dep– Dry DepDry Dep– GeologicalGeological

• MiningMining

• Weathering/naturalWeathering/natural

• GeothermalGeothermal

Hg0

(Wet + Dry)

So42-

AXIS OF Methylation

Doc

RGM PgM Geo_M

RM

1)1)Relative importance of a given Relative importance of a given pathway depends on LOCATION (That pathway depends on LOCATION (That means MAPS)means MAPS)

2)2)Relative Importance of Hg sources to Relative Importance of Hg sources to methylation depends other factors on methylation depends other factors on the ground (That means more MAPS)the ground (That means more MAPS)

Mercury Sources: a management Mercury Sources: a management perspectiveperspective

• Think like a manager:Think like a manager:– $20-50k (if you are lucky!)$20-50k (if you are lucky!)

• Need to focus money on most important, or the best guess as to what’s Need to focus money on most important, or the best guess as to what’s most importantmost important

– Long-term sensitive indicator (often, no “s” at park funding levels) of Long-term sensitive indicator (often, no “s” at park funding levels) of Hg risk Hg risk

– Get to know your NPS region’s Inventory & Monitoring coordinators!Get to know your NPS region’s Inventory & Monitoring coordinators!

• Approaches: What to measure/monitor?Approaches: What to measure/monitor?– Birds, Fishes (i.e., Hearn descriptive maps)?Birds, Fishes (i.e., Hearn descriptive maps)?– Axis of “Methylation” (i.e., process-based)Axis of “Methylation” (i.e., process-based)

• SOSO442-2-, DOC, etc are the other factors besides Hg availability that contribute , DOC, etc are the other factors besides Hg availability that contribute

to MeHgto MeHg

– Both have been applied in GIS/Map-based frameworksBoth have been applied in GIS/Map-based frameworks• Hearn and Wente--maps descriptive/empirical Hearn and Wente--maps descriptive/empirical

• Booth et al--processes/axis of Meth.. (see poster)Booth et al--processes/axis of Meth.. (see poster)

• DATA QUALITY ACTDATA QUALITY ACT– Uncertainty has to be quantified and identifiedUncertainty has to be quantified and identified

• LOCATION, LOCATION, LOCATION--MAPSLOCATION, LOCATION, LOCATION--MAPS

Mercury Sources: Which is important Mercury Sources: Which is important where?where?

Mercury Sources: How to communicate Mercury Sources: How to communicate with Managerswith Managers

Seigneur, C., K. Vijayaraghavan, K. Lohman, P. Karamchandani and C. Scott, 2004. Global source attribution for mercury deposition in the United States. Environmental Science & Technology 38(2), 555-569.

(Maps and map tools are better (Maps and map tools are better than just papers for busy than just papers for busy managers-synthesis)managers-synthesis)

Influence of Ecosystem Setting on Influence of Ecosystem Setting on Mercury and Mercury ManagementMercury and Mercury Management

• DOC/S/Hg TriadDOC/S/Hg Triad- Controls Hg dynamics mainly by influencing- Controls Hg dynamics mainly by influencing

microbial community structuremicrobial community structure

• Many ecosystem factors control the DOC/S/Hg TriadMany ecosystem factors control the DOC/S/Hg Triad- landscape dynamics - landscape dynamics

(pH, eutrophication, water level,fire)(pH, eutrophication, water level,fire)- ecosystem type (e.g. SW marsh vs. FW marsh)- ecosystem type (e.g. SW marsh vs. FW marsh)- food-web dynamics- food-web dynamics- elevation- elevation

Influence of Ecosystem Setting on Influence of Ecosystem Setting on Mercury and Mercury ManagementMercury and Mercury Management

• Coordination of existing programs may be Coordination of existing programs may be sufficient to help us assess ecosystem response sufficient to help us assess ecosystem response to emission reductions (instead of a large to emission reductions (instead of a large federally funded program)federally funded program)

• Ecosystems are complex, no one factor drives Hg Ecosystems are complex, no one factor drives Hg bioavailabilitybioavailability

• What information is most useful to ecosystem What information is most useful to ecosystem managers?managers?

moderators summary 2004 mercury workshop 2004 mercury workshop

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