Atm ospheric Deposition, Atm ospheric Deposition, Transport, Transform ations , Transport, Transform ations , Fate and Bioavailability of Fate and Bioavailability of Mercury in Forested Mercury in Forested W atersheds of the W atersheds of the Northeastern U.S. Northeastern U.S.
Outline Outline � Upland transformations Upland transformations � � Wetland Wetland- - surface water dynamics surface water dynamics � � Patterns in aquatic biota Patterns in aquatic biota � � MCM MCM- - HD HD – – Model calculations Model calculations �
Collaborators Collaborators � Ron Munson Ron Munson - - Tetra Tech Tetra Tech � � Jason Demers Jason Demers - - Cornell Cornell � � Neil Neil Kamman Kamman - - VT DEC VT DEC � � David Evers David Evers - - Biodiversity Research Institute Biodiversity Research Institute � � Tom Tom Holsen Holsen, Hyun , Hyun- - Deok Deok Choi Choi – – Clarkson Clarkson � � Eric Miller Eric Miller – – Ecosystem Research Group Ecosystem Research Group � � Brian Brian Branfireum Branfireum - - Toronto Toronto �
Site Description Site Description Adirondack Park Sunday Lake Watershed Arbutus Lake Watershed
Study Region and Mercury Datasets Evers 2005. Mercury Connections.
Leaf tissue Leaf tissue Litterfall Canopy air Canopy air Deposition Throughfall Evasion Root tissue Root tissue Soil Water Soil Water Soil Soil Soil
10 Wet Hg Deposition - 6.9 ug/m2-yr Huntington Forest Biscuit Brook 8 Total Hg (ng/L) 6 4 2 0 1999 2000 2001 2002 2003 2004 2005 Year
Forest Ecosystem Hg Mass Balance Forest Ecosystem Hg Mass Balance
Forest Ecosystem Hg Mass Balance Forest Ecosystem Hg Mass Balance 24.3
Mercury Flux from Soil Surface Mercury Flux from Soil Surface THg Flux [ng m -2 hr -1 ] 10 15 20 25 0 5 13:00: 17:00: Temperature [ o C] RH [%] Hg Flux 21:00: 01:00: 05:00: 09:00: Time of Day 13:00: 17:00: 21:00: 01:00: 05:00: 09:00: 13:00: 40 50 60 70 80 90 100 Relative Humidity [%] 16 18 20 22 24 26 28 Temperature [ o C]
From Miller et al. 2 0 0 5 .
Mercury in Fish by Species Mercury in Fish by Species
Lake-w atersheds vary in their sensitivity to m ercury inputs based on: 1 . Land Cover ( e.g., forest, w etlands) 2 . Hydrologic flow paths 3 . Aquatic productivity
Mercury Cycling Model for Headw ater Mercury Cycling Model for Headw ater Drainage Lakes ( MCM - - HD) HD) Drainage Lakes ( MCM ATMOSPHERIC CANOPY INTERACTIONS WETLAND Hg PROCESSES DEPOSITION Volat ilizat ion D Precipit at ion n e m o e i t t h c u y d l a Hg (O) e t R i o Part icle n Capt ure Hg (II) CH3 -Hg Throughfall M e n t h i o y l a t SOIL HYDROLOGIC WETLAND WATER SOIL CHEMICAL PROCESSES PROCESSES QUALITY/HYDROLOGY Rain R-SH Hg R-SH Hg … ET Organic Complexat ion … Hg Hg Clay Sorpt ion
Sunday Lake I nlet Calibration: Sunday Lake I nlet Calibration: Total Hg Total Hg 10 Simulated 8 Observed Total Hg (ng/l) 6 4 2 0 Aug/31/00 Aug/31/01 Sep/1/99 Sep/1/02 Date
Sunday Lake I nlet Calibration: Sunday Lake I nlet Calibration: Methyl Hg Methyl Hg 3 Simulated Observed Methyl Hg (ng/l) 2 1 0 Aug/31/01 Aug/31/00 Sep/1/99 Sep/1/02 Date
Sunday Lake: Sim ulated Response of Fish Sunday Lake: Sim ulated Response of Fish Hg to 1 5 % and 5 0 % Decreases in Hg to 1 5 % and 5 0 % Decreases in Atm ospheric Hg Deposition Atm ospheric Hg Deposition 1.2 1 Yellow Perch Hg (ug/g) 0.8 0.6 Mercury Deposition at Current Level 0.4 Mercury Deposition Reduced 50% 0.2 Mercury Deposition Reduced 15% 0 0 100 200 300 400 500 Simulation Year
Conclusions Conclusions � The forest canopy enhances Hg deposition The forest canopy enhances Hg deposition � � Hg inputs are retained in soil, re Hg inputs are retained in soil, re- - emitted emitted � to the atmosphere or lost with drainage to the atmosphere or lost with drainage � Wetlands enhance the supply and Wetlands enhance the supply and � transport of MeHg MeHg transport of � Marked bioaccumulation of Marked bioaccumulation of MeHg MeHg occurs in occurs in � the aquatic food chain the aquatic food chain � The western Adirondacks is a Hg “hotspot” The western Adirondacks is a Hg “hotspot” �
Research Needs Research Needs � Dry deposition (total deposition) Dry deposition (total deposition) � � Fate of soil Hg Fate of soil Hg � � Soil re Soil re- - emissions emissions � � Response of fish Hg to changes in Hg Response of fish Hg to changes in Hg � inputs and acid rain inputs and acid rain
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