Spatiotemporal patterns of mercury accumulation in lake sediments of western North America.
For the Western North America Mercury Synthesis, we compiled mercury records from 165 dated sediment cores from 138 natural lakes across western North America. Lake sediments are accepted as faithful recorders of historical mercury accumulation rates, and regional and sub-regional temporal and spatial trends were analyzed with descriptive and inferential statistics. Mercury accumulation rates in sediments have increased, on average, four times (4×) from 1850 to 2000 and continue to increase by approximately 0.2μg/m(2) per year. Lakes with the greatest increases were influenced by the Flin Flon smelter, followed by lakes directly affected by mining and wastewater discharges. Of lakes not directly affected by point sources, there is a clear separation in mercury accumulation rates between lakes with no/little watershed development and lakes with extensive watershed development for agricultural and/or residential purposes. Lakes in the latter group exhibited a sharp increase in mercury accumulation rates with human settlement, stabilizing after 1950 at five times (5×) 1850 rates. Mercury accumulation rates in lakes with no/little watershed development were controlled primarily by relative watershed size prior to 1850, and since have exhibited modest increases (in absolute terms and compared to that described above) associated with (regional and global) industrialization. A sub-regional analysis highlighted that in the ecoregion Northwestern Forest Mountains, <1% of mercury deposited to watersheds is delivered to lakes. Research is warranted to understand whether mountainous watersheds act as permanent sinks for mercury or if export of "legacy" mercury (deposited in years past) will delay recovery when/if emissions reductions are achieved.
University of Michigan Biological Station, 9133 Biological Rd., Pellston, MI 49769, USA; University of Michigan School of Natural Resources and Environment, 440 Church St., Ann Arbor, MI 48109, USA. Electronic address: drevnick@umich.edu.
Paul E
PE
Drevnick
Alberta Environmental Monitoring, Evaluation and Reporting Agency, 10th Floor, 9888 Jasper Avenue NW, Edmonton, AB T5J 5C6, Canada; Department of Earth and Atmospheric Sciences, 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB T6G 2E3, Canada.
Colin A
CA
Cooke
University of Michigan School of Natural Resources and Environment, 440 Church St., Ann Arbor, MI 48109, USA.
Daniella
D
Barraza
Program in Chemical and Environmental Toxicology, Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
Jules M
JM
Blais
Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA.
Kenneth H
KH
Coale
Paleoecological Environmental Assessment and Research Laboratory, Department of Biology, Queen's University, Biosciences Complex, Kingston, ON K7L 3N6, Canada.
Brian F
BF
Cumming
Environmental Change Research Centre, University College London, Gower Street, London WC1E 6BT, UK.
Chris J
CJ
Curtis
Saskatchewan Water Security Agency, 420-2365 Albert St., Regina, SK S4P 4K1, Canada.
Biplob
B
Das
Alberta Environmental Monitoring, Evaluation and Reporting Agency, 10th Floor, 9888 Jasper Avenue NW, Edmonton, AB T5J 5C6, Canada.
William F
WF
Donahue
U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, OR 97331, USA.
Collin A
CA
Eagles-Smith
St. Croix Watershed Research Station, Science Museum of Minnesota, Marine on St. Croix, MN 55047, USA.
Daniel R
DR
Engstrom
Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.
William F
WF
Fitzgerald
Washington State Department of Ecology, Environmental Assessment Program, P.O. Box 47600, Olympia, WA 98504, USA.
Chad V
CV
Furl
U.S. Geological Survey, MS 973, Denver Federal Center, Denver, CO 80225, USA.
John E
JE
Gray
Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
Roland I
RI
Hall
Aquatic Contaminants Research Division, Water Science & Technology Directorate, Environment & Climate Change Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, ON L7R 4A6, Canada.
Togwell A
TA
Jackson
Paleoecological Environmental Assessment and Research Laboratory, Department of Biology, Queen's University, Biosciences Complex, Kingston, ON K7L 3N6, Canada.
Kathleen R
KR
Laird
Department of Fisheries and Oceans, 501 University Crescent, Winnipeg, MB R3T 2N6, Canada.
W Lyle
WL
Lockhart
Department of Fisheries and Oceans, Institute of Ocean Sciences, P.O. Box 6000, Sidney, BC V8L 4B2, Canada.
Robie W
RW
Macdonald
U.S. Geological Survey, Colorado Water Science Center, MS 415, Denver Federal Center, Denver, CO 80225, USA.
M Alisa
MA
Mast
Washington State Department of Ecology, Environmental Assessment Program, P.O. Box 47600, Olympia, WA 98504, USA.
Callie
C
Mathieu
Aquatic Contaminants Research Division, Water Science & Technology Directorate, Environment & Climate Change Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, ON L7R 4A6, Canada.
Derek C G
DCG
Muir
Geological Survey of Canada, 601 Booth Street, Ottawa, ON K1A 0E8, Canada.
Peter M
PM
Outridge
Department of Geography, The Ohio State University, 1036 Derby Hall, 154 North Oval Mall, Columbus, OH 43210, USA.
Scott A
SA
Reinemann
Department of Environmental Health Sciences, University of South Carolina, 921 Assembly Street, Columbia, SC 29208, USA.
Sarah E
SE
Rothenberg
Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Calz. Joel Montes Camarena s/n, CP 82040 Mazatlán, Sinaloa, Mexico.
Ana Carolina
AC
Ruiz-Fernández
Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2R3, Canada.
Vincent L St
VLS
Louis
Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA.
Rhea D
RD
Sanders
Geological Survey of Canada, 3303-33rd Street N.W., Calgary, AB T2L 2A7, Canada.
Hamed
H
Sanei
Program in Chemical and Environmental Toxicology, Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
Elliott K
EK
Skierszkan
U.S. Geological Survey, 1505 Ferguson Lane, Austin, TX 78754, USA.
Peter C
PC
Van Metre
University of Michigan Biological Station, 9133 Biological Rd., Pellston, MI 49769, USA.
Timothy J
TJ
Veverica
Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada.
Johan A
JA
Wiklund
Department of Geography and Environmental Studies, Wilfrid Laurier University, 75 University Avenue West, Waterloo, ON N2L 3C5, Canada.
Brent B
BB
Wolfe
Lake; Mercury; Sediment; Western North America