title: Spatial distribution of mercury in southeastern Alaskan streams influenced by glaciers, wetlands, and salmon.
abstract: Southeastern Alaska is a remote coastal-maritime ecosystem that is experiencing increased deposition of mercury (Hg) as well as rapid glacier loss. Here we present the results of the first reported survey of total and methyl Hg (MeHg) concentrations in regional streams and biota. Overall, streams draining large wetland areas had higher Hg concentrations in water, mayflies, and juvenile salmon than those from glacially-influenced or recently deglaciated watersheds. Filtered MeHg was positively correlated with wetland abundance. Aqueous Hg occurred predominantly in the particulate fraction of glacier streams but in the filtered fraction of wetland-rich streams. Colonization by anadromous salmon in both glacier and wetland-rich streams may be contributing additional marine-derived Hg. The spatial distribution of Hg in the range of streams presented here shows that watersheds are variably, yet fairly predictably, sensitive to atmospheric and marine inputs of Hg.
authors.affiliation: Environmental Science Program, University of Alaska Southeast, Juneau, AK 99801, USA. Electronic address: sanagorski@uas.alaska.edu.
authors.forename: Sonia A
authors.initials: SA
authors.lastname: Nagorski
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Engstrom
authors.forename: John P
authors.initials: JP
authors.lastname: Hudson
authors.forename: David P
authors.initials: DP
authors.lastname: Krabbenhoft
authors.forename: Eran
authors.initials: E
authors.lastname: Hood
authors.forename: John F
authors.initials: JF
authors.lastname: DeWild
authors.forename: George R
authors.initials: GR
authors.lastname: Aiken
mesh_terms: D000413:Alaska; D000818:Animals; D058448:Biota; D017753:Ecosystem; D004784:Environmental Monitoring; D046448:Ice Cover / Q000737:chemistry*; D008628:Mercury / Q000032:analysis* / Q000378:metabolism; D008767:Methylmercury Compounds / Q000032:analysis / Q000378:metabolism; D045483:Rivers / Q000737:chemistry*; D012474:Salmon / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism; D053833:Wetlands
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: DOC; Deglaciation; Macroinvertebrates; Mercury; Salmon; Wetland