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.
Bibliographical noteFunding Information:
Funding was provided by the National Park Service , the Univ. Alaska Southeast , and the U.S. National Science Foundation (EAR- 0838587 ). Thanks to J. Smith of R/V Capelin for transport in GBNPP and N. Schlosstein for field assistance. K. Smikrud provided Fig. 1 . We thank K. Butler at the USGS in Boulder, CO for characterization of DOC. Thanks to ME Brigham and three anonymous reviewers for improving the manuscript. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.