Glacier Bay National Park and Preserve (GBNPP), like many pristine high-latitude areas, is currently at risk from atmospherically derived contaminants such as Hg. Although the harmful effects of Hg are well established, information on this pollutant in southeast Alaska is scarce. We investigated Hg dynamics in three adjacent, small streams in GBNPP draining contrasting landscapes yet receiving the same atmospheric inputs. We assessed the level of this contaminant in several aquatic components (water, sediments, and biological tissue), tracked aqueous concentrations over variable seasonal conditions, and evaluated differences among watersheds.
Discharge was measured and water samples were collected on 20 occasions over the course of 2 years and processed and analyzed for total and methylmercury (both filtered and particulate), dissolved organic carbon quanity and quality, and ancillary stream water parameters (pH, dissolved oxygen, specific conductance, and temperature). Major cations and anions were measured on four sampling events. Mercury was analyzed in streambed sediment on one event, and in juvenile coho salmon and several taxa of benthic macroinvertebrates during the early summer of both study years.
