Hydrocarbons and Fisheries Habitat in Berners Bay, Alaska: Long-term Monitoring Associated With the Kensington Gold Mine
Several projects associated with development of the Kensington Gold Mine have been proposed for the Berners Bay area 65 km north of Juneau Alaska (Fig. 4 below). Construction of two ferry terminals and other related infrastructure may affect as many as 80 hectares (ha) within the Berners Bay watershed. Potential sources of hydrocarbons to the bay include fuel spills, chronic pollution from vessels, and parking lot runoff near the terminal facilities. ABL researchers have documented damage to pink salmon and Pacific herring (Clupea pallasii) embryos by concentrations of polynuclear aromatic hydrocarbons (PAHs) as low as 1 ppb. Both species, as well as eulachon (Thaleichthys pacificus) and capelin (Mallotus villosus), spawn in intertidal areas of the bay. In 2004, AFSC scientists initiated baseline studies in Berners Bay to document hydrocarbon concentrations and fish use of important habitats (e.g., eelgrass and understory kelp) before mine development.
Hydrocarbons were measured using passive samplers developed at ABL called
polyethylene membrane devices (PEMDs). Samplers
were deployed at seven sites in Berners Bay and at two sites in Bridget
Cove, a nearby control site. These devices provide a sample of
bioavailable PAHs in seawater and air integrated over 30 days.
Conventional seawater, sediment, and mussel tissue (Mytilus trossulus)
hydrocarbon samples were also taken at four of the PEMD sites to compare
to state water quality standards for Alaska. Most hydrocarbon
concentrations were at or below minimum instrument detection levels in
PEMDs, seawater, sediment, and mussel tissue, indicating near pristine
conditions in Berners Bay. Total PAH concentrations in all matrices were
below levels considered baseline for Prince William Sound, Alaska: 10 to
100 ng/L for water, 100 ng/g dry wt for sediment, and 90 ng/g dry wt for
mussel tissue. The PAH patterns observed in the PEMDs with the highest
concentrations are consistent with patterns for diesel fuel, and the
higher concentrations coincided with increased commercial fishing in the
By Pat Harris
Southeast Alaska Regional Science Fair
ABL scientists played an integral role in the 2005 Southeast Alaska
Regional Science Fair. The fair, held on 5 March in Juneau, is for high
school students in Southeast Alaska. The fair is affiliated with Intel’s
International Science and Engineering Fair, which is the world’s largest
science fair and has more than $3 million in awards in scholarships.
Scientists from ABL mentored many of the 112 projects entered in this
year’s fair, and 4 of the ABL-mentored projects advanced to the final
round of judging.
By Bonita Nelson