PWS Non-Indigenous Species Project

by Joel Kopp & Lianna Jack

Currently, not much is known about the impacts or frequency of aquatic nuisance species at high latitudes. In response to a number of risk factors, the Prince William Sound Regional Citizens Advisory Council (RCAC), in association with the USFWS, conducted a one-year pilot study (1997) to begin to summarize current knowledge about non-indigenous species, and identify risks relevant to Prince William Sound.

Due to tanker traffic associated with the Alyeska Pipeline, Prince William Sound (PWS) and the Port of Valdez receives large volumes (~20 million metric tons) of discharged ballast waters. At least half is segregated ballast (“clean”) which is discharged directly into the Port of Valdez and Prince William Sound. The remaining ballast water is oily, and must be processed through Alyeska Pipeline Service Company’s Ballast Water Treatment Facility before being discharged. This process removes oil, but not organisms.

The traffic in combination with the pristine nature of PWS, puts the area at some risk for invasion, according to the pilot study. This concern is further magnified because a number of West Coast ports where ballast water is collected are invaded by non-indigenous species (NIS). Because the tankers deliver to a select number of destination ports, ballast waters dumped in PWS likely contain the same mixture of organisms. This repeated dosing of the same organisms may strengthen their ability to become established.

Also, Valdez-bound tankers were exempted from Federal legislation passed in 1996 which established a voluntary ballast exchange program for ships entering U.S. waters. Short voyages introduce the possibility of a high NIS survival rate in ballast waters.

After a preliminary literature review, the pilot study identified 10 known non-indigenous species including clams, fish and algae, and many possible other species in Price William Sound. This indicates that invasions have already occurred. Although the sampling found four zooplankton species in the “clean” ballast waters, no known noxious species have been found. Very little plankton was found in the oily ballast waters, and according to Gary Sonnevil, USFWS, few, if any, survive the treatment process.

The RCAC has formed a working group consisting of agency, industry and public stakeholders, and conducted an ANS workshop, as well as retaining the Smithsonian Environmental Research Center to conduct the pilot study. They are currently conducing a more comprehensive two-year study which includes ballast exchange experiments and additional field sampling.

For more information about the project, contact Joel Kopp, project manager, at (907) 835-1940, or be e-mail at kopp@pobox.alaska.net, or Gary Sonnevil, USFWS, at (907) 262-9863.