Prince william sound intertidal biota seven years later: Has it recovered?

Abstract

Eight years of quantitative biological and chemical data have been analyzed for trends in recovery of biota inhabiting beaches in Prince William Sound following the 1989 Exxon Valdez oil spill and subsequent shoreline treatments. Sampling has focused on biota at sheltered rocky and mixed-soft sites subjected to three degrees of disturbance (unoiled, oiled but not hot-water washed, and oiled/hot-water washed). Only epibiota on sheltered rocky habitats are covered in this paper. The majority of community dominants survived 1989 on oiled rocky shores that were not high-pressure, hot-water washed. These areas appeared to be nearly completely recovered by 1991, although subsequent monitoring has revealed oscillations in species abundances that exceed those on unoiled beaches. Hot-water treatments used in 1989 had severe short-term impacts on intertidal epibenthos. Some high-pressure, hot-water-treated rocky shores stripped of biota in 1989 showed very slow colonization through 1995; other areas that appeared to be nearly recovered in 1992 suffered severe declines in dominant taxa in 1995. The dominant age class of rockweed, which began life following hot-water treatment, matured in 1993 and died off in 1994 and 1995, resulting in declines of associated fauna. A new cycle of rockweed colonization has begun, and some recovery of rockweed and associated fauna was observed in 1996.