Re-Assessment of Bivalve Recovery on Treated Mixed-Soft Beaches In Prince William Sound, Alaska: 2010

National Oceanic and Atmospheric Administration treatment effects studies from 1989 through 1997 suggested that bivalve assemblages on beaches in Prince William Sound treated with high-pressure washing were severely injured in terms of abundance, species composition, and function. Restoration Project 040574 assessed the generality and persistence of this apparent injury to this assemblage. Sites were re-assessed in 2010 to test for long term effects of treatment. The major purposes of this study were to monitor recovery and compare bivalve abundance patterns to those observed in 2002. As such, the 39 sites occupied during this study were specifically those sampled in the EVOS TC 2002 study (Lees and Driskell 2007). GPS coordinates and site photographs from the 2002 study were used to reoccupy the same area to the degree allowable by tide levels at the time of sampling. One site, Northwest Bay West Arm, was deleted from this suite of sites on the understanding that NOAA would sample it during a complementary study. That site ultimately was not sampled. The data here represent the bivalve survey results from these assessments. Note: This is an assessment of the bivalves, although various non-bivalve species are included in both data sets. These species were excluded from any of the analyses under this project but are available here for further analysis. Additionally, although mussel Mytilus trossulus are included in both data sets, this species was also excluded from any of the analyses as it is an epifaunal organism that would only confuse analyses of the infaunal bivalves. (EVOS Recovery project 10100574)