Response of the Dominant Alga Fucus gardneri (Silva) (Phaeophyceae) to the Exxon Valdez Oil Spill and Clean-up

The Coastal Habitat Injury Assessment Study was initiated to assess injury to and recovery of intertidal habitats affected by the Exxon Valdez oil spill, 1989, and subsequent clean-up. The spill area was divided into three major regions: Prince William Sound (PWS), Cook Inlet-Kenai (CIK) and Kodiak–Alaska Peninsula (KAP) and distinct habitat types within the area. The dominant intertidal macrophyte, Fucus gardneri, was impacted over the entire area of the spill, although observed differences varied across regions, habitats, and tidal heights. Generally F. gardneri biomass and percent cover were reduced in most habitats. However, at the low intertidal in CIK sheltered rocky habitat, the F. gardneri population was enhanced at the expense of annuals. Thalli of F. gardneri at oiled sites were not as reproductively competent as those at reference sites. Population structures were also altered. A greater proportion of adult F. gardneri thalli had attached epiphytes in oiled sites. Additional data collected during 1992–1994, indicate varying rates of recovery for F. gardneri populations