COLONIZATION OF A VIRGIN SHORELINE IN PRINCE WILLIAM SOUND, 2000 TO 2007, COMPARED TO RECOVERY OF OILED AND CLEANED SHORELINES

摘要

A new landslide-created shoreline in Prince William Sound offered an opportunity to monitor colonization of virgin rock and to compare that colonization with that of nearby oiled and cleaned sites monitored during the early 1990's. The intertidal zone of six well-separated vertical landslide surfaces were photographed annually from 2001 to 2007 and the photos used to estimate changes in cover of conspicuous intertidal seaweeds. Colonization by rockweed (Fucus sp.) was rapid and by 2003 appeared to converge with density comparable to adjacent undisturbed (control) shoreline. Percent cover of Fucus declined in 2005, then increase again in 2006 and 2007. This pattern of evolving zonation, and rapid increase and then decrease in Fucus cover, was nearly identical to the patterns observed at oiled and cleaned sites in the early 1990's suggesting that what was seen then was an entirely normal process of intertidal colonization. Additional monitoring would be useful to determine (1) the development of the supra-littoral black lichen (Verrucaria) zone and (2) if variation in the cover, patchiness and zonation at the landslide sites parallels the longterm variation at reference sites.