Figure 2. Longterm trends in the amount (per cent cover) of the seaweed, fucus gardneri, at three categoriesof middle intertidal rocky shoreline sites in Prince William Sound, Alaska, 1989 through 1996. Category 1, unoiled sites； Category 2, oil but untreated sites； and, Category 3, oiled and high-pressure, hot-water washed sites. Dashed lines indicate the range of variation at unoiled sites. NOAA HazMat data in press, 1997.
