Count & Biomass of Ochre Sea Stars, Pisaster ochraceus at Hopkins Marine Station

Data on ochre sea stars (Pisaster ochraceus) at three sites on Point Cabrillo (Mussel Point) within the Hopkins Marine Life Refuge in Monterey Bay, California span a 50-year period (Feder 1956, 1959, 1970; Pearse et al. 2009). Howard Feder began the study as part of his Ph. D. dissertation research during 1953-1955. He compared the numbers, sizes, and prey of ochre sea stars at three habitats that differed in wave exposure and prey. He found that the sea stars were much larger at the most exposed site, which was dominated by mussels, than at the other two sites, which had few mussels. The most protected site, with the smallest amount of prey, had the fewest, smallest sea stars. Three decades later, beginning in 1986, a new team of researchers (John S. Pearse, James B. McClintock, and Kenneth E. Vicknair) resumed Feder’s study and found striking changes.