作者单位:Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95060 USA[1]Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA[2]Stanford Univ, Hopkins Marine Stn, Pacific Grove, CA 93950 USA[3]Univ Calif Santa Cruz, Dept Ocean Sci, Santa Cruz, CA 95060 USA[4]