1. Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA 93950, USA
2. Institute of Marine Sciences, University of California, Santa Cruz, CA 95064, USA
3. Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Monterey, CA 93950, USA
4. Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
5. Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA 94305, USA