1. Williams College, Williamstown, MA 01267, USA.
2. Williams College, Mystic Seaport Maritime Studies Program, Mystic, CT 06355, USA.
3. Department of Fisheries and Wildlife, Oregon State University, Hatfield Marine Science Center, Newport, OR 97365, USA.
4. Moss Landing Marine Laboratories, Moss Landing, CA 95039, USA.
5. Oregon Institute of Marine Biology, Charleston, OR 97420, USA.
6. Smithsonian Environmental Research Center, Edgewater, MD 21037, USA.
7. Department of Environmental Science and Management, Portland State University, Portland, OR 97207, USA.