title: An inherited magnetic map guides ocean navigation in juvenile Pacific salmon.
abstract: Migratory marine animals exploit resources in different oceanic regions at different life stages, but how they navigate to specific oceanic areas is poorly understood. A particular challenge is explaining how juvenile animals with no prior migratory experience are able to locate specific oceanic feeding habitats that are hundreds or thousands of kilometers from their natal sites. Although adults reproducing in the vicinity of favorable ocean currents can facilitate transport of their offspring to these habitats, variation in ocean circulation makes passive transport unreliable, and young animals probably take an active role in controlling their migratory trajectories. Here we experimentally demonstrate that juvenile Chinook salmon (Oncorhynchus tshawytscha) respond to magnetic fields like those at the latitudinal extremes of their ocean range by orienting in directions that would, in each case, lead toward their marine feeding grounds. We further show that fish use the combination of magnetic intensity and inclination angle to assess their geographic location. The "magnetic map" of salmon appears to be inherited, as the fish had no prior migratory experience. These results, paired with findings in sea turtles, imply that magnetic maps are phylogenetically widespread and likely explain the extraordinary navigational abilities evident in many long-distance underwater migrants.
authors: Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR 97331, USA. Electronic address: nathan.putman@gmail.com.
authors: Nathan F
authors: NF
authors: Putman
authors: Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR 97331, USA.
authors: Michelle M
authors: MM
authors: Scanlan
authors: Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR 97331, USA.
authors: Eric J
authors: EJ
authors: Billman
authors: Oregon Hatchery Research Center, 2418 East Fall Creek Road, Alsea, OR 97324, USA.
authors: Joseph P
authors: JP
authors: O'Neil
authors: Oregon Hatchery Research Center, 2418 East Fall Creek Road, Alsea, OR 97324, USA.
authors: Ryan B
authors: RB
authors: Couture
authors: School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195, USA.
authors: Thomas P
authors: TP
authors: Quinn
authors: Department of Biology, University of North Carolina, CB #3280, Chapel Hill, NC 27599, USA.
authors: Kenneth J
authors: KJ
authors: Lohmann
authors: Department of Fisheries and Wildlife, Oregon State University, 104 Nash Hall, Corvallis, OR 97331, USA; Oregon Hatchery Research Center, 2418 East Fall Creek Road, Alsea, OR 97324, USA.
authors: David L G
authors: DL
authors: Noakes
mesh_terms: D000375:Aging; D025041:Animal Migration; D000818:Animals; D060328:Magnetic Phenomena; D010140:Pacific Ocean; D012474:Salmon / Q000502:physiology*