title: Rearing in a distorted magnetic field disrupts the 'map sense' of juvenile steelhead trout.
abstract: We used simulated magnetic displacements to test orientation preferences of juvenile steelhead trout (Oncorhynchus mykiss) exposed to magnetic fields existing at the northernmost and southernmost boundaries of their oceanic range. Fish reared in natural magnetic conditions distinguished between these two fields by orienting in opposite directions, with headings that would lead fish towards marine foraging grounds. However, fish reared in a spatially distorted magnetic field failed to distinguish between the experimental fields and were randomly oriented. The non-uniform field in which fish were reared is probably typical of fields that many hatchery fish encounter due to magnetic distortions associated with the infrastructure of aquaculture. Given that the reduced navigational abilities we observed could negatively influence marine survival, homing ability and hatchery efficiency, we recommend further study on the implications of rearing salmonids in unnatural magnetic fields.
authors.affiliation: Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97331, USA National Marine Fisheries Service, Southeast Fisheries Science Center, Miami, FL 33149, USA nathan.putman@gmail.com.
authors.forename: Nathan F
authors.initials: NF
authors.lastname: Putman
authors.affiliation: Oregon Hatchery Research Center, Oregon Department of Fish and Wildlife, Alsea, OR 97324, USA.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Meinke
authors.affiliation: Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97331, USA Oregon Hatchery Research Center, Oregon Department of Fish and Wildlife, Alsea, OR 97324, USA.
authors.forename: David L G
authors.initials: DL
authors.lastname: Noakes
mesh_terms: D025041:Animal Migration; D000818:Animals; D017756:Aquaculture; D060328:Magnetic Phenomena; D017686:Oncorhynchus mykiss / Q000502:physiology*
keywords: magnetic map; navigation; salmon; trout