, Volume 137, Issue 3, pp 243-248

Evidence for celestial and magnetic compass orientation in lake migrating sockeye salmon fry

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Summary

  1. Radially symmetrical, four-armed tanks were designed for testing the directional preferences of sockeye salmon (Oncorhynchus nerka) fry as they commenced up-lake migrations following emergence from gravel nests and river migration to the lake.

  2. When tested during the day or night, as appropriate for their migration, fry from two different stocks moved in compass directions corresponding to the directions which they would have to maintain in their up-lake migration.

  3. The directional preferences of one population tested during the non-migratory time of day apparently corresponded to the fry's onshore movement.

  4. Orientation was maintained under both overcast and clear skies, and under plastic covers as well. A 90° counter-clockwise shift in the horizontal component of the earth's magnetic field was associated with approximately 90° changes in the mean direction of movement of fry at night, even when they were given a view of the sky. During the day, only fish tested in covered tanks displayed redirected movements in the altered field; those tested with a view of the sky showed geographically appropriate movement patterns despite the shifted field.

Presented at the annual meeting of the American Society of Ichthyologists and Herpetologists, Orono, Maine, in August. 1979
I thank Dr. Ernest Brannon, whose knowledge of sockeye salmon biology and encouragement were essential in carrying out the study. Dr. Ronald Merrill provided valuable advice and criticism, especially concerning the theory and design of magnetic field altering equipment. Asko Hamalainen of the University of Washington's Fisheries Research Institute, and Clarence Miller and Forrest Scott of the International Pacific Salmon Fisheries Commission assisted with the fry collection and field work. Funds were provided by the Washington Sea Grant Program under the National Oceanic and Atmospheric Administration, U.S. Department of Commerce to Dr. Brannon. Drs. Brannon, Merrill and Theodore Pietsch criticized the manuscript.