By Thomas P. Quinn, B. A. Terhart, C. Groot
Animal Behaviour, Volume 37, Part 4, April 1989, Pages 587-599, ISSN 0003-3472, DOI: 10.1016/0003-3472(89)90038-9.

Adult sockeye salmon returning to the Fraser River, British Columbia, were tracked with depthsensing ultrasonic transmitters to study the factors guiding their homing migration in coastal waters. The salmon generally swam in either the homeward direction (east southeast) or the opposite direction. When sockeye salmon encountered obstacles such as islands or peninsulas, they did not follow the shoreline but rather swam back out into open water, turned and resumed their original orientation. Sockeye generally occupied the upper 30 m of the water column but significant variation in depth of travel between regions with different oceanographic characteristics was observed. Depth of travel seemed to be controlled by a general preference for the surface, avoidance of warm (also low salinity) water, and orientation to the thermocline.

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