Analysis of straying variation in Alaskan hatchery chinook salmon (Oncorhynchus tshawytscha) following transplantation

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 56; no. 4; pp. 578 - 589
• Main Authors: Hard, Jeffrey J, Heard, William R
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.04.1999; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Fish; Fish hatcheries; Fish migration; Fish stocking; Freshwater; Fundamental and applied biological sciences. Psychology; Marine; Oncorhynchus tshawytscha; Rivers; Salmon; Vertebrata; Canada; Alaska; British Columbia; United States; North America; America; USA, Alaska, Baranof I., Little Port Walter; Salmonidae; Oncorhynchus tshawytscha; Residence time; Sex; Population translocation; Hatchery; Multiyear variation; Freshwater environment; Marine environment; Homing; Vertebrata; Follow up study; Pisces; Stream; Animal population; Age
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/f98-199

In 1976 chinook salmon (Oncorhynchus tshawytscha) gametes from the Chickamin and Unuk rivers in southeastern Alaska were transplanted 250 km to establish hatchery runs at Little Port Walter (LPW), Baranof Island. From 1977 to 1989, 1 862 058 marked smolts from 12 broods were released from LPW. Homing and straying were estimated from adult recoveries at 25 locations in Alaska and British Columbia between 1981 and 1989. Of 22 198 LPW fish recovered over this period, 21 934 (98.8%) were collected at LPW. Of 264 fish recovered elsewhere, 38.3% were within 7 km of LPW; 64.4% were within 25 km of LPW. No LPW fish were recovered from the ancestral rivers, but nine fish were recovered from rivers supporting wild chinook salmon. Straying declined with distance from the release site but varied between hatcheries and streams. Straying declined with increasing age and run size. Straying was similar between the populations but varied among broods, and analysis of straying in experimental groups provided evidence for a heritable component. Males strayed more often than females. Population, gender, run size, and recovery age interacted to produce substantial variation in straying, indicating that run composition can produce complex straying responses.