Validation of daily increments and a marine‐entry check in the otoliths of sockeye salmon Oncorhynchus nerka post‐smolts |
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| Authors: | C. Freshwater M. Trudel T. D. Beacham C.‐E. Neville S. Tucker F. Juanes |
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| Affiliation: | 1. Department of Biology, University of Victoria, Victoria, BC, V8W 3N5, Canada;2. Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, BC, V9T 6N7, Canada |
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| Abstract: | Juvenile sockeye salmon Oncorhynchus nerka that were reared and smolted in laboratory conditions were found to produce otolith daily increments, as well as a consistently visible marine‐entry check formed during their transition to salt water. Field‐collected O. nerka post‐smolts of an equivalent age also displayed visible checks; however, microchemistry estimates of marine‐entry date using Sr:Ca ratios differed from visual estimates by c. 9 days suggesting that microstructural and microchemical processes occur on different time scales. |
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| Keywords: | age validation marine entry otolith microchemistry otolith microstructure |
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