Thermal regime, predation danger and the early marine exit of sockeye salmon Oncorhynchus nerka. Issue 1 (12th December 2014)

• Record Type: Journal Article
• Authors: Katinic, P. J.; Patterson, D. A.; Ydenberg, R. C.
• Is Part Of: Journal of fish biology. Volume 86:Issue 1(2015)
• Page Start: 276
• Page End: 287
• Publication Date: 2014-12-12
• Subjects: Fishes -- Periodicals; Fishes -- Great Britain -- Periodicals; 597
• DOI: 10.1111/jfb.12596
• Languages: English
• ISSNs: 0022-1112

Abstract

<abstract abstract-type="main" id="jfb12596-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p id="jfb12596-para-0001">Marine exit timing of sockeye salmon <italic>Oncorhynchus nerka</italic> populations on the Haida Gwaii Archipelago, British Columbia, Canada, is described, with specific focus on Copper Creek. Marine exit in Copper Creek occurs &gt; 130 days prior to spawning, one of the longest adult freshwater residence periods recorded for any <italic>O. nerka</italic> population. Copper Creek presents an easy upstream migration, with mild water temperatures (7 to 14° C), short distance (13·1 km) and low elevation gain (41 m) to the lake where fish hold prior to spawning. An energetic model estimates that &lt;1% of the initial energy reserve is required for upstream migration, compared with 62% for lake holding and 38% for reproductive development. Historical records suggest that it is unlikely that water temperature in any of the <italic>O.nerka</italic> streams in Haida Gwaii has ever exceeded the presumed temperature threshold (19° C) for early marine exit. Although it is not impossible that the thermal tolerance of Copper Creek <italic>O.nerka</italic> is very low, the data presented here appear inconsistent with thermal avoidance as an explanation for the early marine exit timing in Copper Creek and in three other populations on the archipelago with early marine exit.</p> </abstract>