Kenneth F. Tiffan
John M. Erhardt
2018
<p><span>Release of age‐0 hatchery‐reared fall Chinook salmon, </span><i>Oncorhynchus tshawytscha</i><span>(Walbaum), in the Snake River resulted in up to 30‐fold increases in salmon consumption by non‐native smallmouth bass, </span><i>Micropterus dolomieu</i><span> Lacepѐde. In an upper river reach, smallmouth bass fed intensively during a release in May, but Chinook salmon consumption returned to pre‐release levels within 1–2 days as hatchery‐reared fish quickly emigrated downstream. The predation response during a June release located farther downstream was dissimilar. Chinook salmon consumption increased to a lesser extent (11‐fold), lasted several days (~4) and no changes in feeding intensity were evident. Estimated numbers of age‐0 hatchery‐reared Chinook salmon lost to short‐term predation varied by year and study reach and ranged from 12,007 (6.03% of those released) to 210,580 (14.6% of those released) fish. Short‐term, intense feeding by smallmouth bass can contribute significantly to mortality of hatchery‐reared fish and should be considered when supplementing populations with hatchery juveniles.</span></p>
application/pdf
10.1111/fme.12322
en
Wiley
Post‐release predation mortality of age‐0 hatchery‐reared Chinook salmon from non‐native smallmouth bass in the Snake River
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