Thermal heterogeneity, migration, and consequences for spawning potential of female bull trout in a river–reservoir system
| Autor: | Joseph R. Benjamin, Dmitri Vidergar, Jason B. Dunham |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Bioenergetics Energy reserves spawning bioenergetics migration 010603 evolutionary biology 01 natural sciences Reservoir system 03 medical and health sciences lcsh:QH540-549.5 Ecology Evolution Behavior and Systematics reproductive and urinary physiology Original Research 030304 developmental biology Nature and Landscape Conservation 0303 health sciences Ecology biology urogenital system energy content fungi temperature biology.organism_classification Spawn (biology) Salvelinus confluentus Spatial heterogeneity Fishery Trout Boise River Energy density lcsh:Ecology |
| Zdroj: | Ecology and Evolution, Vol 10, Iss 9, Pp 4128-4142 (2020) Ecology and Evolution |
| ISSN: | 2045-7758 |
| Popis: | The likelihood that fish will initiate spawning, spawn successfully, or skip spawning in a given year is conditioned in part on availability of energy reserves. We evaluated the consequences of spatial heterogeneity in thermal conditions on the energy accumulation and spawning potential of migratory bull trout (Salvelinus confluentus) in a regulated river–reservoir system. Based on existing data, we identified a portfolio of thermal exposures and migratory patterns and then estimated their influence on energy reserves of female bull trout with a bioenergetics model. Spawning by females was assumed to be possible if postspawning energy reserves equaled or exceeded 4 kJ/g. Given this assumption, results suggested up to 70% of the simulated fish could spawn each year. Fish that moved seasonally between a cold river segment and a warmer reservoir downstream had a greater growth rate and higher propensity to spawn in a given year (range: 40%–70%) compared with fish that resided solely in the cold river segment (25%–40%). On average, fish that spawned lost 30% of their energy content relative to their prespawn energy. In contrast, fish that skipped spawning accumulated, on average, 16% energy gains that could be used toward future gamete production. Skipped spawning occurred when water temperatures were relatively low or high, and if upstream migration occurred relatively late (mid‐July or later) or early (early‐May or earlier). Overall, our modeling effort suggests the configuration of thermal exposures, and the ability of bull trout to exploit this spatially and temporally variable thermal conditions can strongly influence energy reserves and likelihood of successful spawning. We evaluated the consequences of spatial heterogeneity in thermal conditions on the energy accumulation and spawning potential of migratory bull trout (Salvelinus confluentus) in a regulated river–reservoir system. Overall, our modeling effort suggests the configuration of thermal exposures and the ability of bull trout to exploit this spatially and temporally variable thermal conditions can strongly influence energy reserves and likelihood of successful spawning. |
| Databáze: | OpenAIRE |
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