Adult Atlantic salmon have a new freshwater predator
| Autor: | Stéphanie Boulêtreau, Adeline Gaillagot, Laurent Carry, Stéphane Tétard, Eric De Oliveira, Frédéric Santoul |
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| Rok vydání: | 2017 |
| Předmět: |
Salmo salar
lcsh:Medicine Predation Fresh Water Catfish Transportation Civil Engineering Geographical Locations Salmon Animals lcsh:Science Catfishes Ecosystem Behavior Ecology Animal Behavior lcsh:R Ecology and Environmental Sciences Organisms Biology and Life Sciences Eukaryota Transportation Infrastructure Trophic Interactions Freshwater Fish Europe Fish Community Ecology Osteichthyes Predatory Behavior Vertebrates People and Places Canals Engineering and Technology lcsh:Q Animal Migration Zoology Research Article |
| Zdroj: | PLoS ONE PLoS ONE, Vol 13, Iss 4, p e0196046 (2018) |
| ISSN: | 1932-6203 |
| Popis: | The Atlantic salmon (Salmo salar) is one of the world's most emblematic freshwater fish. Despite conservation and rehabilitation plans, populations of this species are dramatically declining due to human impacts such as habitat fragmentation, overfishing and water pollution. Owing to their large body size, anadromous adults were historically invulnerable to fish predation during their spawning period migration. This invulnerability has disappeared in Western Europe with the introduction of a new freshwater predator, the European catfish (Silurus glanis). Here we report how adults of Atlantic salmon are predated in the fishway of a large river of SW France, where the delayed and narrow passage created by the structure increases the probability of predator-prey encounter. We assessed predation risk by monitoring salmon and catfish in one fishway of the River Garonne, using video fish-counting from 1993 to 2016. We analysed the predation strategy of catfish using observations made with acoustic camera and RFID telemetry in 2016. Our results demonstrate a high predation rate (35%-14/39 ind.) on salmon inside the fishway during the 2016 spawning period migration. Our results suggest that a few specialized catfish individuals adapted their hunting behaviour to such prey, including their presence synchronized with that of salmon (i.e, more occurrences by the end of the day). Such results suggest that the spread of European catfish will potentially impact migration of anadromous species through anthropized systems. |
| Databáze: | OpenAIRE |
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