Underwater observations of the behaviour of snow crab (Chionoecetes opilio) encountering a shrimp trawl off northeast Newfoundland

•Observations of snow crab interactions with footgear components were evaluated.•54% of crabs observed experienced an encounter with the footgear.•Majority of crabs observed appeared to be aware of the trawl.•Majority of crabs were actively responding/reacting to the approaching threat.•We discuss t...

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Veröffentlicht in:Fisheries research 2014-08, Vol.156, p.9-13
Hauptverfasser: Nguyen, Truong X., Winger, Paul D., Legge, George, Dawe, Earl G., Mullowney, Darrell R.
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Sprache:eng
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Zusammenfassung:•Observations of snow crab interactions with footgear components were evaluated.•54% of crabs observed experienced an encounter with the footgear.•Majority of crabs observed appeared to be aware of the trawl.•Majority of crabs were actively responding/reacting to the approaching threat.•We discuss the impacts of shrimp trawling on the snow crab resource. Trawl-mounted video camera observations were conducted to understand how individual snow crabs (Chionoecetes opilio) interact with the rockhopper footgear components of a traditional inshore shrimp trawl used in Newfoundland and Labrador, Canada. Observations of individual snow crab interactions with different footgear components were recorded and evaluated including their orientation, reaction behaviour (i.e., direction of movement), and nature of encounter (i.e., different types of encounters; duration of encounter, and fate of encounter). The analysis demonstrated that snow crabs were quickly overtaken by the approaching trawl and about 54% of the crabs observed experienced an encounter with the footgear (either disc or spacer/chain). The study also revealed that the majority of the crabs observed appeared to be aware of the trawl and were actively responding and/or reacting to the approaching threat. We discuss the impacts of shrimp trawling on the snow crab resource, further research required to better understand the interactions between snow crab and bottom trawls, as well as potential gear modifications to reduce impacts.
ISSN:0165-7836
1872-6763
DOI:10.1016/j.fishres.2014.04.013