Will you swim into my parlour? In situ observations of Atlantic cod (Gadus morhua) interactions with baited pots, with implications for gear design

PeerJ. 2017 Feb 8:5:e2953. doi: 10.7717/peerj.2953. eCollection 2017.

Abstract

Pots (also known as traps) are baited fishing gears widely used in commercial fisheries, and are being considered as a tool for harvesting Atlantic cod (Gadus morhua) in Newfoundland and Labrador, Canada. Pots produce lower environmental impacts than many other fishing gears, but they will only be a viable fishing strategy if they are efficient and selective at catching their target species. To study the behaviour of cod in and around pots, and how those behaviours affect pot efficiency, we used long-duration underwater video cameras to assess two models of cod pot deployed in the nearshore waters of Fogo Island, NL. We examined the number of cod that approached the pot, the number and proportion that successfully completed entries into the pot openings, and the number that exited, and related these factors to the direction of water movement. We observed very few entry attempts relative to the number of approaches by cod, and only 22% of all entry attempts were successful. We observed that 50% of approaches, 70% of entry attempts, and 73% of successful entrances occurred against the current, and 25% of cod were able to exit the pot following capture. Based on our observations, we suggest that future cod pots should have a greater number of entrances, or a mechanism to ensure that entrances rotate in line with the current, in order to maximize their catch efficiency for cod.

Keywords: Atlantic cod; Behaviour; Behavioural ecology; Conservation; Fisheries; Fishing gear; Marine biology; Newfoundland; Sustainability; Underwater video.

Grants and funding

Financial support for this project was provided by the Canadian Centre for Fisheries Innovation (H-2015-08), the Research and Development Corporation of Newfoundland and Labrador’s Ignite program (5404.1889.101) and Ocean Industry Student Research Award (5404-1911-101), Fisheries and Oceans Canada (F5211-150224), a Marine Environmental Observation Prediction and Response (MEOPAR) Early Career Faculty Research Award (EC1-BF-MUN), and the Liber Ero Fellowship. In-kind support was provided by inshore fish harvesters of Fogo Island, including Aubrey and Marie Payne, and Rodney Button. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.