Centre for Sustainable Aquatic Resources, Fisheries and Marine Institute, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada.
PeerJ. 2023 Oct 16;11:e16244. doi: 10.7717/peerj.16244. eCollection 2023.
In this study, we developed a semi-pelagic trawl to target redfish ( spp.) and potentially reduce the capture of bycatch species and seabed impacts in the Gulf of St. Lawrence, Canada. The new trawl used an innovative technique connecting the upper bridles of the trawl to the warps, anterior of the trawl doors, leading to the trawl system being fished off the seabed. Such a technique can be used to match the heights of redfish as they move above the seabed during their diurnal cycle while allowing bycatch species related to the seabed to escape under the trawl. A 1:10 scale model of the trawl was constructed and evaluated in a flume tank to optimize the rigging and then a full-scale trawl was constructed for sea trials. Two field experiments subsequently evaluated the trawl at sea. The first field experiment concentrated on the experimental trawl's operation and video observations of redfish behaviour in the trawl mouth and its effect on trawl entry. The second field experiment concentrated on a small-scale preliminary test on the catch of redfish and bycatch species when the trawl was on or off the seabed. Capture results, though preliminary, indicate that redfish can be targeted commercially with a semi-pelagic trawl, though some redfish will escape under the trawl. Additionally, results suggest that the catches of bycatch species may be reduced. In conclusion, this study suggests that a semi-pelagic trawl could be considered an effective technique to harvest redfish sustainably.
在这项研究中，我们开发了一种半洄游拖网，旨在捕捞红点鲑（ spp.），并有可能减少在加拿大圣劳伦斯湾的兼捕物种和海底影响。新的拖网使用了一种创新的技术，将拖网的上挽具连接到拖网门的前缘的绞纲上，导致拖网系统在海底以外的地方捕鱼。这种技术可以用来匹配红点鲑在其昼夜周期中在海底上方移动时的高度，同时允许与海底有关的兼捕物种在拖网下逃脱。我们构建了一个 1:10 比例的拖网模型，并在水槽中进行了评估，以优化装备，然后建造了一个全尺寸的拖网进行海上试验。随后进行了两项海上试验来评估该拖网。第一项现场试验集中在实验拖网的操作和红点鲑在拖网口中的行为的视频观察及其对拖网进入的影响上。第二项现场试验集中在拖网在海底或离开海底时对红点鲑和兼捕物种的小规模初步捕捞测试上。尽管初步的捕获结果表明，红点鲑可以用半洄游拖网进行商业捕捞，但有些红点鲑会从拖网下逃脱。此外，结果表明兼捕物种的捕获量可能会减少。总之，本研究表明，半洄游拖网可以被视为一种可持续捕捞红点鲑的有效技术。
