Mobile bottom fishing in the Canadian Pacific and Atlantic causes disturbance and risk to remineralisation of seabed sediment carbon stocks

Canadian Journal of Fisheries and Aquatic Sciences, Journal Year: 2025, Volume and Issue: 82, P. 1 - 22

Published: Jan. 1, 2025

Mobile bottom fishing causes substantial disturbances to seabed sediments–one of the world’s largest organic carbon stores. We estimate that 2.1 and 32.0 Mt is disturbed by annual activities in Canadian Pacific Atlantic, respectively. A net increase remineralisation from this disturbance could negatively impact oceanic sink for CO 2 . Due high uncertainty estimating scale remineralisation, we construct a semiquantitative measure relative risk describe potential differences between locations fisheries. In Pacific, shrimp trawling caused total risk; groundfish had large but lowest mean per unit effort (PUE); scallop dredging smallest impacts highest PUE. dominated impacts; however, PUE was clam dredging, trawling. High spatial variation these results would allow targeted management approach. While uncertainties remain, precautionary risk-based ecosystem should be implemented.

Language: Английский

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Novel computer vision tools applied to marine recreational fisheries spatial planning

Fisheries Research, Journal Year: 2024, Volume and Issue: 271, P. 106924 - 106924

Published: Jan. 2, 2024

Successful marine spatial planning relies on understanding patterns of human use, with accurate, detailed, and up-to-date information about the distribution fishing effort. In commercial vessels, tracking systems like vessel monitoring system (VMS) or automatic identification (AIS) have helped to maintain enhance biodiversity areas by generating large sources positional data that served for planning. However, there is no regulation regarding location such as VMS AIS recreational boats. Obtaining can be difficult time-intensive given widespread variable nature fleet. Remote cameras computer vision are increasingly used overcome cost limitations these conventional methods. Here we show a novel high-resolution low-cost based photo time-lapses state-of-the-art algorithms, including deep learning, automatically classify obtain precise trajectories cruising boats in coastal areas. Our method contributes surveillance protected providing an image-based tool automatic, real-time monitoring. also allows determining intensity spatial-temporal effort, important defining sustainability activity We finally discuss opportunities tools applied fisheries

Language: Английский

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Application of AIS‐ and flyover‐based methods to monitor illegal and legal fishing in Canada's Pacific marine conservation areas

Conservation Science and Practice, Journal Year: 2023, Volume and Issue: 5(6)

Published: April 2, 2023

Abstract New approaches are required to undertake the substantial task of monitoring ongoing fishing activity in marine conservation areas ensure goals achieved. To address this need, we applied previously developed, yet currently underused, vessel tracking methods based on Automatic Identification System (AIS) and aerial surveillance (“flyovers”) Canada's Pacific from 2012 2019. We used satellite terrestrial‐based AIS receivers flyover‐based visual observations estimate illegal legal after 185 area (CA) enactments (i.e., static, geographically defined with regulations). compared effectiveness detecting between AIS‐ methods, latter determine that 93% vessels were actively CAs without AIS. The AIS‐based method still detected 3303 h enactment, both estimated 22%–24% was illegal. application these also shed light complexity regulations across varying CA‐specific restrictions). This highlighted need better align gear classifications CA regulation specifications, conversely simplify (e.g., no‐take), for more accurate evaluation moving forward.

Language: Английский

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Fishing damage to cloud sponges may lead to losses in associated fish communities in Pacific Canada

Marine Environmental Research, Journal Year: 2024, Volume and Issue: 197, P. 106448 - 106448

Published: March 12, 2024

Glass sponge gardens are important biogenic habitats that support fish communities in Pacific Canada. However, glass sponges (class Hexactinellida) delicate and susceptible to damage from fishing gear such as downriggers. In this study we document changes a community before –and after presumed event resulted reduction of 58.9% the available habitat small cloud garden British Columbia. This loss coincided with decline 76.9% relative abundance rockfish, an economically group fishes, at garden. was particularly pronounced size classes disappearance juvenile rockfish loss. Although based on single site, is first documentation how anthropogenic aggregation may impact associated community. Damage likely most aggregations, like nearshore gardens, where result disproportionately large habitat. Slow regrowth suggests availability be permanently altered these sites can coincide shifts localized long lasting local scale. Currently do not have any direct spatial protections Northwest, work highlights importance considering them future protection initiatives.

Language: Английский

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