Burbank Jacob, Rolland Nicolas, McDermid Jenni L, Turcotte François, Tunney Tyler D, Ricard Daniel, Sylvain François-Étienne
Fisheries and Oceans Canada, Gulf Fisheries Centre, Moncton, NB, Canada.
Commun Biol. 2025 May 30;8(1):831. doi: 10.1038/s42003-025-08240-3.
Profound changes in species assemblages are occurring in marine ecosystems worldwide and are essential to document. Here we use 51 years (1971-2021) of fishery-independent data from a standardized bottom-trawl research vessel survey (6440 independent fishing locations) in the southern Gulf of St. Lawrence covering 70,091 km² to evaluate trends in marine community structure and trawlable biomass across 122 fish and crustacean taxa. Survey data indicate a substantial decline in biomass and increase in turnover for taxa susceptible to bottom-trawl fishing gear in the southern Gulf of St. Lawrence marine ecosystem that corresponds with the reduction of several predatory fish and a major regime shift around the early 1990's. Unlike other marine regime shift examples, we observe a substantial net loss of trawlable biomass in the community, with limited compensatory response in small fish and crustacean biomass over nearly 30 years following the depletion of predatory groundfish. Overall, this unique case of reduced biomass and shift in community structure highlights the importance of maintaining and analyzing fishery-independent surveys over extended time series. Such information is vital to assessing the state of marine ecosystems and developing plans for recovery, as we face a future of untold challenges in managing marine ecosystems worldwide.
全球海洋生态系统中物种组合正在发生深刻变化，记录这些变化至关重要。在此，我们利用来自圣劳伦斯湾南部一艘标准化底拖网研究船调查的51年（1971 - 2021年）独立于渔业的数据（6440个独立捕捞地点），覆盖面积达70,091平方千米，以评估122种鱼类和甲壳类分类群的海洋群落结构和可拖网生物量的趋势。调查数据表明，圣劳伦斯湾南部海洋生态系统中，易受底拖网渔具影响的分类群生物量大幅下降，周转率增加，这与几种掠食性鱼类数量减少以及20世纪90年代初左右的一次重大生态系统转变相对应。与其他海洋生态系统转变的例子不同，我们观察到群落中可拖网生物量出现了显著的净损失，在掠食性底层鱼类枯竭后的近30年里，小型鱼类和甲壳类生物量的补偿性反应有限。总体而言，这种生物量减少和群落结构转变的独特案例凸显了在长时间序列上维持和分析独立于渔业的调查的重要性。这些信息对于评估海洋生态系统的状态以及制定恢复计划至关重要，因为在全球范围内管理海洋生态系统时，我们面临着无数未知的挑战。
