Castello Leandro, Carvalho Felipe, Ateba Nelly Ornelle Onana, Busanga Alidor Kankonda, Ickowitz Amy, Frimpong Emmanuel
Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA USA.
Department of Parasitology and Ecology, University of Yaoundé 1, Yaoundé, Cameroon.
Rev Fish Biol Fish. 2023 Mar 21:1-18. doi: 10.1007/s11160-023-09770-x.
Small-scale fisheries (SSF) account for much of the global fish catch, but data to assess them often do not exist, impeding assessments of their historical dynamics and status. Here, we propose an approach to assess 'data-less' SSF using local knowledge to produce data, life history theory to describe their historical multispecies dynamics, and length-based reference points to evaluate stock status. We demonstrate use of this approach in three data-less SSFs of the Congo Basin. Fishers' recalls of past fishing events indicated fish catch declined by 65-80% over the last half-century. Declines in and depletion of many historically important species reduced the diversity of exploited species, making the species composition of the catch more homogenous in recent years. Length-at-catch of 11 of the 12 most important species were below their respective lengths-at-maturity and optimal lengths (obtained from Fishbase) in recent years, indicating overfishing. The most overfished species were large-bodied and found in the Congo mainstem. These results show the approach can suitably assess data-less SSF. Fishers' knowledge produced data at a fraction of the cost and effort of collecting fisheries landings data. Historical and current data on fish catch, length-at-catch, and species diversity can inform management and restoration efforts to curb shifting baselines of these fisheries. Classification of stock status allows prioritizing management efforts. The approach is easy to apply and generates intuitive results, having potential to complement the toolkits of researchers and managers working in SSF and engage stakeholders in decision-making processes.
The online version contains supplementary material available at 10.1007/s11160-023-09770-x.
小规模渔业（SSF）占全球鱼类捕捞量的很大一部分，但评估它们的数据往往不存在，这阻碍了对其历史动态和现状的评估。在此，我们提出一种方法，利用当地知识生成数据来评估“无数据”的小规模渔业，运用生活史理论描述其历史多物种动态，并使用基于体长的参考点来评估种群状况。我们在刚果盆地的三个无数据小规模渔业中展示了这种方法的应用。渔民对过去捕鱼事件的回忆表明，在过去半个世纪里鱼类捕捞量下降了65% - 80%。许多历史上重要物种的数量减少和枯竭降低了被捕捞物种的多样性，使得近年来渔获物的物种组成更加单一。近年来，12种最重要物种中的11种的捕捞体长低于其各自的成熟体长和最佳体长（从Fishbase获取），这表明存在过度捕捞。过度捕捞最严重的物种体型较大，分布在刚果河主干道。这些结果表明该方法能够适当地评估无数据的小规模渔业。渔民的知识以收集渔业上岸数据所需成本和精力的一小部分生成了数据。关于鱼类捕捞量、捕捞体长和物种多样性的历史和当前数据可为管理和恢复工作提供信息，以遏制这些渔业不断变化的基线。种群状况分类有助于确定管理工作的优先次序。该方法易于应用且产生直观的结果，有可能补充从事小规模渔业研究的人员和管理人员的工具包，并促使利益相关者参与决策过程。
在线版本包含可在10.1007/s11160 - 023 - 09770 - x获取的补充材料。
