Table_1_Environmental variability and fishing effects on artisanal flatfish fisheries along the Portuguese coast.xlsx

Assessing the effects of fishing activity and environmental variability on fishing species might help to understand their fluctuations and to manage them accordingly. However, despite the increasing number of studies linking fisheries and environmental data, few had a multi-species approach considering flatfish species and different age groups. Therefore, this study aims to determine the effects of environmental and fishing related variables on commercial flatfish species across different regions of the Portuguese coast. For that, sea surface temperature, North Atlantic Oscillation, upwelling index, wind components, river discharges and fishing effort were related to landings per unit effort (LPUE) of five commercial flatfish species (Pleuronectes platessa, Dicologlossa cuneata, Microchirus spp., Solea lascaris, and Solea solea) fished by the artisanal fleet along different regions of Portuguese coast (Northwestern coast, Southwestern coast, and Southern coast), using a multi-model statistical approach from 1989 to 2009. The fishing effort had the same effect along the life cycle and was negatively related with LPUE trends for most of the species. Regarding to environmental variability, during early phases (larval to juvenile – age-group-0) the factors that affected the recruitment, in addition to being related to the physiological needs (e.g., sea surface temperature) of individuals that will trigger growth and survival, were related to larval transport and dispersion from offshore spawning areas to coastal nursery habitats beyond (e.g., wind components and upwelling). For juvenile and young-adult phases (age-groups I and II), the effects of environmental variability appeared to be linked to physiological needs important for growth and maturation (e.g., temperature). Concluding, different effects were observed depending on the region, species, and life-cycle phase. Therefore, these environmental-fishing relationships should be used when managing local fishing resources.

评估捕捞活动与环境变化对捕捞物种的影响，有助于理解其种群波动规律并据此开展科学管理。然而，尽管关联渔业与环境数据的研究数量与日俱增，但鲜有研究采用多物种研究框架，同时涵盖比目鱼物种与不同年龄组群。据此，本研究旨在明确葡萄牙沿岸不同海域中，环境与捕捞相关变量对商业性比目鱼物种的影响。为此，本研究以1989年至2009年葡萄牙沿岸（西北海岸、西南海岸及南部海岸）作业的手工捕捞船队数据为基础，采用多模型统计方法，分析了海表温度、北大西洋涛动（North Atlantic Oscillation）、上升流指数、风场分量、河流径流量及捕捞努力量与5种商业性比目鱼单位捕捞努力量渔获量（LPUE, landings per unit effort）的关联关系，这5种比目鱼分别为欧洲鲽（Pleuronectes platessa）、楔形双线鳎（Dicologlossa cuneata）、小鳎属（Microchirus spp.）、拉氏鳎（Solea lascaris）以及普通鳎（Solea solea）。捕捞努力量在物种整个生活史中表现出一致的影响效应，且与多数物种的LPUE变化趋势呈负相关关系。关于环境变化的影响，在早期生活阶段（幼体至稚鱼期——0龄组），影响种群补充的因素一方面与个体的生理需求（如海表温度）相关，可触发个体生长与存活；另一方面则与幼体从近海产卵场向沿岸育幼栖息地的运移与扩散过程相关（如风场分量与上升流）。而在稚鱼与年轻成体阶段（I龄组与II龄组），环境变化的影响则似乎与个体生长与性成熟所需的生理需求密切相关（如温度）。综上，研究发现不同海域、物种及生活史阶段对应的影响效应存在差异。因此，在开展本地渔业资源管理工作时，应将这些环境-捕捞关联关系纳入参考依据。