Derville et al. 2023 model data: whale abundance, fishing effort, and exposure by fishing zones

Dataset used in models for Derville et al. 2023 Biological Conservation, "Exposure of whales to entanglement risk in Dungeness crab fish-ing gear in Oregon, USA, reveals distinctive spatio-temporal and climatic patterns" Abstract: Entanglement in fishing gear presents a major threat to marine mammals worldwide and a pressing concern for distinct populations of whales off the US West Coast. The lack of understanding of their fine-scale distribution in relation to fishing activity limits management efforts, specifically in Oregon. Based on year-round predictions of rorqual whale densities and fishing effort compiled from logbooks, we assess co-occurrence between commercial Dungeness crab fishing gear and whales over a decade (2011-2020) as an indicator of exposure to entanglement risk. Generalized Additive Models including temporal, climatic, and ocean upwelling predictors were used to investigate variations in exposure. Exposure peaked in April, at the onset of the upwelling season when whales were predicted to occur in greater numbers and closer to shore. Exposure remained constant until the end of the crab season in nearshore waters <40 fathoms (73 m) and decreased past these depths. Across years, exposure was lower during the marine heatwave (2014-2016) when fishing was more active nearshore and whales were predicted to be less abundant. Exposure was higher before (2011-2013) and after (2017-2020) the heatwave, which correspond to negative phases of the Pacific Decadal Oscillation associated with stronger upwelling, indicating more productive conditions favorable to whales. A recent increase in exposure was also due to a slight shift in fishing effort towards deeper waters. These findings illustrate the use of fine-scale species distribution models to assess space-use conflicts in dynamic marine ecosystems and can be used to guide fisheries management to reduce entanglement risk in Oregon.

本数据集用于Derville等人2023年发表于学术期刊《Biological Conservation》的研究论文《美国俄勒冈州邓杰内斯蟹捕捞渔具中鲸鱼缠绊风险暴露情况揭示独特的时空与气候模式》。
论文摘要：渔业渔具缠绊是全球海洋哺乳动物面临的重大威胁，也是美国西海岸近海特有鲸类种群亟需应对的紧迫问题。此前由于缺乏对鲸类与捕捞活动相关的精细尺度分布的认知，俄勒冈州的相关管理工作推进受限。本研究基于全年须鲸（rorqual）密度预测结果，以及从捕捞日志汇编得到的捕捞努力量数据，评估了2011-2020年十年间商业邓杰内斯蟹捕捞渔具与鲸类的空间重叠情况，以此作为鲸类暴露于缠绊风险的指标。研究采用包含时间、气候与海洋上升流预测因子的广义可加模型（Generalized Additive Models），探究了风险暴露水平的变化规律。
风险暴露峰值出现在4月，即上升流季伊始，此时预测的鲸类种群数量更多且更贴近近岸海域。在水深小于40英寻（73米）的近岸水域，暴露水平维持稳定直至蟹类捕捞季结束，而在更深海域，暴露水平则随水深增加而下降。
跨年度分析显示，2014-2016年海洋热浪（marine heatwave）期间，尽管近岸捕捞活动更为频繁，但预测的鲸类种群丰度更低，因此风险暴露水平整体偏低。而在海洋热浪发生前（2011-2013年）与发生后（2017-2020年），风险暴露水平更高，这两个时期对应太平洋年代际振荡（Pacific Decadal Oscillation）的负相位，彼时上升流更强、海洋生产力更高，更利于鲸类生存。近期风险暴露水平上升还与捕捞努力量向更深海域的小幅转移有关。
本研究结果证明了精细尺度物种分布模型可用于评估动态海洋生态系统中的空间利用冲突，相关成果可用于指导俄勒冈州的渔业管理工作，以降低鲸类缠绊风险。