Estimating the survivorship of discarded fish is often crucial for stock assessment and resultant management of fisheries resources. In order to assess the survivorship of cuckoo ray () caught in commercial bottom trawl fisheries, experiments involving French and Irish fisheries were conducted. These experiments were particularly challenging considering the fisheries are offshore. Data from these experiments were analysed jointly in this study. Results from monitoring of individuals held in captivity in onshore facilities and observations of vitality status were combined to produce estimates of long-term survival rates across fishing trips in all four seasons. These rates varied greatly between fishing trips and ranged between 3.6% and 26%. Based on indications that the observed mortality may be at least partly attributable to the conditions of captivity, we propose an approach to reduce the underestimation bias when estimating discard survival. This approach produced higher bounds for the estimated discard survival rates. The estimated survival rates are lower than those of other skate species in the North-East Atlantic, suggesting the cuckoo ray is less resilient to trawl-and-release, although previous studies were conducted in shallower water and with shorter haul duration.

中文翻译：

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比斯开湾北部、凯尔特海南部和爱尔兰海底拖网渔业中被遗弃的杜鹃魟的存活率

估计废弃鱼类的存活率对于种群评估和由此产生的渔业资源管理至关重要。为了评估商业底拖网渔业中捕获的布谷鳐鱼的存活率，法国和爱尔兰渔业进行了实验。考虑到渔业位于近海，这些实验尤其具有挑战性。本研究对这些实验的数据进行了联合分析。将陆上设施中圈养个体的监测结果和活力状态观察相结合，得出所有四个季节捕鱼之旅的长期存活率的估计值。这些比率在不同的钓鱼旅行中差异很大，范围在 3.6% 到 26% 之间。有迹象表明观察到的死亡率可能至少部分归因于圈养条件，我们提出了一种在估计丢弃物存活率时减少低估偏差的方法。这种方法为估计的丢弃物存活率产生了更高的界限。估计的存活率低于东北大西洋其他鳐鱼物种的存活率，这表明杜鹃鳐对拖网和释放的抵抗力较差，尽管之前的研究是在较浅的水域进行的，且拖网时间较短。