Abstract The unintentional capture (bycatch) of seabirds in gillnet fisheries kills hundreds of thousands of individuals annually and is thought to threaten the conservation of entire populations. However, data from commercial fisheries is often lacking to confirm these suspicions. In Denmark, sparse or incomplete catch data from small-scale gillnetters prevent managers from gaining a comprehensive overview of the importance of seabird bycatch in coastal waters. In this study, electronic monitoring (EM) with video is used to identify and quantify seabird bycatch in a Danish coastal gillnet fishery. Three gillnetters were monitored over a period of 9 years, resulting in 2118 fishing trips and 10,964 hauls; 700 birds from six families were identified. Three species composed >90% of the incidental captures, the common eider (Somateria mollissima), the great cormorant (Phalacrocorax carbo) and the common guillemot (Uria aalge), respectively qualifying regionally as endangered, least concerned and near threatened. There was a clear species-specific spatial and seasonal variability in bycatch per unit effort (BPUE) estimates, highlighting areas of high risk of seabird bycatch. Approximately 40% of all bycatch events were observed in 0.2% of the hauls, suggesting that the full fishing activity should be analysed to obtain accurate seabird bycatch estimates.

中文翻译：

---

使用电子监测评估刺网渔业中的海鸟兼捕

摘要 刺网渔业中无意捕获（兼捕）海鸟每年导致数十万人死亡，并被认为威胁到整个种群的保护。然而，商业渔业的数据往往无法证实这些怀疑。在丹麦，小规模刺网者的捕捞数据稀少或不完整，使管理人员无法全面了解沿海水域海鸟兼捕的重要性。在这项研究中，使用带视频的电子监控 (EM) 来识别和量化丹麦沿海刺网渔业中的海鸟兼捕。在 9 年的时间里对三只刺网鱼进行了监测，共进行了 2118 次捕鱼和 10,964 次捕捞；鉴定了来自六个科的 700 只鸟。三个物种组成> 90％的偶然捕获，普通绒毛（Somateria mollissima），鸬鹚 (Phalacrocorax carbo) 和海鸬鹚 (Uria aalge) 分别在区域内被列为濒危、最不受关注和近危的物种。单位努力兼捕 (BPUE) 估计值存在明显的特定物种空间和季节性变化，突出了海鸟兼捕的高风险区域。在 0.2% 的捕捞量中观察到大约 40% 的所有兼捕事件，这表明应分析完整的捕捞活动以获得准确的海鸟兼捕估计数。