Avian predation in catfish aquaculture has been a persistent issue throughout the history of the industry, and as production has expanded predation from piscivorous birds has intensified. Catfish ponds in the Mississippi River delta (in the Mississippi migratory flyway) provide a constant and readily accessible supply of forage for birds. Intensive foraging by fish-eating birds has led to a specific regulatory policy and numerous on-farm and regional management efforts. However, in 2016, legal challenges lead to recision of some federal policies and uncertainty as to allowable management, resulting in limitations on bird depredation. Estimating the extent of fish losses to avian predators is difficult, as loss estimates from farms are often confounded with disease- and management-related mortalities. This study details the reported losses to birds that were observed in commercial-scale catfish ponds at the Thad Cochran National Warmwater Aquaculture Center, Stoneville, Mississippi, during periods of limited bird management. The observed fish losses attributed to birds ranged from 33% to 95% loss in survival and potential yield losses of 4,396 to 8,889 lb/acre, increasing production costs and decreasing net returns. Net economic losses when accounting for negative net returns and lost profits ranged from US$3,518 to $4,060/acre. Losses of this magnitude on commercial fish farms are economically detrimental, especially because catfish farms lack the compensatory economic relief programs that are available in other agriculture sectors. Roost dispersal activities that are organized by federal agencies and avoiding delays in issuing bird depredation permits are vital for mitigating this persistent and growing regulatory problem in the U.S. catfish industry.

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鲶鱼因鸟类捕食而造成的经济损失：案例报告

鲶鱼养殖中的鸟类捕食在整个行业历史中一直是一个持续存在的问题，随着产量的扩大，对食鱼鸟类的捕食也加剧了。密西西比河三角洲（位于密西西比候鸟迁徙路线中）的鲶鱼池塘为鸟类提供了持续且易于获取的饲料供应。以鱼为食的鸟类密集觅食导致了特定的监管政策和大量的农场和区域管理工作。然而，在 2016 年，法律挑战导致一些联邦政策的修订和允许管理的不确定性，导致对鸟类掠夺的限制。估计鸟类捕食者的鱼类损失程度很困难，因为养殖场的损失估计经常与疾病和管理相关的死亡率相混淆。这项研究详细介绍了在鸟类管理有限期间，在密西西比州斯通维尔的 Thad Cochran 国家温水水产养殖中心的商业规模鲶鱼池塘中观察到的鸟类损失报告。观察到的鸟类造成的鱼类损失范围为 33% 至 95% 的生存损失和 4,396 至 8,889 磅/英亩的潜在产量损失，增加了生产成本并降低了净收益。考虑到负净回报和利润损失时，净经济损失从 3,518 美元到 4,060 美元/英亩不等。商业养鱼场如此大规模的损失在经济上是有害的，特别是因为鲶鱼养殖场缺乏其他农业部门可用的补偿性经济救济计划。