Matching catches to quotas in a multispecies trawl fishery: targeting and avoidance behavior under individual transferable quotas
Matching catches to quotas in a multispecies trawl fishery: targeting and avoidance behavior under individual transferable quotas
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DOI：
10.1139/f08-065
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发表时间：
2008-07-01
影响因子：
2.4
通讯作者：
Hilborn, Ray
中科院分区：
文献类型：
--
作者：
Branch, Trevor A.;Hilborn, Ray
只有当渔民对其捕获物中的物种混合有高度控制时，优化多物种渔业的产量才有可能，尽管鼓励这种行为的激励措施很少到位。一个例外是加拿大不列颠哥伦比亚省的底栖鱼拖网渔业，其中22个鱼种的总可捕量由个别可转让配额管理，观察员覆盖率为100%，并从配额中扣除丢弃死亡率。尽管所涵盖的鱼种数目很多，但当某些鱼种的总可捕量增加而另一些鱼种的总可捕量减少时，渔民能够调整其渔获量中的鱼种混合。排名前34位的渔船经常光顾的“捕鱼机会”范围很广（平均38次，范围20-69次）（沿着同一航线重复拖网），其中含有可预测的物种混合物。当粗眼鱼（Arougheye aleutianus）、短尾鱼（Aroughetes borealis）和黄眼岩鱼（Aroughetes ruberrimus）的总可捕量急剧减少时，渔民避免在这些物种更丰富的地方捕鱼。更一般地说，它们对捕捞机会的选择取决于预期的多鱼种组成，尽管其他因素可能也很重要。
Optimizing yield in multispecies fisheries is only possible when fishers have a high degree of control over the species mixture in their catches, although incentives to encourage this kind of behavior are rarely in place. One exception is the British Columbia, Canada, groundfish trawl fishery, where individual transferable quotas govern total allowable catches (TACs) for 22 species, combined with 100% observer coverage and the deduction of discard mortality from quota. Despite the number of species covered, when TACs were increased for some species and reduced for others, fishers were able to adjust the species mixture in their catches. The top 34 vessels frequented a wide range (mean 38, range 20-69) of "fishing opportunities" (repeated trawls along the same track line) containing predictable species mixtures. When TACs for rougheye (Sebastes aleutianus), shortraker (Sebastes borealis), and yelloweye rockfish (Sebastes ruberrimus) were sharply cut, fishers avoided fishing opportunities where these species were more abundant. More generally, their choice of fishing opportunities depended on the expected multispecies composition, although other factors were probably also important.