Evaluating the benefits and risks of species-transformation provisions in multispecies IFQ fisheries with joint production
Evaluating the benefits and risks of species-transformation provisions in multispecies IFQ fisheries with joint production
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DOI：
10.1093/icesjms/fsw031
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发表时间：
2016-07-01
影响因子：
3.3
通讯作者：
Punt, Andre E.
中科院分区：
文献类型：
--
作者：
Woods, Pamela J.;Holland, Daniel S.;Punt, Andre E.
物种转换条款允许渔民按规定的转换率将一个物种的配额转换为另一个物种的配额。这些规定，连同其他渔获量配额平衡机制，沿着旨在帮助渔民将现有配额与实际渔获量相匹配，以减少弃鱼的动机。在本文中，我们使用一个生物经济模型来研究物种转化条款如何影响多物种渔业的可持续性和盈利能力。我们的参数化模型松散的冰岛底层渔业，目前采用的物种转换的最广泛的实现之一的管理。为了表示渔民每年的行为，将努力量分配给两三个渔场，以使该年的总利润最大化。每一个METIER代表三个物种的可捕率的组合，确定哪些物种是每个METIER的目标，以及一个物种的捕获率与其他物种的捕获率的独立程度。关于渔民在多大程度上可以通过在不同渔场之间转移努力量来瞄准特定鱼种以及不同渔场之间的相对盈利能力如何变化的假设，对于更普遍地理解诸如鱼种转变等捕捞条例如何预期改变捕捞模式至关重要。这一制约因素不仅取决于一个渔场内相关鱼种渔获量的强度，而且取决于相对鱼种丰度和有哪些替代渔场。
Species-transformation provisions allow fishers to convert quota of one species to that of another species at prescribed conversion rates. These provisions, along with other catch-quota balancing mechanisms, are meant to aid fishers in matching available quota to actual catch so that incentives to discard are reduced. In this paper, we use a bioeconomic model to examine how species-transformation provisions affect sustainability and profitability of a multispecies fishery. We base parameterization of the model loosely on management of the Icelandic demersal fishery, which currently employs one of the broadest implementations of species transformations. To represent fisher behaviour in each year, effort is allocated among two or three metiers, such that total profit for that year is maximized. Each metier represents a combination of three species' catchability rates that define which species are targeted by each metier and how independent a species' catch rate is from that of other species. Assumptions regarding the degree to which fishers can target specific species by shifting effort between metiers, as well as how relative profitability among metiers varies, are paramount to understanding more generally how fishing regulations such as species transformations can be expected to change fishing patterns. This constraint depends not only on how strongly associated species catches are within a metier but also on relative species abundance and what alternate metiers are available.