Global catches, exploitation rates, and rebuilding options for sharks
Global catches, exploitation rates, and rebuilding options for sharks
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DOI：
10.1016/j.marpol.2012.12.034
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发表时间：
2013-07-01
期刊：
影响因子：
3.8
通讯作者：
Gruber, Samuel H.
中科院分区：
文献类型：
--
作者：
Worm, Boris;Davis, Brendal;Gruber, Samuel H.
充分养护和管理鲨鱼种群在全球范围内变得越来越重要，特别是因为许多物种特别容易受到过度捕捞的影响。然而，报告的鲨鱼渔获量统计数字并不完整，也没有鲨鱼作为一个群体的死亡率估计数。据估计，2000年全球鲨鱼捕获量和因报告和未报告的上岸、丢弃和割取鲨鱼鳍而死亡的鲨鱼数量为144万公吨，2010年仅略少（141万吨）。根据对鲨鱼平均重量的分析，这意味着2000年鲨鱼的年死亡总数估计约为1亿条，2010年约为9 700万条，每年可能死亡的鲨鱼总数在6 300万至2.73亿条之间。此外，鲨鱼作为一个群体的开发率是用两个独立的死亡率估计数除以全球总生物量估计数计算出来的。作为一种替代办法，根据种群评估和其他公布的资料来源，汇编并平均了个别鲨鱼种群的开发率。由此产生的三个独立估计的平均开发率范围在6.4%和7.9%之间的鲨鱼每年被杀害。这超过了许多鲨鱼种群的平均反弹率，根据62种鲨鱼物种的生活史信息估计（反弹率平均每年4.9%），并解释了大多数有数据的种群持续下降的原因。这些不可持续的渔获量和死亡率对海洋生态系统的影响可能是巨大的。因此，需要大幅度降低全球鲨鱼总死亡率，以重建枯竭的种群，恢复具有功能性顶级捕食者的海洋生态系统。(C)2013年爱思唯尔有限公司保留所有战斗。
Adequate conservation and management of shark populations is becoming increasingly important on a global scale, especially because many species are exceptionally vulnerable to overfishing. Yet, reported catch statistics for sharks are incomplete, and mortality estimates have not been available for sharks as a group. Here, the global catch and mortality of sharks from reported and unreported landings, discards, and shark finning are being estimated at 1.44 million metric tons for the year 2000, and at only slightly less in 2010 (1.41 million tons). Based on an analysis of average shark weights, this translates into a total annual mortality estimate of about 100 million sharks in 2000, and about 97 million sharks in 2010, with a total range of possible values between 63 and 273 million sharks per year. Further, the exploitation rate for sharks as a group was calculated by dividing two independent mortality estimates by an estimate of total global biomass. As an alternative approach, exploitation rates for individual shark populations were compiled and averaged from stock assessments and other published sources. The resulting three independent estimates of the average exploitation rate ranged between 6.4% and 7.9% of sharks killed per year. This exceeds the average rebound rate for many shark populations, estimated from the life history information on 62 shark species (rebound rates averaged 4.9% per year), and explains the ongoing declines in most populations for which data exist. The consequences of these unsustainable catch and mortality rates for marine ecosystems could be substantial. Global total shark mortality, therefore, needs to be reduced drastically in order to rebuild depleted populations and restore marine ecosystems with functional top predators. (C) 2013 Elsevier Ltd. All fights reserved.