Evolutionary regime shifts in age and size at maturation of exploited fish stocks
Evolutionary regime shifts in age and size at maturation of exploited fish stocks
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DOI：
10.1098/rspb.2006.3518
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发表时间：
2006-08-07
影响因子：
4.7
通讯作者：
Persson, Lennart
中科院分区：
文献类型：
--
作者：
de Roos, Andre M.;Boukal, David S.;Persson, Lennart
世界范围内鱼类种群的减少引起了人们对捕捞对种群丰度和个体生活史的有害后果的关注，并呼吁采取适当的恢复战略。由于遗传和可塑性反应，被开发种群中的鱼要么更大，要么更小，成熟得更早。当减少对食物的竞争导致更快的增长时，后者通常会发生。使用一个同时考虑遗传和塑料反应的大小结构消费者资源模型，我们表明，渔业引发的个体生活史和种群属性的进化变化很容易变得不可逆转。作为一年产卵的结果，在其他相同的环境条件下，小个体的早熟和大个体的晚熟可以成为进化和生态稳定的替代状态。对晚熟种群的开发可以诱导进化机制向较小的成熟规模转变，这与第一次繁殖时年龄逐步下降1岁有关。完全和早期休渔会慢慢逆转这一进程，但迟来的或部分休渔可能会加速或甚至煽动在成熟时进一步进化到较小的规格。我们认为，成熟年龄的逐步下降可以作为即将到来的进化变化的早期警告，并应激励及时限制渔业。
Worldwide declines of fish stocks raise concerns about deleterious consequences of harvesting for stock abundances and individual life histories, and call for appropriate recovery strategies. Fishes in exploited stocks mature earlier at either larger or smaller sizes due to both genetic and plastic responses. The latter occur commonly when reduced competition for food leads to faster growth. Using a size-structured consumer-resource model, which accounts for both genetic and plastic responses, we show that fisheries-induced evolutionary changes in individual life history and stock properties can easily become irreversible. As a result of annual spawning, early maturation at small sizes and late maturation at large sizes can become alternative, evolutionarily and ecologically stable states under otherwise identical environmental conditions. Exploitation of late-maturing populations can then induce an evolutionary regime shift to smaller maturation sizes associated with stepwise, 1-year decreases in age at first reproduction. Complete and early fishing moratoria slowly reverse this process, but belated or partial closure of fisheries may accelerate or even instigate further evolution to smaller sizes at maturation. We suggest that stepwise decreases in maturation age can be used as early warnings of upcoming evolutionary changes, and should inspire timely restrictions of fisheries.