Adaptive potential of a Pacific salmon challenged by climate change
Adaptive potential of a Pacific salmon challenged by climate change
复制标题
DOI：
10.1038/nclimate2473
复制
发表时间：
2015-02-01
影响因子：
30.7
通讯作者：
Neff, Bryan D.
中科院分区：
文献类型：
--
作者：
Munoz, Nicolas J.;Farrell, Anthony P.;Neff, Bryan D.
太平洋鲑鱼为全世界数百万人提供重要的食物，并对生态系统的生产力产生深远的影响。不断上升的气温现在威胁着这些重要鱼类的生存（1,2），但种群能否适应仍不得而知。在这里，我们提供了第一个证据，表明太平洋鲑鱼具有生理和遗传能力来提高其耐热性以应对不断上升的温度。在幼年奇努克鲑鱼（Oncorhynchus tshawytscha）中，发育温度每升高4摄氏度，心脏功能热性能的关键指标就会升高2摄氏度（3,4）。此外，加性遗传效应显著影响心脏容量的几个指标，表明选择可以对遗传变异起作用。然而，我们发现心脏的温度不规律缺乏可塑性和遗传变异，将这个热上限限制在24.5 +/- 2.2摄氏度。将这种对热耐受性的限制与当前河流温度和预测的变暖情景联系起来(5)，我们预测，根据平均变暖预测，到2100年，人口灾难性损失的可能性为17%，在最大变暖情景中，这一可能性增加到98%。因此，有必要减缓气候变化，以确保太平洋鲑鱼种群未来的生存能力。
Pacific salmon provide critical sustenance for millions of people worldwide and have far-reaching impacts on the productivity of ecosystems. Rising temperatures now threaten the persistence of these important fishes(1,2), yet it remains unknown whether populations can adapt. Here, we provide the first evidence that a Pacific salmon has both physiological and genetic capacities to increase its thermal tolerance in response to rising temperatures. In juvenile chinook salmon (Oncorhynchus tshawytscha), a 4 degrees C increase in developmental temperature was associated with a 2 degrees C increase in key measures of the thermal performance of cardiac function(3,4). Moreover, additive genetic effects significantly influenced several measures of cardiac capacity, indicative of heritable variation on which selection can act. However, a lack of both plasticity and genetic variation was found for the arrhythmic temperature of the heart, constraining this upper thermal limit to a maximum of 24.5 +/- 2.2 degrees C. Linking this constraint on thermal tolerance with present-day river temperatures and projected warming scenarios(5), we predict a 17% chance of catastrophic loss in the population by 2100 based on the average warming projection, with this chance increasing to 98% in the maximum warming scenario. Climate change mitigation is thus necessary to ensure the future viability of Pacific salmon populations.