Helmholtz Centre for Ocean Research Kiel (GEOMAR), 24105 Kiel, Germany.
Integrative Ecophysiology, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, 27570 Bremerhaven, Germany.
Sci Adv. 2017 Apr 26;3(4):e1602411. doi: 10.1126/sciadv.1602411. eCollection 2017 Apr.
Ocean acidification severely affects bivalves, especially their larval stages. Consequently, the fate of this ecologically and economically important group depends on the capacity and rate of evolutionary adaptation to altered ocean carbonate chemistry. We document successful settlement of wild mussel larvae () in a periodically CO-enriched habitat. The larval fitness of the population originating from the CO-enriched habitat was compared to the response of a population from a nonenriched habitat in a common garden experiment. The high CO-adapted population showed higher fitness under elevated co (partial pressure of CO) than the non-adapted cohort, demonstrating, for the first time, an evolutionary response of a natural mussel population to ocean acidification. To assess the rate of adaptation, we performed a selection experiment over three generations. CO tolerance differed substantially between the families within the F generation, and survival was drastically decreased in the highest, yet realistic, co treatment. Selection of CO-tolerant F animals resulted in higher calcification performance of F larvae during early shell formation but did not improve overall survival. Our results thus reveal significant short-term selective responses of traits directly affected by ocean acidification and long-term adaptation potential in a key bivalve species. Because immediate response to selection did not directly translate into increased fitness, multigenerational studies need to take into consideration the multivariate nature of selection acting in natural habitats. Combinations of short-term selection with long-term adaptation in populations from CO-enriched versus nonenriched natural habitats represent promising approaches for estimating adaptive potential of organisms facing global change.
海洋酸化严重影响双壳类动物，尤其是它们的幼虫阶段。因此，这个生态和经济上都很重要的群体的命运取决于其适应变化的海洋碳酸盐化学的能力和速度。我们记录了野生贻贝幼虫（）在周期性富 CO 环境中的成功定居。在一个共同花园实验中，比较了来自 CO 富集生境的种群的幼虫适应性与来自非富集生境的种群的响应。与未适应的群体相比，高 CO 适应群体在高 CO（CO 分压）下表现出更高的适应性，这首次证明了自然贻贝种群对海洋酸化的进化响应。为了评估适应速度，我们进行了三代选择实验。在 F 代的各个家庭之间，CO 耐受性有很大差异，在最高但仍现实的 CO 处理中，存活率急剧下降。CO 耐受型 F 动物的选择导致 F 幼虫在早期壳形成过程中的钙化性能提高，但并未提高总体存活率。因此，我们的研究结果揭示了在关键双壳类物种中，受海洋酸化直接影响的性状具有显著的短期选择响应，并且具有长期适应潜力。由于对选择的直接响应并未直接转化为适应性增加，因此在自然栖息地中进行的多代研究需要考虑到选择作用的多变量性质。来自富 CO 和非富 CO 自然栖息地的种群的短期选择与长期适应的组合代表了估计面临全球变化的生物体适应潜力的有前途的方法。
