Seawater carbonate chemistry and energy metabolism and survival of the juvenile recruits of the American lobster (Homarus americanus)

The transition from the last pelagic larval stage to the first benthic juvenile stage in the complex life cycle of marine invertebrates, such as the American lobster Homarus americanus, a species of high economic importance, represents a delicate phase in these species development. Under future elevated pCO2 conditions, ocean acidification and other elevated pCO2 events can negatively affect crustaceans. This said their effects on the benthic settlement phase are virtually unknown. This study aimed to identify the effects of elevated seawater pCO2 on stage V American lobsters exposed to seven pCO2 levels. The survival, development time, metabolic and feeding rates, carapace composition, and mitochondrial function were investigated. Results suggested an increase in mortality, slower development and a reduction in aerobic capacity with increasing pCO2. Our study points to potential reduction in juvenile recruitment success as seawater pCO2 increases, thus foreshadowing important socio-economic repercussions for the lobster fisheries and industry.

海洋无脊椎动物复杂生命周期中，从终末浮游幼体阶段向首代底栖稚体阶段的转变，是该类群发育过程中的关键脆弱阶段——以具有极高经济价值的美洲螯龙虾（Homarus americanus）为例。在未来二氧化碳分压（pCO₂）升高的情景下，海洋酸化及其他CO₂分压升高事件会对甲壳类动物产生负面影响，但此类因素对底栖附着阶段的影响目前仍几乎未被探明。本研究以7个不同CO₂分压梯度下暴露的第V期美洲螯龙虾为研究对象，旨在探明海水CO₂分压升高对其产生的影响，研究人员对受试个体的存活率、发育时长、代谢与摄食速率、甲壳组成以及线粒体功能开展了检测分析。结果显示，随着CO₂分压升高，个体死亡率上升、发育速率放缓，有氧代谢能力亦出现下降。本研究表明，随着海水CO₂分压升高，稚体补充成功率或出现下降，这将为螯龙虾渔业及相关产业带来潜在的重大社会经济影响。