Survivors of Climate Driven Abalone Mass Mortality Exhibit Declines in Health and Reproduction Following Kelp Forest Collapse
Survivors of Climate Driven Abalone Mass Mortality Exhibit Declines in Health and Reproduction Following Kelp Forest Collapse
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DOI：
10.3389/fmars.2021.725134
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发表时间：
2021-08-16
影响因子：
3.7
通讯作者：
Catton, Cynthia A.
中科院分区：
文献类型：
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作者：
Rogers-Bennett, Laura;Klamt, Robert;Catton, Cynthia A.
海洋生态系统很容易受到海洋热浪等气候驱动事件的影响，但我们对它们是否会崩溃或恢复的了解甚少。海带森林是众所周知的易感，并已在世界各地的海胆荒地上升。当温度升高时，生理需求也会增加，而食物资源会减少，从而收紧代谢限制。在这个案例研究中，我们研究红鲍（Haliotis rufescens）的亚致命的影响，并在海藻森林已转移到海胆贫瘠的恢复前景。鲍鱼是一种休闲捕捞物种，曾经在北方加州的公牛海带森林中蓬勃发展，但自2014-2016年海洋热浪以来，最近遭受了大规模死亡。在崩溃之前和之后，都有关于鲍鱼健康和繁殖的定量数据。大规模死亡的幸存者在身体和性腺状况指数方面表现出2年的滞后。滞后后，身体和性腺指数大幅下降，壳长和体重之间的关系。每只雌性的成熟卵产量下降了99%（p < 0.001），每克雌性体重的卵数（2，984/g）下降到接近零（9/g）。有精子的男性数量减少了33%，精子丰度评分减少了28%（p = 0.414）。我们观察到这些减少是针对成熟的卵子和精子，而未成熟的卵子和精子细胞仍然大量存在。在实验室中，在重新引入海带后，体重增加在第二次饥饿期后迅速消失。这个例子说明了气候驱动的基础物种减少如何通过影响身体状况和幸存个体的未来繁殖来抑制系统的恢复。鉴于北方加州的剩余鲍鱼的繁殖潜力差，再加上持续的死亡率和低海带丰度，我们讨论了需要保持休渔期，并实施积极的鲍鱼恢复措施。对于捕捞物种，如鲍鱼，气候变化对恢复造成的额外障碍对于理解和纳入资源管理和恢复至关重要。
Marine ecosystems are vulnerable to climate driven events such as marine heatwaves yet we have a poor understanding of whether they will collapse or recover. Kelp forests are known to be susceptible, and there has been a rise in sea urchin barrens around the world. When temperatures increase so do physiological demands while food resources decline, tightening metabolic constraints. In this case study, we examine red abalone (Haliotis rufescens) looking at sublethal impacts and their prospects for recovery within kelp forests that have shifted to sea urchin barrens. Abalone are a recreationally fished species that once thrived in northern California's bull kelp forests but have recently suffered mass mortalities since the 2014-2016 marine heatwave. Quantitative data exist on the health and reproduction of abalone both prior to and after the collapse. The survivors of the mass mortality show a 2-year lag in body and gonad condition indices. After the lag, body and gonad indexes decreased substantially, as did the relationship between shell length and body weight. Production of mature eggs per female declined by 99% (p < 0.001), and the number of eggs per gram of female body weight (2,984/g) declined to near zero (9/g). The number of males with sperm was reduced by 33%, and the sperm abundance score was reduced by 28% (p = 0.414). We observed that these reductions were for mature eggs and sperm while immature eggs and spermatids were still present in large numbers. In the lab, after reintroduction of kelp, weight gains were quickly lost following a second starvation period. This example illustrates how climate-driven declines in foundation species can suppress recovery of the system by impacting body condition and future reproduction of surviving individuals. Given the poor reproductive potential of the remaining abalone in northern California, coupled with ongoing mortality and low kelp abundances, we discuss the need to maintain the fishing moratorium and implement active abalone restoration measures. For fished species, such as abalone, this additional hurdle to recovery imposed by changes in climate is critical to understand and incorporate into resource management and restoration.