Stage-specific overcompensation, the hydra effect, and the failure to eradicate an invasive predator
Stage-specific overcompensation, the hydra effect, and the failure to eradicate an invasive predator
复制标题
DOI：
10.1073/pnas.2003955118
复制
发表时间：
2021-03-23
影响因子：
11.1
通讯作者：
Tepolt, Carolyn
中科院分区：
文献类型：
--
作者：
Grosholz, Edwin;Ashton, Gail;Tepolt, Carolyn
随着全球生物入侵不断增加，根除计划的成本高昂，而且往往没有考虑相关的生态理论。理论渔业模型表明，捕捞实际上可以增加种群的平衡规模，并且不受控制的研究和轶事报告记录了入侵物种清除导致的种群数量增加（类似于渔业捕捞）。这两项发现可能是由于幼体的高存活率与成体丰度低相关，通常被称为过度补偿。在这里，我们展示了在沿海海洋生态系统中，根除计划导致了特定阶段的过度补偿，并且引入的捕食者的数量在一年内增加了 30 倍。在没有采取根除行动的情况下，从四个邻近区域海湾同时收集的数据显示，没有类似的人口增长，表明是局部而非区域性的增长。具体来说，根除计划无意中减少了对成年人通过同类相食来招募的控制，从而促进了人口爆炸。中宇宙实验证实，成年新兵的同类相食行为与体型有关，并且可以控制新兵的招募。基因组数据显示该种群存在严重隔离，并暗示了种群数量增长的内部动态，而不是从其他地点招募的。更广泛地说，这种水生系统特定阶段过度补偿的受控实验演示为消除连通性有限和相似生活史的物种的努力提供了重要的警示信息。
As biological invasions continue to increase globally, eradication programs have been undertaken at significant cost, often without consideration of relevant ecological theory. Theoretical fisheries models have shown that harvest can actually increase the equilibrium size of a population, and uncontrolled studies and anecdotal reports have documented population increases in response to invasive species removal (akin to fisheries harvest). Both findings may be driven by high levels of juvenile survival associated with low adult abundance, often referred to as overcompensation. Here we show that in a coastal marine ecosystem, an eradication program resulted in stage-specific overcompensation and a 30-fold, single-year increase in the population of an introduced predator. Data collected concurrently from four adjacent regional bays without eradication efforts showed no similar population increase, indicating a local and not a regional increase. Specifically, the eradication program had inadvertently reduced the control of recruitment by adults via cannibalism, thereby facilitating the population explosion. Mesocosm experiments confirmed that adult cannibalism of recruits was size-dependent and could control recruitment. Genomic data show substantial isolation of this population and implicate internal population dynamics for the increase, rather than recruitment from other locations. More broadly, this controlled experimental demonstration of stage-specific overcompensation in an aquatic system provides an important cautionary message for eradication efforts of species with limited connectivity and similar life histories.