Nuñez-Espinosa Valentina, Parada Carolina, Tapia Braulio, Ernst Billy, Porobic Javier, Véliz David, Hinojosa Iván, Yévenes-Vega Leonardo
Programa de Magister en Ciencias mención en oceanografía, Departamento de Oceanografía, Universidad de Concepción, Concepción, Chile.
Departamento de Geofísica, Universidad de Concepción (UdeC), Concepción, Chile.
PLoS One. 2025 Jun 25;20(6):e0325556. doi: 10.1371/journal.pone.0325556. eCollection 2025.
The large increase in the population of long-spined sea urchins (Centrostephanus sylviae) has gained significant attention in the past decade due to the rise in the number of individuals reported as bycatch in Juan Fernandez rock lobster traps (Jasus frontalis) and the risks associated with changes in the ecosystem structure due to the increase in bleaching of reefs in the Juan Fernandez Archipelago (JFA). We explored the demographic surge of the C. sylviae population on Robinson Crusoe and Santa Clara islands (RC-SC) through changes in the relative abundance of adult sea urchins during the years 2015-2022. To seek an explanation for this phenomenon, we explored the potential contributions of early life stages of sea urchins to the adult population via biophysical modeling. We performed simulations of larval dispersal patterns and connectivity between release and recruitment zones for three study years (2013, 2015, and 2018). The results from larval drift simulations combined with observation data from the crustacean fishery monitoring program helped identify recruitment zones (primarily located in the eastern, southeastern, and southwestern areas of RC-SC). Also, we explored the relationship between the relative abundance of adult sea urchins and traits associated with lobsters due to the predator-prey relationship evident in other ecosystems (i.e., in Tasmania and New Zealand). We explored the potential control by lobsters of the sea urchin population size through generalized linear models by analyzing several predictor variables. The results showed that once all zones were combined there was an inverse correlation between the relative abundance of sea urchins and the largest lobsters found in the traps around the islands. This work highlights the complex ecological dynamics resulting from the increase in the C. sylviae population in the JFA system, emphasizing the importance of addressing this issue through ecosystemic and socio-ecologically integrated approaches.
在过去十年中，长棘海胆（Centrostephanus sylviae）数量的大幅增长引起了广泛关注。这是因为据报道，在胡安费尔南德斯岩龙虾（Jasus frontalis）陷阱中的兼捕个体数量有所增加，而且胡安费尔南德斯群岛（JFA）珊瑚礁白化现象增多导致生态系统结构变化带来了相关风险。我们通过2015年至2022年成年海胆相对丰度的变化，探究了鲁滨逊·克鲁索岛和圣克拉拉岛（RC - SC）上长棘海胆种群的数量激增情况。为了解释这一现象，我们通过生物物理模型探究了海胆早期生命阶段对成年种群的潜在贡献。我们对三个研究年份（2013年、2015年和2018年）的幼虫扩散模式以及放流区与补充区之间的连通性进行了模拟。幼虫漂移模拟结果与甲壳类渔业监测计划的观测数据相结合，有助于确定补充区（主要位于RC - SC的东部、东南部和西南部地区）。此外，由于在其他生态系统（即塔斯马尼亚和新西兰）中明显存在捕食者 - 猎物关系，我们还探究了成年海胆相对丰度与龙虾相关特征之间的关系。我们通过分析几个预测变量，利用广义线性模型探究了龙虾对海胆种群数量的潜在控制作用。结果表明，一旦将所有区域合并，海胆的相对丰度与在岛屿周围陷阱中捕获的最大龙虾数量之间存在负相关。这项工作突出了JFA系统中长棘海胆种群增加所导致的复杂生态动态，强调了通过生态系统和社会 - 生态综合方法解决这一问题的重要性。
