Abstract Significant increases in the population of the echinoid bioeroder Diadema mexicanum that may soon follow severe El Nino events, such as in 1982–1983, can have a significant negative impact on the carbonate budget of coral reefs. We developed a spatially explicit model that uses agent-based modeling techniques to simulate the interactions between damselfish and sea urchins on an eastern Pacific coral reef following an El Nino-Southern Oscillation (ENSO) event where high echinoid abundances and low coral cover were prevalent. Our modeling study suggests that the agonistic behavior of damselfish towards echinoids invading their defended algal lawn territories has a magnifying effect on the degree of bioerosion attributed to echinoids. This is due to the increased likelihood that sea urchins ejected from damselfish territories will form concentrated aggregations and remain grazing and eroding coral for longer periods of time. This is a novel insight that contrasts with the previous understanding of the positive effect that damselfish have on reef carbonate budgets by protecting carbonate substrates that lie within their defended algal lawn territories. The increased degradation of coral stands attributed to the indirect damselfish effect, if it results in sea urchins eroding subsurface coral framework structures, causing instability and collapse (especially during periods of high-water motion), may contribute to the fracturing of large portions of coral framework blocks, affecting the recovery trajectory of reefs following a severe El Nino disturbance event.

中文翻译：

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基于代理的东太平洋雀鲷和海胆相互作用模型显示在后 ENSO 条件下珊瑚礁侵蚀增加

摘要 在严重的厄尔尼诺事件（例如 1982-1983 年）之后，海胆生物侵蚀者 Diadema mexicanum 的数量可能会显着增加，这会对珊瑚礁的碳酸盐预算产生重大的负面影响。我们开发了一个空间显式模型，该模型使用基于代理的建模技​​术来模拟在厄尔尼诺 - 南方涛动 (ENSO) 事件发生后东太平洋珊瑚礁上雀鲷和海胆之间的相互作用，其中海胆类丰度高且珊瑚覆盖率低。我们的模型研究表明，雀鲷对入侵其防御藻类草坪领地的海胆类动物的激动行为对海胆类动物的生物侵蚀程度具有放大作用。这是因为从雀鲷的领地中排出的海胆更有可能形成集中的聚集体，并在更长的时间内继续吃草和侵蚀珊瑚。这是一个新颖的见解，与之前对雀鲷通过保护位于其防御藻类草坪领土内的碳酸盐基质对珊瑚礁碳酸盐预算的积极影响的理解形成对比。珊瑚群退化加剧归因于间接雀鲷效应，如果它导致海胆侵蚀地下珊瑚框架结构，导致不稳定和坍塌（特别是在高水位运动期间），则可能导致大部分珊瑚破裂框架块，影响严重厄尔尼诺干扰事件后珊瑚礁的恢复轨迹。