Stable landings mask irreversible community reorganizations in an overexploited Mediterranean ecosystem

1. Background. Cumulative human pressures can induce non-linear discontinuous dynamics in ecosystems, known as regime shifts. Regime shifts typically imply hysteresis, a lacking or delayed system response when pressures are reverted, which can frustrate restoration efforts. 2. The goal of the study. Here we investigate whether the northern Adriatic Sea fish and macroinvertebrate community, depicted by commercial fishery landings, has undergone irreversible regime shifts over the last 40 years. 3. What was done. We use a stochastic cusp model to show that, under the interactive effect of fishing and warming, the community reorganized through discontinuous changes. 4. What was found. Part of the community has now reached a new stable state, implying that a recovery towards previous baselines might be impossible. Interestingly, total landings remained constant across decades, masking the low resilience of the community. 5. The relevance. Our study reveals the importance of carefully assessing regime shifts and resilience in marine ecosystems and advocates for their inclusion into management.1. 背景。累积的人类活动压力可引发生态系统出现非线性不连续动态变化，这类变化被定义为状态转换（regime shifts）。状态转换通常伴随滞后效应（hysteresis），即当人为压力解除后，系统响应出现滞后或缺失，这会阻碍生态修复工作的推进。 2. 研究目标。本研究旨在探究：以商业渔业捕捞量为表征的亚得里亚海北部鱼类与大型无脊椎动物群落，在过去40年间是否发生了不可逆的状态转换（regime shifts）。 3. 研究方法与结果。本研究采用随机尖点模型（stochastic cusp model）开展分析，结果表明：在捕捞与海洋变暖的协同作用下，该群落通过不连续动态变化完成了重组。 4. 核心发现。目前该群落的部分类群已进入新的稳定状态，这意味着恢复至原有基准状态或将不再可能。值得注意的是，数十年间总捕捞量始终保持稳定，这一现象掩盖了该群落低下的恢复力（resilience）。 5. 研究意义。本研究揭示了在海洋生态系统中审慎评估状态转换与恢复力的重要性，并呼吁将二者纳入海洋生态管理体系之中。