ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia.
Australian Institute of Marine Science, Townsville, Queensland, Australia.
Glob Chang Biol. 2024 Oct;30(10):e17506. doi: 10.1111/gcb.17506.
Anthropogenic pressure is increasing the variety and frequency of environmental disturbance events, limiting recovery and leading to long-term declines in wild plant and animal populations. Coral reefs and associated fish assemblages are inherently dynamic due to their susceptibility to a host of disturbances, but regional-scale nuances in the drivers of long-term change frequently remain poorly resolved. Here, we examine the effects of multiple potential drivers of change in coral reef fish assemblages across 4 inshore regions of the Great Barrier Reef Marine Park (GBRMP), Australia, over 12-14 years (2007-2021). Each region had a unique disturbance history, in conjunction with long-term changes in physical and habitat variables. Phases of recovery were apparent in the years between disturbance events at all locations, but these were not long enough to prevent substantial declines in reef fish density (by 33%-72%) and species richness (by 41%-75%) throughout the study period. The main drivers of change in fish assemblages varied among regions; however, the most rapid changes followed cyclone and flood events. Limited recovery periods resulted in temporal shifts in fish species composition from typically coral-associated to algae-associated. Most trophic groups declined in density except farmers, grazers, omnivores and parrotfish. No-take marine reserves (NTMRs) had small and inconsistent effects on total fish assemblages, but delivered benefits for fishery-targeted piscivores. Our findings suggest that coral reef responses to local stressors and cumulative escalating climate change impacts are highly variable at regional scales, and that small NTMRs are unlikely to mitigate the impacts of increasingly frequent climatic disturbances. Nearshore coral reefs worldwide are high-value habitats that are either already degraded or vulnerable to degradation and the loss of important fish groups. Global efforts to reduce greenhouse gas emissions must be coupled with effective local management that can support the functioning and adaptive capacity of coral reefs.
人为压力正在增加环境干扰事件的种类和频率，限制了恢复速度，并导致野生植物和动物种群长期减少。珊瑚礁及其相关鱼类组合由于容易受到多种干扰而具有内在的动态性，但区域尺度上长期变化的驱动因素常常仍未得到很好的解决。在这里，我们研究了澳大利亚大堡礁海洋公园（GBRMP）4 个近岸地区的多个潜在变化驱动因素对珊瑚礁鱼类组合的影响，时间跨度为 12-14 年（2007-2021 年）。每个地区都有独特的干扰历史，加上物理和栖息地变量的长期变化。在所有地点，干扰事件之间的恢复阶段都很明显，但这些阶段不足以防止整个研究期间珊瑚鱼密度（下降 33%-72%）和物种丰富度（下降 41%-75%）的大量减少。鱼类组合变化的主要驱动因素因地区而异；然而，最快速的变化紧随气旋和洪水事件而来。有限的恢复期导致鱼类物种组成从典型的珊瑚相关转变为藻类相关。除了渔民、食草动物、杂食动物和鹦鹉鱼外，大多数营养群体的密度都有所下降。禁捕海洋保护区（NTMRs）对鱼类总组合的影响较小且不一致，但对渔业目标的肉食性鱼类有好处。我们的研究结果表明，珊瑚礁对局部压力源和累积的气候变暖影响的反应在区域尺度上具有高度的可变性，而且小型 NTMR 不太可能减轻日益频繁的气候干扰的影响。全球近岸珊瑚礁是高价值的栖息地，要么已经退化，要么容易退化，失去重要的鱼类群体。减少温室气体排放的全球努力必须与有效的地方管理相结合，以支持珊瑚礁的功能和适应能力。
