Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Biologische Anstalt Helgoland, Helgoland, Germany.
University of Bremen, Bremen, Germany.
J Anim Ecol. 2024 Oct;93(10):1524-1540. doi: 10.1111/1365-2656.14165. Epub 2024 Aug 23.
Marine heatwaves (MHWs) are extreme weather events that have major impacts on the structure and functioning of marine ecosystems worldwide. Due to anthropogenic climate change, the occurrence of MHWs is predicted to increase in future. There is already evidence linking MHWs with reductions in biodiversity and incidence of mass mortality events in coastal ecosystems. However, because MHWs are unpredictable, the quantification of their effects on communities is challenging. Here, we use the Helgoland Roads long-term time series (German Bight, North Sea), one of the richest marine time series in the world, and implement a modified before-after control-impact (BACI) design to evaluate MHW effect on mesozooplankton communities. Mesozooplankton play an essential role in connecting primary producers to higher trophic levels, and any changes in their community structure could have far-reaching impacts on the entire ecosystem. The responses of mesozooplankton community to MHWs in terms of community structure and densities occurred mainly in spring and autumn. Abundances of seven taxa, including some of the most abundant groups (e.g. copepods), were affected either positively or negatively in response to MHWs. In contrast, we observed no clear evidence of an impact of summer and winter MHWs; instead, the density of the most common taxa remained unchanged. Our results highlight the seasonally dependent impacts of MHWs on mesozooplankton communities and the challenges in evaluating those impacts. Long-term monitoring is an important contributor to the quantification of effects of MHWs on natural populations.
海洋热浪（MHWs）是极端天气事件，对全球海洋生态系统的结构和功能有重大影响。由于人为气候变化，预计未来 MHWs 的发生频率将会增加。已经有证据表明，MHWs 与沿海生态系统生物多样性减少和大规模死亡事件的发生有关。然而，由于 MHWs 是不可预测的，因此量化它们对群落的影响具有挑战性。在这里，我们使用 Helgoland Roads 长期时间序列（德国北海），这是世界上最丰富的海洋时间序列之一，并实施了改进的前后对照影响（BACI）设计，以评估 MHW 对中型浮游动物群落的影响。中型浮游动物在将初级生产者与更高营养级联系起来方面发挥着重要作用，其群落结构的任何变化都可能对整个生态系统产生深远影响。中型浮游动物群落对 MHWs 的反应在群落结构和密度方面主要发生在春季和秋季。七个类群的丰度受到 MHWs 的影响，包括一些最丰富的群体（例如桡足类），无论是正面还是负面。相比之下，我们没有观察到夏季和冬季 MHWs 明显影响的证据；相反，最常见类群的密度保持不变。我们的研究结果突出了 MHWs 对中型浮游动物群落的季节性影响以及评估这些影响的挑战。长期监测是量化 MHWs 对自然种群影响的重要贡献。
