Climate change is causing an increase in the frequency and intensity of marine heatwaves (MHWs) and mass mortality events (MMEs) of marine organisms are one of their main ecological impacts. Here, we show that during the 2015–2019 period, the Mediterranean Sea has experienced exceptional thermal conditions resulting in the onset of five consecutive years of widespread MMEs across the basin. These MMEs affected thousands of kilometers of coastline from the surface to 45 m, across a range of marine habitats and taxa (50 taxa across 8 phyla). Significant relationships were found between the incidence of MMEs and the heat exposure associated with MHWs observed both at the surface and across depths. Our findings reveal that the Mediterranean Sea is experiencing an acceleration of the ecological impacts of MHWs which poses an unprecedented threat to its ecosystems' health and functioning. Overall, we show that increasing the resolution of empirical observation is critical to enhancing our ability to more effectively understand and manage the consequences of climate change.

中文翻译：

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海洋热浪导致地中海经常发生大规模死亡

气候变化导致海洋热浪 (MHW) 的频率和强度增加，海洋生物的大规模死亡事件 (MME) 是其主要的生态影响之一。在这里，我们表明，在 2015-2019 年期间，地中海经历了异常的热条件，导致整个盆地连续五年出现广泛的 MME。这些 MME 影响了从地表到 45 m 的数千公里海岸线，跨越一系列海洋生境和分类群（8 个门的 50 个分类群）。在 MME 的发生率和与在地表和跨深度观察到的 MHW 相关的热暴露之间发现了显着的关系。我们的研究结果表明，地中海正在经历 MHW 的生态影响加速，这对其生态系统的健康和功能构成了前所未有的威胁。总体而言，我们表明，提高经验观测的分辨率对于提高我们更有效地理解和管理气候变化后果的能力至关重要。