ABSTRACT: Global warming is increasing the frequency, duration and intensity of extreme events such as marine heat waves (MHWs). The effects of MHWs include a variety of negative environmental impacts. Extreme weather events can interact with other environmental stressors such as invasion by marine non-indigenous species (NIS). The aim of this study was to (1) compare the responses of fouling assemblages recruited within a harbour (highly invaded) with the responses of those recruited in natural habitats (not invaded) to simulated MHWs of different temperatures and durations, and (2) evaluate the legacy effects of those MHWs on the invasibility of both types of assemblage by deploying them in a marina environment (high NIS propagule pressure). Experimental assemblages were sampled after 5 or 10 d of exposure to 1 of 3 different temperature conditions to examine the effects of varying MHW conditions. Later those assemblages were deployed inside a marina facility to test the invasibility of heat-stressed assemblages. The results revealed that higher temperatures and longer MHWs had an overall negative impact on both native and non-indigenous assemblages. Shorter MHWs had greater effects on assemblages dominated by NIS, while longer MHWs affected native species more. Increasing MHW duration promoted increased variability in the resulting invasive assemblages. Winner and loser species and homogenisation could potentially alter the legacy effects of MHWs on the pattern of NIS recruitment. This study highlights the importance of interactions between environmental stressors to the conservation of coastal communities, crucial ecosystems on oceanic islands.

中文翻译：

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赢家和输家：模拟海洋热浪和高繁殖压力下非本土物种的流行

摘要：全球变暖正在增加海洋热浪 (MHW) 等极端事件的频率、持续时间和强度。MHW 的影响包括各种负面的环境影响。极端天气事件可以与其他环境压力因素相互作用，例如海洋非本土物种 (NIS) 的入侵。本研究的目的是 (1) 比较港口内（高度侵入）的污垢组合对不同温度和持续时间的模拟 MHW 的反应与自然栖息地（未侵入）中募集的污垢组合的反应，以及（2）通过在码头环境（高 NIS 繁殖压力）中部署这些 MHW 来评估这些 MHW 对两种类型组合的侵入性的遗留影响。在暴露于 3 种不同温度条件中的一种 5 或 10 天后，对实验组合进行采样，以检查不同 MHW 条件的影响。后来这些组合被部署在一个码头设施内，以测试热应力组合的侵入性。结果表明，更高的温度和更长的 MHW 对本地和非本地组合具有总体负面影响。较短的 MHW 对以 NIS 为主的组合有更大的影响，而较长的 MHW 对本地物种的影响更大。增加 MHW 持续时间促进了由此产生的侵入性组合的可变性增加。赢家和输家物种和同质化可能会改变 MHW 对 NIS 招募模式的遗留影响。