The frequency of abnormally warm water events is increasing not only in surface waters, but also in subsurface layers, with major impacts on benthic ecosystems. Previous insights on heatwave effects have been obtained through field observations or manipulative laboratory experiments. Here, we introduce a system capable of inducing elevated water temperatures in benthic habitats in situ over several days. The system consists of a commercially available electric boiler, usually applied in domestic underfloor heating, and custom-designed benthic acrylic glass chambers connected to individual thermostats. Furthermore, the chambers are semi-open, allowing constant water exchange, maintaining otherwise near-natural conditions, including oxygen concentrations, while the temperature is elevated. The water exchange can be stopped to facilitate incubations measuring changes in benthic fluxes. We conducted a 15-d trial study in July 2021 on a bare-sediment habitat at 2.5 m depth, exposing five chambers to water temperatures 5°C above ambient temperatures for 6 d and comparing with five control chambers. In this assessment, we demonstrate that the temperature control and stability were reliable while maintaining natural oxygen conditions. The modular character of the system permits adaptations for various benthic habitats, facilitating the investigation of elevated temperatures in situ for future climate change scenarios.

中文翻译：

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HOTFLOOR：模拟海底变暖的海底室系统

异常暖水事件的频率不仅在地表水域而且在地下层都在增加，对底栖生态系统产生了重大影响。先前对热浪效应的见解是通过现场观察或实验室操作实验获得的。在这里，我们介绍了一种能够在数天内在原位引起海底栖息地水温升高的系统。该系统由商用电锅炉（通常用于家庭地暖）和连接到单独恒温器的定制设计的底栖丙烯酸玻璃室组成。此外，这些室是半开放的，允许持续的水交换，在温度升高的同时保持接近自然的条件，包括氧气浓度。可以停止水交换以促进孵化，测量底栖通量的变化。我们于 2021 年 7 月在 2.5 m 深的裸露沉积物栖息地进行了为期 15 天的试验研究，将五个室暴露在高于环境温度 5°C 的水温中 6 天，并与五个对照室进行比较。在此评估中，我们证明了在保持自然氧气条件的同时，温度控制和稳定性是可靠的。该系统的模块化特征允许适应各种底栖栖息地，有助于针对未来气候变化情景进行现场高温调查。