Aquarium monitoring during a land-based experiment testing the cumulative effect of Cu exposure and ocean acidification on cold-water coral Dentomuricea aff. meteor

We report the results of a land-based experiment testing the cumulative effects of copper (Cu) exposure and ocean acidification (OA). Corals were obtained as by-catch during experimental long-line fisheries campaigns on board R/V "Arquipélago" (ARQDAÇO monitoring program, University of the Azores) at Baixa de São Mateus at 185 m depth in April 2019. The experiment was undertaken at the DeepSeaLab aquaria facilities (Okeanos-University of the Azores) where corals were exposed to four OA/Cu-contamination scenarios: (1) ambient pCO2/pH level as measured in situ conditions (385 μatm/ pH 8.09); (2) high pCO2/reduced pH (IPCC RCP8.5 scenario, 1000 μatm/ pH 7.73); (3) ambient pCO2/pH level and additional Cu concentration (60 µg/l); (4) high pCO2/reduced pH and additional Cu concentration (60 µg/l). The pH/pCO2 modification was achieved by bubbling seawater with either pure CO2 (to increase pCO2) or CO2 low air (to decrease pCO2). The copper concentration used in this experiment followed a trial simulating a polymetallic particles plume release during a potential deep-sea mining event. This sublethal concentration was found to be the highest copper concentration dissolved in seawater.Seawater physical-chemical parameters were measured daily in each chamber. Temperature, pH and oxygen saturation were measured manually in each aquaria every day using a Mettler-Toledo S8 glass and a Fibox4 (PreSens) with an Oxygen Probe PSt3.

本研究报道了一项陆上实验的结果，该实验旨在探究铜（Cu）暴露与海洋酸化（OA）的联合累积效应。2019年4月，研究团队在圣马尤斯浅滩（Baixa de São Mateus）水深185米处开展试验性延绳钓渔业作业时，以副渔获物形式获取了实验用珊瑚；相关采样工作隶属于亚速尔大学的ARQDAÇO监测计划，作业平台为"阿尔基佩拉戈号"（R/V "Arquipélago"）科考船。本实验在亚速尔大学Okeanos实验室的DeepSeaLab水族养殖设施中开展，将珊瑚置于四种OA/Cu污染组合条件下暴露培养：(1) 原位实测的环境分压二氧化碳（pCO₂）/pH值水平（385 μatm，pH 8.09）；(2) 高pCO₂/低pH水平（对应政府间气候变化专门委员会（IPCC）RCP8.5情景，1000 μatm，pH 7.73）；(3) 环境pCO₂/pH水平外加60 μg/L的铜离子浓度；(4) 高pCO₂/低pH水平外加60 μg/L的铜离子浓度。pH与pCO₂的调控通过向海水中通入纯二氧化碳（以提升pCO₂水平）或低CO₂空气（以降低pCO₂水平）实现。本实验所用铜离子浓度参照了模拟潜在深海采矿事件中多金属颗粒羽流释放的预实验结果，该亚致死浓度为当前已知的海水中溶解铜的最高浓度水平。每日对各培养舱内海水的理化参数进行测定。研究人员每日使用梅特勒-托利多S8酸度计以及搭载PSt3氧电极的Fibox4（PreSens品牌），手动测定各水族箱内的水温、pH值与氧饱和度。