Prokariotic abundances during a multi-stressor aquaria experiment with the cold-water coral Dendrophyllia cornigera

A 9-month aquarium experiment with the cold-water Dendrophyllia cornigera was conducted to investigate the single and combined effects of warming, acidification and deoxygenation on its ecophysiological response. The experiment took place at the Aquarium finisterrae (A Coruña, Spain) between 2022-05-06 and 2023-02-24. Treatment values for each parameter (current in situ vs. climate change) were: 12 °C and 15 °C (temperature); ~7.99 and 7.69 (pH); ~8.63 mg/L and 6.45 mg/L (dissolved oxygen concentration). A total of eight treatments (with 3 replicates each, 5 L aquaria) were set up. Prokaryotes were quantified by flow citometry (CytoFLEXflex S, Beckman Coulter) as previously described by Gasol et al. (1999) with our own adjustment of the scatter settings to more accurately resolve these cells with the new CytoFLEX flow cytometry technology. Measurements were performed every month from different parts of the aquaria setup: the input seawater, the reservoir tank (after the filtration of seawater to 5 µm and before the UV lamp) and every experimental aquaria.

本研究以冷水性角孔珊瑚（Dendrophyllia cornigera）为研究对象，开展了为期9个月的受控水族箱实验，旨在探究升温、海洋酸化与溶解氧降低的单一及联合作用对其生态生理响应的影响。实验于2022年5月6日至2023年2月24日在西班牙拉科鲁尼亚的菲尼斯特雷水族馆（Aquarium Finisterrae）内完成。本实验针对各环境参数设置了两组处理（原位当前环境与气候变化情景），对应参数分别为：温度12 ℃与15 ℃；pH值约7.99与7.69；溶解氧浓度约8.63 mg/L与6.45 mg/L。共设置8组实验处理，每组设置3个生物学重复，实验容器为5 L规格的水族箱。原核生物丰度采用流式细胞术（flow cytometry，CytoFLEXflex S，贝克曼库尔特（Beckman Coulter））进行定量，参照Gasol等（1999）的经典方法，并针对新型CytoFLEX流式细胞仪技术调整了散射光参数，以更精准地分辨此类微生物细胞。研究人员每月从水族箱系统的不同点位采集样本进行测定，包括输入海水、储水箱（海水经5 µm过滤后、紫外消毒灯处理前）以及所有实验水族箱内的水体。