Inorganic nutrient concentrations in seawater during a multi-stressor ex-situ aquarium 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. Concentrations of dissolved nitrates, nitrite, silicate and phosphate were analysed from each experimental aquaria after one, six and nine months. Inorganic nutrient concentrations in seawater were determined using a SFA (Segmented Flow Autoanalyzer) (Aminot & Kérouel, 2007) with a SEAL Analytical QuAAtro analyzer using established colorimetric methods (Hydes et al. 2010 & Becker et al. 2020). RMNs (Reference Material for nutrients in seawater) with different concentration ranges were used for quality control and accuracy of our analysis. Low nutrient seawater (surface seawater filtered and aged) is also used to control low nutrient concentrations.