Description: 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.

Description: 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.

Description: 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), from the 6th of May 2022 to the 24th of February 2023. 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. This dataset contains the registered values for temperature, pH, DO (% air saturation and mg/L) and sainity from the experimental aquarium over the course of the experiment. Temperature and DO were daily measured with a YSI ProODO dissolved oxygen instrument. Salinity was weekly assessed with a WTW 350i multiparameter device equipped with a ConOx probe. Measurements for pH were performed every 1 – 2 months. Samples for pH were directly collected on cylindrical 10 cm cuvettes and analysed on daily basis. After being thermostated at 25ºC, samples were measured using a manual spectrophotometrical procedure with a Sigma Aldrich impure indicator (Clayton and Byrne, 1993). The uncertainty of pH is about 0.005 pH units.

Description: 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. Measurements for pH and total alkalinity (TA) were performed on seawater samples from all the experimental aquaria every 1 – 2 months. Samples for pH were directly collected on cylindrical 10 cm cuvettes and analysed on daily basis. After being thermostated at 25ºC, samples were measured using a manual spectrophotometrical procedure with a Sigma Aldrich impure indicator (Clayton and Byrne, 1993). TA was measured following the double end point potentiometric technique by Pérez and Fraga (1987a) and Pérez et al. (2000). Measurements of Certified Reference Material (Dickson's lab, SIO) were performed in order to control the accuracy of the TA measurements. The uncertainty of TA and pH is about 3 μmol/kg and 0.005 pH units, respectively. In situ additional CO2 system variables were calculated using the R package seacarb (Gattuso et al. 2023) using in situ temperature, salinity, measured pH and TA, the dissociation constants of carbonic acid in seawater (K1 and K2) by Lueker et al. (2000), the equilibrium constant of hydrogen fluoride by Perez and Fraga (1987b), the concentration of total boron by Uppström (1974) formulation, and the stability constant of hydrogen sulphate by Dickson (1990). Mean values for the concentration of silicate and phosphate on the aquaria experiments were used in the CO2 calculations, respectively, mean (and standard) deviations as 2.1 (0.4) and 0.31 (0.03) μmol/kg.

Description: 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. Raspberry-based controllers were set to modify and monitor the water temperature, pH and dissolved oxygen in every treatment. Values for temperature (ºC), pH (NBS scale) and oxygen (% air saturation) were registered every 15 minutes in a database. The parameters were measured using PT100 temperature sensors, and Atlas Scientific Lab Grade pH and Dissolved Oxygen sensors. Every set of sensors was placed on each header tank, corresponding to each treatment (8 in total). Parameter setpoint values for each header tank were finely adjusted on the controller to ensure the treatment target values on each experimental aquaria. Oxygen sensors from treatments with ambient oxygen (~8.63 mg/L) were removed from the system due to calibration issues. Here, an example of the results for temperature, pH and oxygen for every header tank over 24 hours on 31st of December 2022 is presented. Values for pH (total scale) and dissolved oxygen (mg/L) were calculated using AquaEnv (Hofmann et al. 2010) and respR (Harianto et al. 2019) R packages, respectively, using the in situ temperature and salinity (35.1).