KOSMOS 2020 Peru mesocosm study on ecosystem responses to different light and upwelling intensities: inorganic nutrient concentrations of water samples

• Main Authors: Varmanen, Pia, Thielecke, Antonia, Meyer, Jana, Ludwig, Andrea, Spilling, Kristian
• Format: Dataset
• Language: English
• Published: PANGAEA 2023
• Subjects: Ammonium; AQUACOSM; Coastal Upwelling System in a Changing Ocean; Comment; CUSCO; DATE/TIME; Day of experiment; Depth; water; experiment; bottom/maximum; top/minimum; Event label; Field experiment; Humboldt Current System; inorganic nutrients; KOSMOS_2020; KOSMOS_2020_Mesocosm-M1; KOSMOS_2020_Mesocosm-M10; KOSMOS_2020_Mesocosm-M2; KOSMOS_2020_Mesocosm-M3; KOSMOS_2020_Mesocosm-M4; KOSMOS_2020_Mesocosm-M5; KOSMOS_2020_Mesocosm-M6; KOSMOS_2020_Mesocosm-M7; KOSMOS_2020_Mesocosm-M8; KOSMOS_2020_Mesocosm-M9; KOSMOS Peru; light limitation; MESO; Mesocosm experiment; Mesocosm label; mesocosm study; Network of Leading European AQUAtic MesoCOSM Facilities Connecting Mountains to Oceans from the Arctic to the Mediterranean; Nitrate; Nitrate and Nitrite; Nitrite; Phosphate; Silicate; Treatment; Treatment: light condition; Type of study; Upwelling; Arctic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.961217; https://doi.org/10.1594/PANGAEA.961217

This data is part of the BMBF project CUSCO (Coastal Upwelling Systems in a Changing Ocean). Here we report the inorganic nutrient concentrations during a 35-day experiment, where we enclosed natural plankton communities in in-situ mesocosms off Peru. The experiment investigated the interactive effects of light and upwelling on the Humboldt upwelling ecosystem by mimicking a gradient of upwelling intensities (0%, 15%, 30%, 45% and 60%) under summer-time high light and winter-time low light. Integrated seawater samples from a depth between 0 and 10m were collected using a 5L Integrating Water sampler (IWS; Hydro-Bios, Kiel). Water samples for inorganic nutrients were filtered (0.45 µm PTFE syringe filter, Merck Millex) and analysed in triplicates. Dissolved inorganic nutrients (nitrate, nitrite, phosphate, and dissolved silica were determined using a spectrophotometer (ShimadzuV-1800) and standard colorimetric methods (Grasshoff et al., 2009; DOI:10.1002/iroh.19850700232). Ammonium was determined fluorometrically. Due to the COVID-19 lockdown, we were not able to determine inorganic nutrients after day 17, and instead samples were frozen at -20°C after filtration and analysed with an autosampler (XY2 autosampler, SEAL Analytical) and a continuous flow analyzer (QuAAtro AutoAnalyzer, SEAL Analytical) connected to a fluorescence detector (FP-2020, JASCO).