Community-level sensitivity of a calcifying ecosystem to acute in situ CO2 enrichment

• Main Authors: Burdett, H L, Perna, G, McKay, Lucy, Broomhead, Gemma, Kamenos, N A
• Format: Dataset
• Language: English
• Published: PANGAEA 2018
• Subjects: Alkalinity; total; standard deviation; Aragonite saturation state; Benthos; Bicarbonate ion; Calcification/Dissolution; Calcification rate of calcium carbonate; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Containers and aquaria (20-1000 L or < 1 m**2); Dimethyl sulfide + Dimethylsulfoniopropionate; flux; Entire community; Estuary; EXP; Experiment; Field experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Fugacity of carbon dioxide in seawater; Irradiance; Loch_Sween; Nitrate; North Atlantic
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.902426; https://doi.org/10.1594/PANGAEA.902426

The rate of change in ocean carbonate chemistry is a vital determinant in the magnitude of effects observed. Benthic marine ecosystems are facing an increasing risk of acute CO2 exposure that may be natural or anthropogenically derived (e.g. engineering and industrial activities). However, our understanding of how acute CO2 events impact marine life is restricted to individual organisms, with little understanding for how this manifests at the community level. Here, we investigated in situ the effect of acute CO2 enrichment on the coralline algal ecosystem—a globally ubiquitous, ecologically and economically important habitat, but one which is likely to be sensitive to CO2 enrichment due to its highly calcified reef-like structures engineered by coralline algae. Most notably, we observed a rapid community-level shift to favour net dissolution rather than net calcification. Smaller changes from net respiration to net photosynthesis were also observed. There was no effect on the net flux of DMS/DMSP (algal secondary metabolites), nor on the nutrients nitrate and phosphate. Following return to ambient CO2 levels, only a partial recovery was seen within the monitoring timeframe. This study highlights the sensitivity of biogenic carbonate marine communities to acute CO2 enrichment and raises concerns over the capacity for the system to 'bounce back' if subjected to repeated acute high-CO2 events.