Publication Date:
2024-05-22
Description:
Zooxanthellate colonies of the scleractinian coral Astrangia poculata were grown under combinations of ambient and elevated nutrients (5 µM NO, 0.3 µM PO4, and 2nM Fe) and CO2 (780 ppmv) treatments for a period of 6 months. Coral calcification rates, estimated from buoyant weights, were not significantly affected by moderately elevated nutrients at ambient CO2 and were negatively affected by elevated CO2 at ambient nutrient levels. However, calcification by corals reared under elevated nutrients combined with elevated CO2 was not significantly different from that of corals reared under ambient conditions, suggesting that CO2 enrichment can lead to nutrient limitation in zooxanthellate corals. A conceptual model is proposed to explain how nutrients and CO2 interact to control zooxanthellate coral calcification. Nutrient limited corals are unable to utilize an increase in dissolved inorganic carbon (DIC) as nutrients are already limiting growth, thus the effect of elevated CO2 on saturation state drives the calcification response. Under nutrient replete conditions, corals may have the ability to utilize more DIC, thus the calcification response to CO2 becomes the product of a negative effect on saturation state and a positive effect on gross carbon fixation, depending upon which dominates, the calcification response can be either positive or negative. This may help explain how the range of coral responses found in different studies of ocean acidification can be obtained.
Keywords:
Alkalinity, Gran titration (Gran, 1950); Alkalinity, total; Alkalinity, total, standard deviation; Animalia; Aragonite saturation state; Astrangia poculata; Benthic animals; Benthos; Bicarbonate ion; Bottles or small containers/Aquaria (〈20 L); Buoyant weighing technique according to Davies (1989); Calcification/Dissolution; Calcification rate; Calcification rate, standard deviation; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, partial pressure, standard deviation; Cnidaria; Coast and continental shelf; Continuous flow injection system, FIAlab 2600; EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; Experimental treatment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Hach conductivity probe; Infrared pCO2 analyzer (Qubit S151); Laboratory experiment; Macro-nutrients; Nitrate and Nitrite; Nitrate and Nitrite, standard deviation; Onset logger; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Phosphate; Phosphate, standard deviation; Salinity; Salinity, standard deviation; Silicate; Silicon, standard deviation; Single species; Temperate; Temperature, standard deviation; Temperature, water
Type:
Dataset
Format:
text/tab-separated-values, 104 data points
Permalink
