Publication Date:
2024-03-15
Description:
The response of respiration, photosynthesis, and calcification to elevated pCO2 and temperature was investigated in isolation and in combination in the Mediterranean crustose coralline alga Lithophyllum cabiochae. Algae were maintained in aquaria during 1 year at near-ambient conditions of irradiance, at ambient or elevated temperature (+3 °C), and at ambient (ca. 400 µatm) or elevated pCO2 (ca. 700 µatm). Respiration, photosynthesis, and net calcification showed a strong seasonal pattern following the seasonal variations of temperature and irradiance, with higher rates in summer than in winter. Respiration was unaffected by pCO2 but showed a general trend of increase at elevated temperature at all seasons, except in summer under elevated pCO2. Conversely, photosynthesis was strongly affected by pCO2 with a decline under elevated pCO2 in summer, autumn, and winter. In particular, photosynthetic efficiency was reduced under elevated pCO2. Net calcification showed different responses depending on the season. In summer, net calcification increased with rising temperature under ambient pCO2 but decreased with rising temperature under elevated pCO2. Surprisingly, the highest rates in summer were found under elevated pCO2 and ambient temperature. In autumn, winter, and spring, net calcification exhibited a positive or no response at elevated temperature but was unaffected by pCO2. The rate of calcification of L. cabiochae was thus maintained or even enhanced under increased pCO2. However, there is likely a trade-off with other physiological processes. For example, photosynthesis declines in response to increased pCO2 under ambient irradiance. The present study reports only on the physiological response of healthy specimens to ocean warming and acidification, however, these environmental changes may affect the vulnerability of coralline algae to other stresses such as pathogens and necroses that can cause major dissolution, which would have critical consequence for the sustainability of coralligenous habitats and the budgets of carbon and calcium carbonate in coastal Mediterranean ecosystems.
Keywords:
Alkalinity, total; Alkalinity, total, standard error; Alkalinity anomaly technique (Smith and Key, 1975); Aragonite saturation state; Aragonite saturation state, standard error; Benthos; Bicarbonate ion; Bicarbonate ion, standard error; Calcification/Dissolution; Calcite saturation state; Calcite saturation state, standard deviation; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate ion, standard error; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard error; Coast and continental shelf; Containers and aquaria (20-1000 L or 〈 1 m**2); EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gross calcification rate of calcium carbonate; Gross calcification rate of calcium carbonate, standard error; Gross photosynthesis rate, carbon dioxide; Gross photosynthesis rate, carbon dioxide, standard error; Gross photosynthesis rate, oxygen; Gross photosynthesis rate, oxygen, standard error; Identification; Irradiance; Laboratory experiment; Lithophyllum cabiochae; Macroalgae; Mediterranean Sea; Mediterranean Sea Acidification in a Changing Climate; MedSeA; Net calcification rate of calcium carbonate; Net calcification rate of calcium carbonate, standard error; Net photosynthesis rate, carbon dioxide; Net photosynthesis rate, carbon dioxide, standard error; Net photosynthesis rate, oxygen; Net photosynthesis rate, oxygen, standard error; North Atlantic; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Partial pressure of carbon dioxide (water) at sea surface temperature (wet air), standard error; pH; Plantae; Primary production/Photosynthesis; Respiration; Respiration rate, carbon dioxide; Respiration rate, carbon dioxide, standard error; Respiration rate, oxygen; Respiration rate, oxygen, standard error; Rhodophyta; Salinity; Season; Single species; Species; Temperate; Temperature; Temperature, water; Treatment; Tropical; Villefranche
Type:
Dataset
Format:
text/tab-separated-values, 14036 data points
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