Publication Date:
2024-03-15
Description:
The supply of metabolites from symbionts to scleractinian corals is crucial to coral health. Members of the Symbiodiniaceae can enhance coral calcification by providing photosynthetically fixed carbon (PFC) and energy, whereas dinitrogen (N2)-fixing bacteria can provide additional nutrients such as diazotrophically-derived nitrogen (DDN) that sustain coral productivity especially when alternative external nitrogen sources are scarce. How these mutualistic associations benefit corals in the future acidifying ocean is not well understood. In this study, we investigated the possible effects of ocean acidification (OA; pHs 7.7 and 7.4 vs. 8.1) on calcification in the hermatypic coral Galaxea fascicularis with respect to PFC and DDN assimilation. Our measurements based on isotopic tracing showed no significant differences in the assimilation of PFC among different pH treatments, but the assimilation of DDN decreased significantly after 28 days of stress at pH 7.4. The decreased DDN assimilation suggests a nitrogenous nutrient deficiency in the coral holotiont, potentially leading to reduced coral calcification and resilience to bleaching and other stressful events. This contrasting impact of OA on carbon and N flux demonstrates the flexibility of G. fascicularis in coping with OA, apparently by sustaining a largely undamaged photosystem at the expense of N2 fixation machinery, which competes with coral calcification for energy from photosynthesis. These findings shed new light on the critically important but more vulnerable N cycling in hospite, and on the trade-off between coral hosts and symbionts in response to future climate change.
Keywords:
Alkalinity, total; Alkalinity, total, standard deviation; Ammonium; Ammonium, standard deviation; Animalia; Aragonite saturation state; Aragonite saturation state, standard deviation; Benthic animals; Benthos; Bicarbonate ion; Bicarbonate ion, standard deviation; Calcification/Dissolution; Calcification rate; Calcification rate, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Cnidaria; Coast and continental shelf; Containers and aquaria (20-1000 L or 〈 1 m**2); Diazotrophically-derived nitrogen assimilation rate, nitrogen in tracer/nitrogen in tissue; Diazotrophically-derived nitrogen assimilation rate, nitrogen in tracer/nitrogen in tissue, standard deviation; Effective quantum yield; Effective quantum yield, standard deviation; Experiment duration; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Fugacity of carbon dioxide in seawater, standard deviation; Galaxea fascicularis; Laboratory experiment; Maximum quantum yield of photosystem II; Maximum quantum yield of photosystem II, standard deviation; Nitrate; Nitrite; Nitrite, standard deviation; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Other metabolic rates; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; pH, standard deviation; Phosphate; Phosphate, standard deviation; Photosynthetically fixed carbon assimilation rate, carbon in tracer/carbon in tissue; Photosynthetically fixed carbon assimilation rate, carbon in tracer/carbon in tissue, standard deviation; Potentiometric; Potentiometric titration; Primary production/Photosynthesis; Registration number of species; Salinity; Salinity, standard deviation; Silicate; Silicate, standard deviation; Single species; Species; Temperature, water; Temperature, water, standard deviation; Treatment; Tropical; Type; Uniform resource locator/link to reference; δ13C; δ13C, standard deviation; δ15N; δ15N, standard deviation
Type:
Dataset
Format:
text/tab-separated-values, 555 data points
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