Seawater carbonate chemistry and net calcification, relative electron transport rates and photosynthetic pigments of Porolithon onkodes

• Main Authors: Johnson, Maggie Dorothy, Carpenter, Robert C
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2018
• Subjects: Animalia; Benthic animals; Benthos; Calcification/Dissolution; Cnidaria; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Laboratory experiment; Macro-nutrients; Porolithon onkodes; Primary production/Photosynthesis; Single species; South Pacific; Tropical; Type; Species; Registration number of species; Uniform resource locator/link to reference; Identification; Treatment; Calcification rate; Electron transport rate, relative; Chlorophyll a; Phycocyanin; Phycoerythrin; Temperature, water; Temperature, water, standard error; Salinity; Salinity, standard error; Irradiance; Irradiance, standard error; Flow rate; Flow rate, standard error; pH; pH, standard error; Alkalinity, total; Alkalinity, total, standard error; 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; Calcite saturation state; Calcite saturation state, standard error; Nitrate and Nitrite; Nitrate and Nitrite, standard error; Ammonium; Ammonium, standard error; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Carbon, inorganic, dissolved; Aragonite saturation state; Experiment; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.924886; https://doi.pangaea.de/10.1594/PANGAEA.924886

Ocean acidification (OA) and nutrient enrichment threaten the persistence of near shore ecosystems, yet little is known about their combined effects on marine organisms. Here, we show that a threefold increase in nitrogen concentrations, simulating enrichment due to coastal eutrophication or consumer excretions, offset the direct negative effects of near-future OA on calcification and photophysiology of the reef-building crustose coralline alga, Porolithon onkodes. Projected near-future pCO2 levels (approx. 850 µatm) decreased calcification by 30% relative to ambient conditions. Conversely, nitrogen enrichment (nitrate + nitrite and ammonium) increased calcification by 90–130% in ambient and high pCO2 treatments, respectively. pCO2 and nitrogen enrichment interactively affected instantaneous photophysiology, with highest relative electron transport rates under high pCO2 and high nitrogen. Nitrogen enrichment alone increased concentrations of the photosynthetic pigments chlorophyll a, phycocyanin and phycoerythrin by approximately 80–450%, regardless of pCO2. These results demonstrate that nutrient enrichment can mediate direct organismal responses to OA. In natural systems, however, such direct benefits may be counteracted by simultaneous increases in negative indirect effects, such as heightened competition. Experiments exploring the effects of multiple stressors are increasingly becoming important for improving our ability to understand the ramifications of local and global change stressors in near shore ecosystems. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2020) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2020-11-11.