Presence of competitors influences photosynthesis, but not growth, of the hard coral Porites cylindrica at elevated seawater CO2, supplement to: Brien, H V; Watson, Sue-Ann; Hoogenboom, M O (2016): Presence of competitors influences photosynthesis, but not growth, of the hard coral Porites cylindrica at elevated seawater CO2. ICES Journal of Marine Science, 73(3), 659-669

• Main Authors: Brien, H V, Watson, Sue-Ann, Hoogenboom, M O
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2016
• Subjects: Acropora cerealis; Animalia; Benthic animals; Benthos; Cnidaria; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Growth/Morphology; Laboratory experiment; Porites cylindrica; Primary production/Photosynthesis; Sarcophyton sp.; Sinularia sp.; South Pacific; Species interaction; Tropical; Type; Species; Registration number of species; Uniform resource locator/link to reference; Figure; Treatment; Maximum photochemical quantum yield of photosystem II; Maximum photochemical quantum yield of photosystem II, standard deviation; Maximum photochemical quantum yield of photosystem II, standard error; Replicates; Counts; Position; Effective quantum yield; Effective quantum yield, standard deviation; Effective quantum yield, standard error; Growth rate; Growth rate, standard deviation; Growth rate, standard error; Biomass; Biomass, standard deviation; Biomass, standard error; Sclerite density; Sclerite density, standard deviation; Sclerite density, standard error; Temperature, water; Temperature, water, standard error; Salinity; 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; Aragonite saturation state; Aragonite saturation state, standard error; Bicarbonate ion; Bicarbonate ion, standard error; Carbonate ion; Carbonate ion, standard error; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Carbon, inorganic, dissolved; Calcite saturation state; Potentiometric; Potentiometric titration; 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.865330; https://doi.pangaea.de/10.1594/PANGAEA.865330

Changes in environmental conditions, such as those caused by elevated carbon dioxide (CO2), potentially alter the outcome of competitive interactions between species. This study aimed to understand how elevated CO2 could influence competitive interactions between hard and soft corals, by investigating growth and photosynthetic activity of Porites cylindrica (a hard coral) under elevated CO2 and in the presence of another hard coral and two soft coral competitors. Corals were collected from reefs around Orpheus and Pelorus Islands on the Great Barrier Reef, Australia. They were then exposed to elevated pCO2 for 4 weeks with two CO2 treatments: intermediate (pCO2 648) and high (pCO2 1003) compared with a control (unmanipulated seawater) treatment (pCO2 358). Porites cylindrica growth did not vary among pCO2 treatments, regardless of the presence and type of competitors, nor was the growth of another hard coral species, Acropora cerealis, affected by pCO2 treatment. Photosynthetic rates of P. cylindrica were sensitive to variations in pCO2, and varied between the side of the fragment facing the competitors vs. the side facing away from the competitor. However, variation in photosynthetic rates depended on pCO2 treatment, competitor identity, and whether the photosynthetic yields were measured as maximum or effective photosynthetic yield. This study suggests that elevated CO2 may impair photosynthetic activity, but not growth, of a hard coral under competition and confirms the hypothesis that soft corals are generally resistant to elevated CO2. Overall, our results indicate that shifts in the species composition in coral communities as a result of elevated CO2 could be more strongly related to the individual tolerance of different species rather than a result of competitive interactions between species. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2015) 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 is 2016-09-12.