Seawater carbonate chemistry and photosynthetic and calcification rate of the free-living coralline algae Phymatolithon lusitanicum, supplement to: Sordo, Laura; Santos, Rui; Barrote, Isabel; Silva, João (2018): High CO2 decreases the long-term resilience of the free-living coralline algae Phymatolithon lusitanicum. Ecology and Evolution, 8(10), 4781-4792

• Main Authors: Sordo, Laura, Santos, Rui, Barrote, Isabel, Silva, João
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2018
• Subjects: Benthos; Calcification/Dissolution; Coast and continental shelf; Containers and aquaria 20-1000 L or < 1 m**2; Growth/Morphology; Laboratory experiment; Macroalgae; North Atlantic; Phymatolithon lusitanicum; Plantae; Primary production/Photosynthesis; Rhodophyta; Single species; Temperate; Type; Species; Registration number of species; Uniform resource locator/link to reference; Experiment duration; Partial pressure of carbon dioxide water at sea surface temperature wet air; Irradiance; Net photosynthesis rate, oxygen; Net photosynthesis rate, oxygen, standard error; Calcification rate of calcium carbonate; Calcification rate, standard error; Duration; Calcification rate, standard deviation; Growth, cumulative, per wet mass; Growth, cumulative, per wet mass, standard deviation; Alkalinity, total; Alkalinity, total, standard error; Salinity; Salinity, standard error; Temperature, water; Temperature, water, standard error; pH; pH, standard error; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard error; Aragonite saturation state; Aragonite saturation state, standard error; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Calcite saturation state; Experiment; Buoyant weighing technique Davies, 1989; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.892895; https://doi.pangaea.de/10.1594/PANGAEA.892895

Mäerl/rhodolith beds are protected habitats that may be affected by ocean acidification (OA), but it is still unclear how the availability of CO2 will affect the metabolism of these organisms. Some of the inconsistencies found among OA experimental studies may be related to experimental exposure time and synergetic effects with other stressors. Here, we investigated the long‐term (up to 20 months) effects of OA on the production and calcification of the most common mäerl species of southern Portugal, Phymatolithon lusitanicum. Both the photosynthetic and calcification rates increased with CO2 after the first 11 months of the experiment, whereas respiration slightly decreased with CO2. After 20 months, the pattern was reversed. Acidified algae showed lower photosynthetic and calcification rates, as well as lower accumulated growth than control algae, suggesting that a metabolic threshold was exceeded. Our results indicate that long‐term exposure to high CO2 will decrease the resilience of Phymatolithon lusitanicum. Our results also show that shallow communities of these rhodoliths may be particularly at risk, while deeper rhodolith beds may become ocean acidification refuges for this biological community. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2016) 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 2018-08-06.