Seaweed fails to prevent ocean acidification impact on foraminifera along a shallow-water CO2 gradient

• Main Authors: Pettit, Laura Rachel, Smart, Christopher W, Hart, Malcom B, Milazzo, Marco, Hall-Spencer, Jason M
• Format: Dataset
• Language: English
• Published: PANGAEA 2015
• Subjects: Adelosina longirostra; Affinetrina gualtieriana; Alkalinity; total; Aragonite saturation state; Benthos; Bicarbonate ion; Biomass/Abundance/Elemental composition; Bolivina pseudoplicata; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; CO2 vent; Coast and continental shelf; Community composition and diversity; Cornuspira involvens; Daitrona sp.; Elphidium advenum; Elphidium crispum; Elphidium macellum; Elphidium margaritaceum; Elphidium sp.; Entire community; Field observation; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Haynesina depressula; Identification; Individuals; Lobatula lobatula; Massilina gualtieriana; Mediterranean Sea; Miliolinella sp.; Miliolinella subrotunda; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Peneroplis pertusus; Peneroplis planatus; Percentage; pH; Pileolina patelliformis; Potentiometric; Potentiometric titration; Pseudotriloculina sp.; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.846530; https://doi.org/10.1594/PANGAEA.846530

Ocean acidification causes biodiversity loss, alters ecosystems, and may impact food security, as shells of small organisms dissolve easily in corrosive waters. There is a suggestion that photosynthetic organisms could mitigate ocean acidification on a local scale, through seagrass protection or seaweed cultivation, as net ecosystem organic production raises the saturation state of calcium carbonate making seawater less corrosive. Here, we used a natural gradient in calcium carbonate saturation, caused by shallow-water CO2 seeps in the Mediterranean Sea, to assess whether seaweed that is resistant to acidification (Padina pavonica) could prevent adverse effects of acidification on epiphytic foraminifera. We found a reduction in the number of species of foraminifera as calcium carbonate saturation state fell and that the assemblage shifted from one dominated by calcareous species at reference sites (pH 8.19) to one dominated by agglutinated foraminifera at elevated levels of CO2 (pH 7.71). It is expected that ocean acidification will result in changes in foraminiferal assemblage composition and agglutinated forms may become more prevalent. Although Padina did not prevent adverse effects of ocean acidification, high biomass stands of seagrass or seaweed farms might be more successful in protecting epiphytic foraminifera.