Seawater carbonate chemistry and community composition and production of of algal communities

• Main Authors: Harvey, Ben P, Kon, Koetsu, Agostini, Sylvain, Wada, Shigeki, Hall-Spencer, Jason M
• Format: Dataset
• Language: English
• Published: PANGAEA 2021
• Subjects: Abundance; Alkalinity; total; standard deviation; Aragonite saturation state; Benthos; Bicarbonate ion; 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; Complexity; Coverage; Entire community; EXP; Experiment; Experiment duration; Field experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gross community production of oxygen; Net community production; oxygen; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.930056; https://doi.org/10.1594/PANGAEA.930056

Long‐term exposure to CO2‐enriched waters can considerably alter marine biological community development, often resulting in simplified systems dominated by turf algae that possess reduced biodiversity and low ecological complexity. Current understanding of the underlying processes by which ocean acidification alters biological community development and stability remains limited, making the management of such shifts problematic. Here, we deployed recruitment tiles in reference (pHT 8.137 +/- 0.056 SD) and CO2‐enriched conditions (pHT 7.788 +/- 0.105 SD) at a volcanic CO2 seep in Japan to assess the underlying processes and patterns of algal community development. We assessed (i) algal community succession in two different seasons (Cooler months: January–July, and warmer months: July–January), (ii) the effects of initial community composition on subsequent community succession (by reciprocally transplanting preestablished communities for a further 6 months), and (iii) the community production of resulting communities, to assess how their functioning was altered (following 12 months recruitment). Settlement tiles became dominated by turf algae under CO2‐enrichment and had lower biomass, diversity and complexity, a pattern consistent across seasons. This locked the community in a species‐poor early successional stage. In terms of community functioning, the elevated pCO2 community had greater net community production, but this did not result in increased algal community cover, biomass, biodiversity or structural complexity. Taken together, this shows that both new and established communities become simplified by rising CO2 levels. Our transplant of preestablished communities from enriched CO2 to reference conditions demonstrated their high resilience, since they became indistinguishable from communities maintained entirely in reference conditions. This shows that meaningful reductions in pCO2 can enable the recovery of algal communities. By understanding the ecological processes responsible for driving shifts in ...