Seawater carbonate chemistry and benthic marine community during experiments, 2011

• Main Authors: Kroeker, Kristy J, Micheli, Florenza, Gambi, Maria Cristina, Martz, Todd R
• Format: Dataset
• Language: English
• Published: PANGAEA 2011
• Subjects: Alkalinity; total; standard deviation; Amphipoda; Aragonite saturation state; Benthos; Bicarbonate ion; Biomass/Abundance/Elemental composition; Bivalvia; Calcite saturation state; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; partial pressure; CO2 vent; Coast and continental shelf; Community composition and diversity; Decapoda; Entire community; EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; Experimental treatment; Field observation; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gastropoda; Guildline autosal salinometer; Honeywell Durafet pH sensors; Isopoda; Mediterranean Sea; OA-ICC; Ocean Acidification International Coordination Centre; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.777433; https://doi.org/10.1594/PANGAEA.777433

Ocean acidification is predicted to impact all areas of the oceans and affect a diversity of marine organisms. However, the diversity of responses among species prevents clear predictions about the impact of acidification at the ecosystem level. Here, we used shallow water CO2 vents in the Mediterranean Sea as a model system to examine emergent ecosystem responses to ocean acidification in rocky reef communities. We assessed in situ benthic invertebrate communities in three distinct pH zones (ambient, low, and extreme low), which differed in both the mean and variability of seawater pH along a continuous gradient. We found fewer taxa, reduced taxonomic evenness, and lower biomass in the extreme low pH zones. However, the number of individuals did not differ among pH zones, suggesting that there is density compensation through population blooms of small acidification-tolerant taxa. Furthermore, the trophic structure of the invertebrate community shifted to fewer trophic groups and dominance by generalists in extreme low pH, suggesting that there may be a simplification of food webs with ocean acidification. Despite high variation in individual species' responses, our findings indicate that ocean acidification decreases the diversity, biomass, and trophic complexity of benthic marine communities. These results suggest that a loss of biodiversity and ecosystem function is expected under extreme acidification scenarios.