Seawater carbonate chemistry and macrofaunal community structure and behavior

• Main Authors: Godbold, Jasmin A, Hale, Rachel, Wood, Christina L, Solan, Martin
• Format: Dataset
• Language: English
• Published: PANGAEA 2023
• Subjects: Alkalinity; total; Ammonium; Aragonite saturation state; Benthos; Bicarbonate ion; Biomass; wet mass; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria (<20 L); Bromide; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; organic; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Community composition and diversity; Core; Entire community; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Individuals; Laboratory experiment; Macrofauna; abundance; Mixing depth; Nitrate and Nitrite; North Atlantic; OA-ICC; Ocean Acidification International Coordination Centre; Other studied parameter or process; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Phosphate; Potentiometric; Potentiometric titration; Replicate; Salinity; Site; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.958993; https://doi.org/10.1594/PANGAEA.958993

Fundamental changes in seawater carbonate chemistry and sea surface temperatures associated with the ocean uptake of anthropogenic CO2 are accelerating, but investigations of the susceptibility of biogeochemical processes to the simultaneous occurrence of multiple components of climate change are uncommon. Here, we quantify how concurrent changes in enhanced temperature and atmospheric pCO2, coupled with an associated shift in macrofaunal community structure and behavior (sediment particle reworking and bioirrigation), modify net carbon and nutrient concentrations (NH4-N, NOx-N, PO4-P) in representative shelf sea sediment habitats (mud, sandy-mud, muddy-sand and sand) of the Celtic Sea. We show that net concentrations of organic carbon, nitrogen and phosphate are, irrespective of sediment type, largely unaffected by a simultaneous increase in temperature and atmospheric pCO2. However, our analyses also reveal that a reduction in macrofaunal species richness and total abundance occurs under future environmental conditions, varies across a gradient of cohesive to non-cohesive sediments, and negatively moderates biogeochemical processes, in particular nitrification. Our findings indicate that future environmental conditions are unlikely to have strong direct effects on biogeochemical processes but, particularly in muddy sands, the abundance, activity, composition and functional role of invertebrate communities are likely to be altered in ways that will be sufficient to regulate the function of the microbial community and the availability of nutrients in shelf sea waters.