Seawater carbonate chemistry and grazing and diet preference in Littorina littorea

• Main Authors: Ober, Gordon T, Thornber, Carol S, Grear, Jason S
• Format: Dataset
• Language: English
• Published: PANGAEA 2022
• Subjects: Alkalinity; total; standard error; Animalia; Aragonite saturation state; Behaviour; Benthic animals; Benthos; Bicarbonate ion; 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; Change; Chlorophyta; Coast and continental shelf; Containers and aquaria (20-1000 L or < 1 m**2); EXP; Experiment; Fucus vesiculosus; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Grazing rate per individual; Identification; Laboratory experiment; Littorina littorea; Macroalgae; Macro-nutrients; Mollusca; Nitrogen; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.951529; https://doi.org/10.1594/PANGAEA.951529

Ocean acidification and eutrophication have direct, positive effects on the growth of many marine macroalgae, potentially resulting in macroalgal blooms and shifts in ecosystem structure and function. Enhanced growth of macroalgae, however, may be controlled by the presence of grazers. While grazing under ocean acidification and eutrophication conditions has variable responses, there is evidence of these factors indirectly increasing consumption. We tested whether a common marine herbivorous snail, Littorina littorea, would increase consumption rates of macroalgae (Ulva and Fucus) under ocean acidification (increased pCO2) and/or eutrophication conditions, via feeding trials on live and reconstituted algal thalli. We found that increased pCO2 resulted in reduced grazing rates on live thalli, with snails feeding almost exclusively on Ulva. However, eutrophication did not impact consumption rates of live tissues. In addition, similarity in consumption of reconstituted Ulva and Fucus tissues across all treatments indicated that physical characteristics of algal tissues, rather than tissue chemistry, may drive dietary shifts in a changing climate. In this system, decreased consumption, coupled with increased growth of macroalgae, may ultimately enhance algal growth and spread.