Dataset: Water chemistry during mesocosm study of trophic interactions under ocean acidification in Bodega Bay, CA.

This dataset is part of a larger experiment to investigate how pH influences trophic links between intertidal sea stars (Leptasterias hexactis), snails (Tegula funebralis), and macroalgae (Mazzaella flaccida). Organisms were placed for 7 days in mesocosms containing seawater at either ambient (~7.9) or low pH (~7.0). The pH was modified using equimolar additions of sodium bicarbonate (NaHCO3) and hydrochloric acid (HCl). The water in each container was changed daily. The mesocosm array consisted of 40, 13-liter (L) circular plastic containers with a mesh barrier down the center to separate predator, prey, and/or basal resource but allowing for passage of waterborne cue. Mesocosms were filled halfway with seawater, allowing 10 centimeter (cm) of refuge space for snails above the waterline. Mesocosms were held within a seawater table under constant flow to maintain consistent temperatures.

Temperature, salinity, dissolved oxygen, and pH were measured using a YSI ProPlus Sensor.

Total pH was measured using a Sunburst SAMI spectrophotometric unit modified for benchtop use.

Total alkalinity was measured via Gran titration (Riebesell et al. 2010) standardized using certified reference material (A. Dickson, Scripps Institution of Oceanography) using a Metrohm 855 autotitrator.

Values of total pH for each container were measured using a YSI ProPlus Sensor and calibrated to the total scale using daily samples run on a Sunburst SAMI spectrophotometric unit modified for benchtop use.