Plocamium: pH drift: Carbonate chemistry over a time-course in pH drift experiments with Plocamium growth collected at Catalina Island, 2014-2015 (Seaweed OA Resilience project)

Rapid Light Curves_PAM: Measurements of fluorescence of photosystem II in Plocamium cartilagineum under various and pCO2 and temperature conditions

13:T4c7,

Plocamium cartilagineum was collected from Santa Catalina Island and Leo Carollo, CA in June - Nov. 2014 and Jan. 2015.

Carbonate chemistry parameters were measured by sampling pH and total alkalinity (TA) of water samples. Seawater samples from each culture pot during all 7 trials were collected approximately every other day in 50 ml Falcon tubes to verify experimental treatment conditions. Water samples were measured usually within 1-2 hours of sample collection. pH was determined using the m-cresol indicator dye method in a spectrophotometer (Dickson et al. 2007). TA samples were analyzed by potentiometric titration coupled to a pH electrode calibrated using certified reference material (CRM) from the Dickson laboratory at Scripps Oceanographic Institute and the pH electrode calibrated using TRIS buffer (Dickson et al. 2007). TA and carbonate parameters were calculated from potentiometric titration data and spectrophotometric pH data.

Note: Trial 1 was a pilot test of culture system and methodological procedures so was not used for data collection in the testing of hypotheses.

See Supplemental Files for a table of culture conditions for each of the 8 trials (pdf).

14:T4c6,Notes: Trial 1 was a pilot test of culture system and methodological procedures so was not used for data collection in the testing of hypotheses. In each culture pot, pCO2 was set by the supply rate of CO2 in the corresponding mass-flow controlled gas mixing system to be within a target range of either near ambient, moderately elevated or highly elevated in each t