Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Supplemental Files
• Related Publications
• Parameters
• Instruments
• Project Information
• Program Information
• Funding

This dataset includes measurements of pH drift of seawater samples taken over 30-hour time periods in the presence or absence of Plocamium cartilagineum, with two carbonic anhydrase inhibitors, and with three pCO2 levels. Carbonate chemistry is reported at six time intervals.

Related Datasets:
Plocamium carbon nitrogen and stable isotopes: Plocamium carbon and nitrogen content and stable isotope values, 2014-2015 (Seaweed OA Resilience project)

Plocamium culture carbonate chemistry: Carbonate chemistry in experimental cultures of Plocamium cartilagineum cultured at different temperatures and pCO2 levels (Seaweed OA Resilience project)

Plocamium culture: seawater delta13C: Stable isotope ratio and concentration of carbon in seawater during Plocamium culture experiments, 2014-2015 (Seaweed OA Resilience project)

Plocamium cultures pH and temperature: Plocamium culture pot pH and temperature time-series at 10 minute sampling intervals from 2014-2015 (Seaweed OA Resilience project)

Plocamium exptl treatments summary: Summary of pCO2 and temperature treatment combinations for each culture pot and experimental trial (Seaweed OA Resilience project)

Plocamium growth and biomass: Experimental results of Plocamium cartilagineum growth and biomass as a function of pCO2 and temperature (Seaweed OA Resilience project)

Plocamium pigments: Photosynthetic pigment concentrations in Plocamium cartilagineum, trials 3-8, 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

Plocamium cartilagineum was collected from Catalina Island in June - Nov. 2014 and Jan. 2015.

Seawater samples were collected over a 30-hour time course of pH drift experiments with Plocamium cartilagineum to test mechanism of carbon acquisition by alga and the effect on carbonate chemistry parameters reported in these datasets. Samples were collected at 0, 2, 6, 20, 24 and 30 hours and parameters of carbonate chemistry were measured (DIC,CO2, HCO3,CO3-described below). pH drift assay experiments consisted of 2 independent variables; inhibitor treatment and algal presence, with 3 and 2 levels, respectively for each independent variable (see parameters section). Two replicate water samples were collected from each of 9 experimental culture pots of algae grown for 3 weeks at different combinations of pCO2 and temperature during each of 7 experimental trials.

Carbonate chemistry parameters were measured by sampling pH and total alkalinity (TA) of water samples. 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.

Methodology Reference:
Dickson AG, Sabine CL, Christian JR (2007). Guide to Best Practices for Ocean CO2 Measurements.

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).

Carbonate chemistry parameters (CO2 concentration, CO2 partial pressure, CO2 fugacity, HCO3, CO3, DIC, Omega Aragonite, Omega Calcite) and total scale pH at in situ temperature were calculated using the seacarb package (V3.0.14) in R (Lavigne et al. 2011). 

Lavigne H, Epitalon, JM, Gattuso JP, 2011. Seacarb: seawater carbonate chemistry with R.
R package version 3.0. http://CRAN.R-project.org/package=seacarb

BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- combined data from the 8 submitted trial files

Benthic macroalgae contribute to intensely productive near shore ecosystems and little is known about the potential effects of ocean acidification on non-calcifying macroalgae. Kübler and Dudgeon will test hypotheses about two macroalgae, Ulva spp. and Plocamium cartilagineum, which, for different reasons, are hypothesized to be more productive and undergo ecological expansions under predicted changes in ocean chemistry. They have designed laboratory culture-based experiments to quantify the scope for response to ocean acidification in Plocamium, which relies solely on diffusive uptake of CO2, and populations of Ulva spp., which have an inducible concentrating mechanism (CCM). The investigators will culture these algae in media equilibrated at 8 different pCO2 levels ranging from 380 to 940 ppm to address three key hypotheses. The first is that macroalgae (such as Plocamium cartilagineum) that are not able to acquire inorganic carbon in changed form will benefit, in terms of photosynthetic and growth rates, from ocean acidification. There is little existing data to support this common assumption. The second hypothesis is that enhanced growth of Ulva sp. under OA will result from the energetic savings from down regulating the CCM, rather than from enhanced photosynthesis per se. Their approach will detect existing genetic variation for adaptive plasticity. The third key hypothesis to be addressed in short-term culture experiments is that there will be a significant interaction between ocean acidification and nitrogen limited growth of Ulva spp., which are indicator species of eutrophication. Kübler and Dudgeon will be able to quantify the individual effects of ocean acidification and nitrogenous nutrient addition on Ulva spp. and also, the synergistic effects, which will inevitably apply in many highly productive, shallow coastal areas. The three hypotheses being addressed have been broadly identified as urgent needs in our growing understanding of the impacts of ocean acidification.

NSF Climate Research Investment (CRI) activities that were initiated in 2010 are now included under Science, Engineering and Education for Sustainability NSF-Wide Investment (SEES). SEES is a portfolio of activities that highlights NSF's unique role in helping society address the challenge(s) of achieving sustainability. Detailed information about the SEES program is available from NSF (https://www.nsf.gov/funding/pgm_summ.jsp?pims_id=504707).

In recognition of the need for basic research concerning the nature, extent and impact of ocean acidification on oceanic environments in the past, present and future, the goal of the SEES: OA program is to understand (a) the chemistry and physical chemistry of ocean acidification; (b) how ocean acidification interacts with processes at the organismal level; and (c) how the earth system history informs our understanding of the effects of ocean acidification on the present day and future ocean.

Solicitations issued under this program:
NSF 10-530, FY 2010-FY2011
NSF 12-500, FY 2012
NSF 12-600, FY 2013
NSF 13-586, FY 2014
NSF 13-586 was the final solicitation that will be released for this program.

PI Meetings:
1st U.S. Ocean Acidification PI Meeting(March 22-24, 2011, Woods Hole, MA)
2nd U.S. Ocean Acidification PI Meeting(Sept. 18-20, 2013, Washington, DC)
3rd U.S. Ocean Acidification PI Meeting (June 9-11, 2015, Woods Hole, MA – Tentative)

NSF media releases for the Ocean Acidification Program:

Press Release 10-186 NSF Awards Grants to Study Effects of Ocean Acidification

Discovery Blue Mussels "Hang On" Along Rocky Shores: For How Long?

Discovery nsf.gov - National Science Foundation (NSF) Discoveries - Trouble in Paradise: Ocean Acidification This Way Comes - US National Science Foundation (NSF)

Press Release 12-179 nsf.gov - National Science Foundation (NSF) News - Ocean Acidification: Finding New Answers Through National Science Foundation Research Grants - US National Science Foundation (NSF)

Press Release 13-102 World Oceans Month Brings Mixed News for Oysters

Press Release 13-108 nsf.gov - National Science Foundation (NSF) News - Natural Underwater Springs Show How Coral Reefs Respond to Ocean Acidification - US National Science Foundation (NSF)

Press Release 13-148 Ocean acidification: Making new discoveries through National Science Foundation research grants

Press Release 13-148 - Video nsf.gov - News - Video - NSF Ocean Sciences Division Director David Conover answers questions about ocean acidification. - US National Science Foundation (NSF)

Press Release 14-010 nsf.gov - National Science Foundation (NSF) News - Palau's coral reefs surprisingly resistant to ocean acidification - US National Science Foundation (NSF)

Press Release 14-116 nsf.gov - National Science Foundation (NSF) News - Ocean Acidification: NSF awards $11.4 million in new grants to study effects on marine ecosystems - US National Science Foundation (NSF)