Table of Contents

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

Literature review of Ocean Acidification (OA) effects on phytoplankton, focusing on growth rate effects.

Details of literature review are contained in Dutkiewicz et al. 2015 (10.1038/NCLIMATE2722). Any use or re-analysis of this data should cite this paper.

Compilation of Acidification Experiments
(modified from supplemental material associated with Dutkiewicz et al., submitted 2015)

In order to develop a baseline understanding of the responses of phytoplankton groups to ocean acidification, we conducted a comprehensive literature search of laboratory studies (current as of December 2014). We focused on growth rate effects, but additional data were recorded as well. A search of the Web of Science was conducted using the search phrase "(coccolith* OR diatom* OR prochloroc* OR synechoc* OR trichodes* OR crocosphae* OR diazotroph*) AND (CO₂ OR "carbon dioxide" OR "ocean acidification") AND ("growth rate")". Each abstract was read and any paper that mentioned a comparison between ambient and elevated CO₂ conditions was downloaded. Additional papers were selected based on reference lists from the above papers and personal communications with researchers. We further curated these papers by excluding any that i) did not actually compare growth rates at different CO₂ concentrations, ii) did not specify the CO₂ levels examined, iii) used CO₂ concentrations outside the range 250 – 1100 ppmv, iv) attempted to separately manipulate CO₂ concentration and pH using organic buffers, v) manipulated CO₂/pH in such a way as to radically change alkalinity, and/or vi) presented data in such a way that it was impossible to calculate a ratio of elevated:ambient growth rates. One additional paper was removed because it had been retracted. We also did not consider comparisons of growth rates for organisms in mixed communities or for freshwater species.

Table 1 (PDF) shows the papers that were used for the meta-analysis, and Table 2 (PDF)shows the papers that were rejected along with the reasons for rejection. Values were collected from tabulated data in papers where possible; otherwise values were estimated visually from figures. No attempt was made to extract information about replication level, variance, or significance level of data; only experimental means were collected. Many papers examined the response to CO₂ enrichment under a variety of environmental conditions (e.g., different light or nutrient levels). Each environment was considered as a unique experiment, and no attempt was made to examine covariance or synergy between any other parameter and response to CO₂.

All data points in the dataset represent ratios of the value in a high CO₂ experiment to the value in an ambient CO₂ environment.

BCO-DMO Processing Notes:
- Replaced spaces with underscores in the reference, organism, and class columns.
- Removed commas and parentheses from the reference column.
- Replaced commas with semi-colons throughout the dataset.
- Replaced blanks 'nd', meaning 'no data'.
- Modified parameter names to conform with BCO-DMO naming conventions.
- Created new column, 'measurement_type', and sorted data accordingly.

Version history:
Version 2 (current): published 2015-07-07 (spreadsheet submitted by J.J. Morris on 0215-07-03; significant changes made in the organization of data, including the creation of separate columns for different CO₂ conditions). Version 2 is available from the "Get Data" button on this page.

Version 1: published 2015-03-26 (spreadsheet submitted by J.J. Morris on 19 March 2015). Version 1 is attached as a Supplemental File (OA_Lit_Review_03262015.csv)

Note: This project is also affiliated with the NSF BEACON Center for the Study of Evolution in Action.

Project Description from NSF Award:
Human activities are driving up atmospheric carbon dioxide concentrations at an unprecedented rate, perturbing the ocean's carbonate buffering system, lowering oceanic pH, and changing the concentration and composition of dissolved inorganic carbon. Recent studies have shown that this ocean acidification has many short-term effects on phytoplankton, including changes in carbon fixation among others. These physiological changes could have profound effects on phytoplankton metabolism and community structure, with concomitant effects on Earth's carbon cycle and, hence, global climate. However, extrapolation of present understanding to the field are complicated by the possibility that natural populations might evolve in response to their changing environments, leading to different outcomes than those predicted from short-term studies. Indeed, evolution experiments demonstrate that microbes are often able to rapidly adapt to changes in the environment, and that beneficial mutations are capable of sweeping large populations on time scales relevant to predictions of environmental dynamics in the coming decades. This project addresses two major areas of uncertainty for phytoplankton populations with the following questions:
1) What adaptive mutations to elevated CO2 are easily accessible to extant species, how often do they arise, and how large are their effects on fitness?
2) How will physical and ecological interactions affect the expansion of those mutations into standing populations?

This study will address these questions by coupling experimental evolution with computational modeling of ocean biogeochemical cycles. First, cultured unicellular phytoplankton, representative of major functional groups (e.g. cyanobacteria, diatoms, coccolithophores), will be evolved under simulated year 2100 CO2 concentrations. From these experiments, estimates will be made of a) the rate of beneficial mutations, b) the magnitude of fitness gains conferred by these mutations, and c) secondary phenotypes (i.e., trade-offs) associated with these mutations, assayed using both physiological and genetic approaches. Second, an existing numerical model of the global ocean system will be modified to a) simulate the effects of changing atmospheric CO2 concentrations on ocean chemistry, and b) allow the introduction of CO2-specific adaptive mutants into the extant populations of virtual phytoplankton. The model will be used to explore the ecological and biogeochemical impacts of beneficial mutations in realistic environmental situations (e.g. resource availability, predation, etc.). Initially, the model will be applied to idealized sensitivity studies; then, as experimental results become available, the implications of the specific beneficial mutations observed in our experiments will be explored.

This interdisciplinary study will provide novel, transformative understanding of the extent to which evolutionary processes influence phytoplankton diversity, physiological ecology, and carbon cycling in the near-future ocean. One of many important outcomes will be the development and testing of nearly-neutral genetic markers useful for competition studies in major phytoplankton functional groups, which has applications well beyond the current proposal.

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)