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Award Detail

Doing Business As Name:The University Corporation, Northridge
  • Robert C Carpenter
  • (818) 677-3256
  • Peter J Edmunds
Award Date:09/08/2010
Estimated Total Award Amount: $ 1,992,695
Funds Obligated to Date: $ 2,067,539
  • FY 2011=$24,913
  • FY 2010=$1,992,695
  • FY 2012=$49,931
Start Date:01/01/2011
End Date:12/31/2015
Transaction Type:Grant
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.050
Primary Program Source:040100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:RUI: Ocean Acidification- Category 1- The effects of ocean acidification on the organismic biology and community ecology of corals, calcified algae, and coral reefs
Federal Award ID Number:1041270
DUNS ID:055752331
Parent DUNS ID:055752331
Program Officer:
  • David L. Garrison
  • (703) 292-8582

Awardee Location

Street:18111 Nordhoff Street
Awardee Cong. District:30

Primary Place of Performance

Organization Name:California State University-Northridge
Cong. District:30

Abstract at Time of Award

This project is a 4-y effort focused on the effects of Ocean Acidification (OA) on coral reefs at multiple spatial and functional scales. The project focuses on the corals, calcified algae, and coral reefs of Moorea, French Polynesia, establishes baseline community-wide calcification data for the detection of OA effects on a decadal-scale, and builds on the research context and climate change focus of the Moorea Coral Reef LTER. The project goals will be attained by combining the skills of scientists with expertise in tropical algal ecophysiology and coral ecophysiology and will establish a post-doctoral, graduate, and undergraduate mentoring program to accomplish the field experimentation. The project addresses one of the most significant contemporary issues in marine science (OA), capitalizes on the research commitment of the NSF LTER program, and will help to ensure that the US maintains a pivotal role in the global effort to understand OA. Intellectual Merit. While coral reefs have undergone unprecedented changes in community structure in the past 50 y, they now may be exposed to their gravest threat since the Triassic. This threat is increasing atmospheric CO2, which equilibrates with seawater and causes ocean acidification (OA). In the marine environment, the resulting decline in carbonate saturation state (Omega) makes it energetically less feasible for calcifying taxa to mineralize; this is a major concern for coral reefs. It is possible that the scleractinian architects of reefs will cease to exist as a mineralized taxon within a century, and that calcifying algae will be severely impaired. While there is a rush to understand these effects and make recommendations leading to their mitigation, these efforts are influenced strongly by the notion that the impacts of pCO2 (which causes Omega to change) on calcifying taxa, and the mechanisms that drive them, are well-known. The investigators believe that many of the key processes of mineralization on reefs that are potentially affected by OA are only poorly known and that current knowledge is inadequate to support the scaling of OA effects to the community level. It is vital to measure organismal-scale calcification of key taxa, elucidate the mechanistic bases of these responses, evaluate community scale calcification, and finally, to conduct focused experiments to describe the functional relationships between these scales of mineralization. This project is a hypothesis-driven approach to compare the effects of OA on reef taxa and coral reefs in Moorea. The PIs will utilize microcosms to address the impacts and mechanisms of OA on biological processes, as well as the ecological processes shaping community structure. Additionally, studies of reef-wide metabolism will be used to evaluate the impacts of OA on intact reef ecosystems, to provide a context within which the experimental investigations can be scaled to the real world, and critically, to provide a much needed reference against which future changes can be gauged. Importantly, this proposal addresses several of the high priority recommendations of NSF-sponsored workshops and recent reviews of ocean acidification. Significance and Broader Impacts. The significance of this project lies in the current inability of the scientific community to accurately predict the effects of OA on coral reefs. The broader significance and impact of this research is to blend two approaches, a response of organisms to environmental chemistry versus ecological competition and multiple forcing at both organismal and community scales. The data also will provide a baseline for repeated investigations in the coming decades. In addition to conventional broader impacts including the mentoring of postdocs, graduate students, undergraduates, and technicians, CSUN is designated as an Hispanic-serving institution, which will ensure that the research will reach beyond the traditional demographics dominating scientific disciplines in the US. The labs of the co-PIs are integrated within a framework of K-12 education (including teachers and their students), and a mentoring program that forges interactions among children, university faculty, and graduate students. In the field, the Gump Research Station interacts with the Polynesian community through the At'itia cultural center that provides a locus for educational activities.

Publications Produced as a Result of this Research

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Alldredge, A., Carlson, C., & Carpenter, R. "Sources of Organic Carbon to Coral Reef Flats." Oceanography, v.26, 2013, p.. doi:doi:10.5670/oceanog.2013.52 

Brown, A. L., & Carpenter, R. C. "Water-flow mediated oxygen dynamics within massive Porites-algal turf interactions." Marine Ecology Progress Series, v.490, 2013, p.1-10.

Comeau, S., Carpenter, R. C., & Edmunds, P. J. "Coral reef calcifiers buffer their response to ocean acidification using both bicarbonate and carbonate." Proceedings of the Royal Society B: Biological Sciences, v.280, 2013, p.. doi:doi:10.1098/rspb.2012.2374 

Comeau, S., Carpenter, R. C., & Edmunds, P. J. "Response to coral reef calcification: carbonate, bicarbonate and proton flux under conditions of increasing ocean acidification." Proceedings of the Royal Society B: Biological Sciences, v.280, 2013, p.. doi:doi:10.1098/rspb.2013.1153 

Comeau, S., Edmunds, P. J., Spindel, N. B., & Carpenter, R. C. "The responses of eight coral reef calcifiers to increasing partial pressure of CO2 do not exhibit a tipping point" Limnology and Oceanography, v.58, 2013, p.388?398. doi:doi:10.4319/lo.2013.58.1.0388 

Comeau, S., Carpenter, R. C., & Edmunds, P. J. "Effects of feeding and light intensity on the response of the coral Porites rus to ocean acidification." Marine Biology, v.160, 2013, p.1127. doi:doi:10.1007/s00227-012-2165-5 

Edmunds, P.J., Carpenter, R. C., & Comeau S. "Understanding the threats of ocean acidification to coral reefs." Oceanography, v.26, 2013, p.149.

Wall, C. B., & Edmunds, P. J. "In situ effects of low pH and elevated HCO3- on juvenile massive Porites spp. in Moorea, French Polynesia" The Biological Bulletin, v.225, 2013, p.92-101.

Comeau S., P. J. Edmunds, C. A. Lantz, R. C. Carpenter "Water flow modulates the response of coral reef communities to ocean acidification." Nature Scientific Reports, v.4, 2014, p.. doi:doi: 10.1038/srep06681 

Comeau, S., Carpenter, R. C., & Edmunds, P. J. "Effects of irradiance on the response of the coral Acropora pulchra and the calcifying alga Hydrolithon reinboldii to temperature elevation and ocean acidification." Journal of Experimental Marine Biology and Ecology, v., 2014, p..

Comeau, S., Edmunds, P. J., Spindel, N. B., & Carpenter, R. C. "Diel pCO2 oscillations modulate the response of the coral Acropora hyacinthus to ocean acidification" Marine Ecology Progress Series, v., 2014, p..

Comeau, S., Edmunds, P. J., Spindel, N. B., & Carpenter, R. C. "Fast coral reef calcifiers are more sensitive to ocean acidification in short-term laboratory incubations" Limnology and Oceanography, v., 2014, p..

Edmunds PJ "Is acclimation beneficial to scleractinian corals?" Marine Biology, v., 2014, p.. doi:DOI 10.1007/s00227-014-2438-2 

Comeau S., R. C. Carpenter, C. A. Lantz, P. J. Edmunds "Ocean acidification accelerates dissolution of experimental coral reef communities" Biogeosciences, v., 2015, p..

Edmunds, P.J., R. Steneck, R. Albright, R.C. Carpenter, A.P.Y. Chui, T-Y. Fan, S. Harii, H. Kitano, H. Kurihara, L. Legendre, S. Mitarai, S. Muko, T. Nozawa, J. Padilla-Gamino, N.N. Price, K. Sakai, G. Suzuki, M.J.H.. van Oppen, A. Yarid, R.D. Gates. "Geographic variation in long-term trajectories of change in coral recruitment: a global-to-local perspective." Journal of Freshwater and Marine Biology (CSIRO), v.66, 2015, p.1.

Comeau, S., C. Lantz, P.J. Edmunds, and R.C. Carpenter "Framework of barrier reefs threatened by ocean acidification" Global Change Biology, v., 2015, p..

Evensen, N.R., Edmunds, P.J. and Sakai, K. "Effects of pCO2 on spatial competition between the corals Montipora aequituberculata and Porites lutea" Marine Ecology Progress Series, v., 2015, p..

Project Outcomes Report


This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

This project focused on the effects of ocean acidification (OA) on coral reefs around Moorea, French Polynesia, where the United States operates the Moorea Coral Reef, Long-Term Ecological Research site (  OA describes the acidification of seawater by the dissolution of atmospheric carbon dioxide (pCO2) of human origin, and the changes in seawater chemistry threaten the ability of calcified organism to mineralize.  These threats affect marine organisms throughout the world, but the challenges to tropical coral reefs are acute as the biological engineers of these systems – corals and calcified algae – rely on high rates of mineralization to build massive, wave-resistant structures providing goods and services to countless organisms, including humans.  Together with threats to coral reefs created by rising seawater temperature and local-scale disturbances, some researchers have suggested the future of coral reefs is threatened.  To address these issues, we embarked on a 4-year program to answer four questions: (1) what are the shapes of the relationships between pCO2 and the ability of corals and calcified algae to calcify, (2) how are the shapes of these relationships affected by light and temperature, (3) are the effects of pCO2 on calcification by corals and calcified algae affected by food and nutrients, and (4) how can results from small experiments with individual corals and calcified algae be summed to understand how coral reef ecosystems will change in a more acidic future?


In terms of intellectual merit, we have published > 15 research papers ( and 9 graduate theses in the course of addressing the project goals.  Together, these papers contribute to the field in three important ways.  First, our work has confirmed the magnitude of the threat posed to corals and calcified algae by OA, but we have consistently found that at least a few species are resistant to the extent of OA that is expected to occur on a centurial scale, potentially because they are capable of utilizing bicarbonate to support calcification in the light.  Resistance to OA appears to be an intrinsic feature of these taxa, as we obtained similar results in Hawaii and Okinawa; in contrast, susceptibility to OA is slightly accentuated in fast growing corals and calcified algae.  Together, these results provide a basis to understand which corals and calcified algae are likely to populate reefs of the future (i.e., the “winners”), and which are likely to become rare (i.e., the losers).  Second, for corals and calcified algae that are negatively affected by OA, we have shown that their responses are linear without “tipping points”.  This is an important discovery, for while it shows that OA will depress calcification, the effects are likely predictable and gradual.  Finally, as our experiments matured, we progressed from organism-scale analyses in indoor tanks, to community-scale analyses in large outdoor flumes exposed to natural sunlight and realistic flow speeds.  We created replicas of reef communities in these flumes, and matched the communities to those occurring in the lagoon and at 17 m depth, and incubated them at elevated pCO2.  The results of these experiments underscore the negative effects of OA on calcification of whole reef communities, but they show that the most serious effects will be caused by dissolution of sediments and the reef framework itself. 


In terms of broader outreach, our project has contributed to answering a question of broad societal value: will coral reefs endure in a more acidic future?  Our work suggests that coral reefs will persist on a centurial scale, although the species of corals and algae buildin...

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