Monterey Bay Aquarium Research Institute
The Emerging Science of a
High CO2 / Low pH Ocean


Project Summary

Statement of the problem

We propose to tackle the problem of assessing the future impacts of elevated oceanic CO2 levels (lower pH) on marine ecosystems through a unique combination of field and laboratory studies, and to address the associated policy, economic, and permitting issues. This work will draw on MBARI’s exceptional engineering skills, the institutional investment in ships and vehicles, and the new presence of the MARS cable as a unique experimental resource. The inevitable association of higher CO2 levels with climate change and lower oxygen levels, and the cascade of ocean policy issues arising in the post-climate change world will bring additional complexity that only a team effort can address. We propose to develop systems and methods for small-scale perturbation experiments in the laboratory and at sea to expose marine animals to the conditions that will likely represent the ocean of the late 21st century, to communicate these findings to policy makers, and to make the systems and knowledge we create available to users world-wide. CO2 perturbation experiments for land eco-systems have long been carried out and have revealed important predictors and insights that will influence policy. No equivalent experiments have yet been carried out in the ocean.

Why it is important

The ocean, through its alkalinity established over geologic time, has been recognized as the major sink for atmospheric fossil fuel CO2 for about a century now. Callendar (1938) recognized the ocean as “a giant regulator of carbon dioxide”, and for almost all of the 20th century the “natural” ocean uptake of fossil fuel CO2 was regarded as a great benefit to mankind. But the oceanic CO2 invasion rate today exceeds 1 million tons CO2 per hour; we have already disposed of some 500 billion tons of fossil fuel CO2 in the sea, and ultimately about 85% of all mankind’s atmospheric emissions will reside there. Without the benefit of this massive disposal in the upper ocean of the waste product of mankind's energy use, the world would face an overwhelming atmospheric CO2 problem.

Yet the oceanic uptake blessing comes at a price, and that price may be paid by oceanic ecosystems facing ocean chemistry changes of unprecedented scale in the years ahead (Cicerone et al., 2004). It is now well established that upper ocean pH and CO2 levels could reach values not seen on Earth for perhaps 25 million years. And that this may have consequences for calcification in marine plants and animals, in reproduction and growth, and in combination with lowered O2 levels and oceanic warming cause profound and ill-understood changes in marine ecosystems. Ocean policies now in place for fishing zones, marine sanctuaries etc. reflect thinking of static ecosystems which will no longer be valid in our future world. How to predict the changes of the future and to design policies to cope with these will be a fundamental challenge. While a vast literature on likely changes in the oceans physical circulation and nutrient cycles now exists, the parallel information on effects on higher organisms is rudimentary at best and no adequate field experimental protocols have yet been developed.

Present state of our understanding

The present state of the art is captured in a series of widely circulated reports from key national and international meetings, including those of the 2004 SCOR/IOC Paris meeting (Orr et al., 2005), the 2005 UK Royal Society report on ocean acidification, and the 2006 report of NSF-NOAA-USGS resulting from a St. Petersburg workshop (Kleypas et al., 2006). A significant MBARI/Stanford COS workshop was held in March 2007 to review the state of the art. In addition the International Council for Exploration of the Sea (ICES) has established a new Working Group on this topic (PGB as co-chair) - with the P.I.s of this proposal playing a leading role in this venerable North Atlantic organization in spite of their Pacific address. The recent 21st Pacific Science Congress in Okinawa also held a key session on this topic. From participating in these activities the team member have a very clear picture of the state of the art. In brief there are as yet no well established field perturbation experiments, only a few laboratory studies, and no clear policy directions. Thus we feel sure that the goals set here do significantly advance the state of the art.


Callendar, G.S., (1938). The artificial production of carbon dioxide and its influence on temperature. Quart. J. Roy. Met. Soc., 64: 223-240.

Cicerone, R., J. Orr, P.G. Brewer, P. Haugan, L. Merlivat, T. Ohsumi, S. Pantoja, S., and H.O. Portner (2004). The ocean in a high CO2 world. Eos, 85: 351-353.

Kleypas, J.A., R.A. Feely, V.J. Fabry, C. Langdon, C.L. Sabine, and L.L. Robbins (2006). Impacts of ocean acidification on coral reefs and other marine calcifiers. Report of a Workshop sponsored by NSF, NOAA, and the USGS, 88pp.

Orr, J.C. and 26 others (2005) Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature, 437: 681-686.

Royal Society (2005) Ocean acidification due to increasing atmospheric carbon dioxide, pp. 60.

Questions? Comments? Please contact Edward Peltzer.
Last updated: Feb. 04, 2009