Ocean Acidification Inquiry
Department of Ocean & Earth Science
A response from the University of Southampton | January 2017
A response from the University of Southampton | January 2017
1. SUMMARY OF MAIN POINTS:
1.1 Three long–term ocean chemistry datasets from the waters surrounding Bermuda provide critical data to understand the processes and impacts of ocean acidification. These datasets constitute the longest record of ocean acidification on the planet. They show a substantial reduction in pH of 15% over the past thirty years due to the absorption of carbon dioxide (CO2) from the atmosphere with implications for coral reefs and other important marine ecosystems.
1.2 The Bermuda coral reef ocean acidification record highlights the importance of other ocean climate (physics and biology) feedbacks that contemporaneously impact the reduction of ocean pH due to ocean acidification.
1.3 At present, Bermuda coral reefs appear to be an important global refugia for coral species against the impact of ocean acidification.
1.4 There are very few sustained ocean observations of ocean acidification and ocean chemistry changes longer than ten years currently collected on the planet. Seven of the worlds’ longest records of ocean acidification from around the worlds ocean reveals similar rate of pH reduction due to CO2 absorption from the atmosphere.
1.5 Knowledge of the impact of ocean acidification is key to the policy area of fisheries/marine resources and environmental protection. Ocean acidification poses a substantial threat to marine ecosystems, and species, but the speed and nature of the threat (and its geographic variability) are not well understood. Future decision–making in this area, and options for mitigation, prevention and adaptation, should be based on evidence.
1.6 The UK does not at present sufficiently support the long–term monitoring of ocean acidification and ocean chemistry changes in its territorial waters, and has ended the funding cycle for the UK Ocean Acidification (UKOA) project. A coordinated, long–term strategy of scientific funding for monitoring, assessment of impact and response of key marine ecosystem to ocean acidification requires framework research funding for at least the next ten to twenty years.
1.7 In addition, the UK does not at present support the long–term monitoring of ocean acidification and ocean chemistry changes (including monitoring, prevention, mitigation and adaptation) in its UK Overseas Territories (UKOTs) territorial waters whose Exclusive Economic Zone (EEZ) marine waters constitute an area eight times that of UK mainland territorial waters. This is a major gap in knowledge, and also hampers economic development and environmental protection of the UKOTs.
2. BACKGROUND OF THE AUTHOR:
2.1 Nicholas R. Bates, PhD, DSc, is Professor of Ocean Biogeochemistry at the University of Southampton, UK and Director of Research/Senior Scientist at the Bermuda Institute of Ocean Sciences (BIOS), Bermuda. He has worked primarily in the United States federal agency realm of scientific research funding for the past twenty–five years but also in Canada and UK. He has published more than 150 scientific papers, ostensibly on the ocean carbon cycle, climate change, and ocean acidification. He has contributed to the 4th and 5th Intergovernmental Panel on Climate Change (IPCC) assessments, and other United Nations, World Meteorological Organization (WMO), US Environmental Protection Agency (EPA) and World Wildlife Fund (WWF) reports.
3. OCEAN ACIDIFICATION–TERMNIOLOGY AND OVERALL IMPACT:
3.1 The chair comments as preamble to the inquiry serve as a useful introduction to the global issue of ocean acidification, ‘Climate change often overshadows other environmental issues, but it is not the only problem being caused by rising levels of carbon dioxide. CO2 is also being absorbed by the oceans, making our oceans gradually more acidic’. However, it should be noted that ocean acidification does not mean that the oceans are at present acidic or will likely become acidic in the near future. Rather, at present, our oceans are typically slightly alkaline with some exceptions in marine environments such as the continental shelves and open ocean of the Arctic Ocean, in the outflows of slightly acidic rivers to the marine environment.
3.2. Ocean acidification presents another global environmental issue, not directly related to climate change, but results from the impact of rising carbon dioxide (CO2) in the atmosphere and the absorption of this gas by the global ocean. The direct impact of ocean acidification is a change in the chemical environment of the ocean.
3.3 Ocean acidification thus refers to the process of shifting ocean chemistry of marine waters from a slightly alkaline state to a less alkaline state. Ocean acidification does alter the pH of marine waters, reducing pH due to uptake of CO2.
3.4 The absorption of CO2 in seawater alters the chemistry of seawater in a scientifically very well understood manner. As seawater absorbs CO2, the balance of chemical reactions changes with the following effects: 1. pH decreases; 2. There is an increase in the concentration and activity of hydrogen ions that act as an acidic component of seawater; 3. There is a reduction in the concentration of carbonate and bicarbonate chemical forms in seawater. The hydrogen ion concentration and activity of seawater is described scientifically as pH (or the negative logarithm of the hydrogen ion concentration). Importantly, in simple terms, as pH decreases, hydrogen ion concentration increases proportionately [Ref. 1].
3.5 From numerous studies in the scientific literature, the reduction of carbonate and bicarbonate chemical forms in seawater due to ocean acidification has a direct impact on the ability of coral reefs, marine animals such as pteropods and foraminifera, and marine plants such as coccolithophores to produce their hard calcium carbonate (CaCO3) shells or tests, thereby reducing the viability and health of these key marine species and ecosystems [Refs. 2–5].
3.6 The reduction of pH in marine waters due to ocean acidification has both direct and indirect impact on coral reefs and other marine species with indirect effects on other species through ecosystem linkages (food, biochemical processes, changes in chemical state of seawater) [Refs. 2,4].
4. QUESTION 1 (The role of increased CO2 emissions, and any other drivers or feedback mechanisms, on ocean acidification):
4.1 Three long–term ocean chemistry datasets from the waters surrounding Bermuda provide critical data to understand the processes and impacts of ocean acidification [Refs. 6,7].
• Data from Hydrostation S, where ocean observations began in 1955, constitute the world’s sustained record of ocean climate change (e.g., warming, and ocean deoxygenation) [Refs. 8,9].
• The worlds’ longest, sustained shipboard observations of ocean acidification and changes in ocean chemistry collected since 1983 [Ref 6].
• The worlds’ longest, sustained observation of ocean acidification and changes in ocean chemistry in coral reefs, collected since 1995 [Ref 7].
4.2 These data of ocean chemistry off Bermuda reveals an increase in dissolved CO2 concentration by 30% over the past thirty years due to the absorption of CO2 from the atmosphere.
4.3 These data of ocean pH changes off Bermuda reveals a reduction in pH (i.e., an increase of hydrogen ion concentration) by 15% over the past thirty years due to the absorption of CO2 from the atmosphere and change in ocean chemistry as a result. These data provide key evidence of contemporaneous ocean chemistry changes associated with ocean acidification, and the impact on coral reefs (see next section).
4.4 The reduction of pH over the past thirty years has shifted ocean pH to a lower state–conditions that are now outside the range of ocean chemistry variability observed in the 1980s and early 1990s [Ref 6].
4.5 The worlds’ longest, sustained observation of ocean acidification and changes in ocean chemistry in coral reefs has been collected in Bermuda since 1995 [Ref 7].
5. QUESTION 2 (Whether ocean acidification and its impact varies regionally):
5.1 There are very few sustained ocean observations of ocean acidification and ocean chemistry changes longer than ten years on the planet. The most recent review of seven of the worlds’ longest records of ocean acidification reveals similar rate of pH reduction due to CO2 absorption from the atmosphere [Ref 10].This includes ocean time–series from the northern hemisphere (e.g., Bermuda, Hawaii, Iceland in the Icelandic and Irminger Seas, Canary Islands, and Venezuela), and one in the southern Hemisphere (New Zealand). This review represented the most recent synthesis of individual scientific papers and updates in the 2013 IPCC report and other reports [Refs 11,12].
5.2 The review of ocean chemistry changes due to ocean acidification highlighted in section four also shows that some oceans have somewhat slower or quicker rates of pH changes due to interaction with changes in ocean physics and biology. Such information highlights the importance of collecting not only ocean acidification data, but other supporting oceanographic data that allow fuller and comprehensive understanding of the causes of ocean chemistry changes.
5.3 The longest global record of ocean acidification from coral reefs is data collected from Bermuda marine waters since 1995. Of concern is the finding that the rate of pH reduction is about double that of the surrounding North Atlantic Ocean. The coral reefs of Bermuda now experience low pH levels and ocean chemistry states that they have not experienced over the past few hundred years [Ref 13] to many millions of years into the past [Ref 14].
5.4 The Bermuda coral reef ocean acidification record highlights the importance of other ocean climate (physics and biology) feedbacks that contemporaneously impact the reduction of ocean pH due to ocean acidification.
5.5 Many scientific studies of the past decade have documented the decline of coral reefs globally due to ocean acidification. However, in Bermuda, even though pH has declined at rates double that anticipated from the absorption of increasing atmospheric CO2, the Bermuda coral reefs appear to be healthy and calcifying (i.e., producing their framework reef structures of calcium carbonate) at increasing rates in recent times. This finding highlights the marine ecosystem complexity of understanding the impacts of ocean acidification. In Bermuda, coral reefs appears to be feeding at higher rates than in the past due to decadal changes in ocean physics and biology of the North Atlantic Ocean, and consequently, they are, at present and by chance it appears, offsetting the impacts of ocean acidification. At the moment, Bermuda coral reefs appear to be an important global refugia for coral species.
6. QUESTION 5 (The gaps in terms of monitoring, prevention, mitigation, and adaptation):
6.1 The UK does not at present sufficiently support the long–term monitoring of ocean acidification and ocean chemistry changes in its territorial waters.
6.2 Funding for the UK Ocean Acidification (UKOA) project has been terminated and there is now no long–term support for monitoring of ocean acidification and ocean chemistry changes in UK territorial waters. A coordinated, long–term strategy for the monitoring, assessment of impact and response of key marine ecosystem to ocean acidification requires framework research funding for at least the next ten to twenty years.
6.3 The UK also does not at present support the long–term monitoring of ocean acidification and ocean chemistry changes (including monitoring, prevention, mitigation and adaptation) in the territorial waters of the UK Overseas Territories (UKOTs). Given the size and importance of the marine area contained within the Exclusive Economic Zones (EEZ) of the UKOTs (eight times the size of the UK mainland EEZ [Ref 15]), this presents a major gap in evidence. Tacking this might include the participatory role of individual territories, the UK Overseas Territories Conservation Forum and the Foreign and Commonwealth Office (FCO). One option would be to includeand inclusion of ocean acidification/ocean climate change monitoring in marine protected area (MPA) initiatives (e.g., Chagos MPA, Sargasso Sea Alliance and the Hamilton Declaration).
7. QUESTION 6 (The impact of previous UK research work, and the sufficiency of research currently underway):
7.1 The current research funding in the UK for ocean acidification research is inadequate to address many of the questions posed by the committee. As noted earlier, long term monitoring of ocean acidification and the response of key marine ecosystems is needed. The evidence shows that moniroting is needed in different geographical locations.
8. QUESTION 7 (What areas of Government policy-making are currently held back by insufficient knowledge/evidence on ocean acidification, and the risks this pose
8.1 The key area of policy held back by a lack of data are fisheries/marine resources and environmental protection. Ocean acidification poses a substantial threat to marine ecosystems, and species, but the speed and nature of the threat (and its geographic variability) are not well understood. Future decision–making in this area, and options for mitigation, prevention and adaptation, should be based on evidence. MPAs and other marine conservation areas are a key mechanism by which the Government seeks to do this. To be effective, they need to be based not just on the current state of the marine environment and ecosystems, but how they are changing over time–in part as a result of ocean acidification. As already stated, there is insufficient long-term monitoring and scientific impact assessment on marine ecosystem and species at present.
8.2 As well as the UK itself, there is insufficient scientific knowledge (including basic baseline ocean data in addition to ocean acidification and ocean climate change data) in the marine environments of the UKOTs that are at present under the jurisdiction and sovereignty of the UK. These diverse marine, territorial waters of the UK include tropical/subtropical environments including coral reefs, deeper cold water coral reefs, and subpolar/polar waters. Policies based upon extracting value from the marine resources and protecting the environment for the UKOTs, requires long term monitoring of ocean acidification in these different regions.
9. QUESTION 8 (What areas of Government policy-making are currently held back by insufficient knowledge/evidence on ocean acidification, and the risks this pose)
9.1 Typical, fixed term (three to five year) research projects funded by the UK research councils present a barrier to longer–term monitoring, environmental impact assessment and continuity of ocean acidification research in the UK.
9.2 New mechanisms of longer term research funding to support ocean acidification studies (and ocean climate change research that provide context and clarity for scientific understanding of the issue) should be considered as a policy intervention.
9.3 UK policy interventions could also include improved, national, scientific capacity building in ocean acidification and oceanography (training of scientists, technicians, engineers, etc.,) to maintain the UK’s leadership role in global scientific endeavours. National, bilateral coordination of ocean acidification based research and networking should be fostered and encouraged.
9.4 During the past decade, many other countries have increased their support for ocean acidification research. International coordination of ocean acidification based research should be encouraged to maximize complementary effort, and minimization of duplication.
January 2017
REFERENCES AND DATA CITED IN THIS SUBMISSION
[1] Zeebe, R.E., and Wolf-Gladrow, D., 2001. CO2 in seawater: Equilibrium, kinetics, isotopes. Elsevier Oceanography Series.
[2] Royal Society, 2005. Ocean acidification due to increasing atmospheric carbon dioxide. Royal Society policy document, 12/05; 60pp; http:///www.royalsoc.ac.uk
[3] Gattuso- J.–P, and Hansson, L., 2011. Ocean acidification. Oxford University Press, 408 pp.
[4] Gaylord, B., Kroeker, K.J., Sunday, J.M., Anderson, K.M., Barry, J.P., Brown, N.E., Connell, S.D., Dupont, S., Fabricius, K.E., Hall–Spencer, J.M., Klinger, T., Milazzo, M., Munday, P.L., Russell, B.D., Sanford, E., Schreiber, S.J., Thiyagarajan, V., Vaughan, M.L.H., Widdicombe, S., and Harley, C.D.G., 2015. Ocean acidification through the lens of ecological theory. Ecology, 96 (1), 3–15.
[5] Breitburg, D.L., Salisbury, J., Bernhard, J.M., Cai, W.-J., Dupont, S., Doney, S.C., Kroeker, K.J., Levin, L.A., Long, W.C., Milke, L.M., Miller, S.H., Phelan, B., Passow, U., Seibel, B.A., Todgham, A.E., and Tarrant, A.M., 2015. And on top of all that… Coping with ocean acidification in the midst of many stressors. Oceanography, 28(2), 48–61, http://dx.doi.org/10.5670/oceanog.2015.31.
[6] Bates, N.R., Best, M.H., Neely, K., Garley, R., Dickson, A.G., and Johnson, R.J., 2012. Indicators of anthropogenic carbon dioxide uptake and ocean acidification in the North Atlantic Ocean. Biogeosciences, 9, 2509–2522, doi: 10.10.5194/bg–9–2509–2012.
[7] Bates, N.R., 2017. Twenty years of marine carbon cycle observations at Devils Hole Bermuda provide insights into seasonal hypoxia, coral reef calcification and ocean acidification. Frontiers in Marine Science (in press).
[8] Hydrostation S data; http://www.bios.edu/research/projects/hydrostation-s/.
[9] Bermuda Atlantic Time-series Study (BATS) data; http://www.bios.edu/research/projects/bats/.
[10] Bates, N.R., Astor, Y.M., Church, M.J., Currie, K., Dore, J.E., Gonzalez–Davila, M., Lorenzoni, L., Muller–Karger, F.E., Olafsson, J., and Santana–Casiano, J.M., 2014. Changing ocean chemistry: A time–series view of ocean uptake of anthropogenic CO2 and ocean acidification. Oceanography, 27(1), 121–141.
[11] Intergovernmental Panel on Climate Change (IPCC), Fifth Assessment Report, 2013; https://www.ipcc.ch/report/ar5./
[12] U.S. Environmental Protection Agency, 2016. Climate change indicators in the United States, 2016, Fourth Edition. EPA 430-R-16-004; https://www.epa.gov/climate-indicators.
[13] Goodkin, N.F., Wang, B.-S., You, C.-F., Hughen, K.A., Grumet–Prouty, N., Bates, N.R., and Doney, S.C., 2015. Ocean circulation and biogeochemistry moderate interannual and decadal surface water pH changes in the Sargasso Sea. Geophysical Research Letters, 42, 4931–4939, doi:10.1002/2015GL064431.
[14] Caldeira, K. and Wickett, M.F., 2003. Anthropogenic carbon and ocean pH. Nature, 425, p. 365.
[15] Sea Around Us; Fisheries, Ecosystems and Diversity; http://www.seaaroundus.org/.