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Ocean In Critical State from Cumulative Impacts

Posted on 12 October 2013 by John Hartz

This article is a reprint of the press release, Latest Review of Science Reveals Ocean in Critical State From Cumulative Impactsposted by the The International Programme on the State of the Ocean (IPSO) on Oct 3, 2013. [Note: Section headings have been added to improve redability.]


An international panel of marine scientists is demanding urgent remedies to halt ocean degradation based on findings that the rate, speed and impacts of change in the global ocean are greater, faster and more imminent than previously thought.

Cover of 2013 IPSO State of the Ocean Report

Results from the latest International Programme on the State of the Ocean (IPSO)/IUCN review of science on anthropogenic stressors on the ocean go beyond the conclusion reached last week by the UN climate change panel the IPCC that the ocean is absorbing much of the warming and unprecedented levels of carbon dioxide and warn that the cumulative impact of this with other ocean stressors is far graver than previous estimates.

Decreasing oxygen levels in the ocean caused by climate change and nitrogen runoff, combined with other chemical pollution and rampant overfishing are undermining the ability of the ocean to withstand these so-called ‘carbon perturbations’, meaning its role as Earth’s ‘buffer’ is seriously compromised.

Professor Alex Rogers of Somerville College, Oxford, and Scientific Director of IPSO said: “The health of the ocean is spiraling downwards far more rapidly than we had thought. We are seeing greater change, happening faster, and the effects are more imminent than previously anticipated. The situation should be of the gravest concern to everyone since everyone will be affected by changes in the ability of the ocean to support life on Earth.”

The findings, published in the peer review journal Marine Pollution Bulletin, are part of an ongoing assessment process overseen by IPSO, which brings together scientists from a range of marine disciplines. The body’s previous 2011 report, which warned of the threat of ‘globally significant’ extinctions of marine species, received global media attention and has been cited in hearings at the United Nations, US Senate and European Parliament as well as the UK Parliament.

Factors Affecting Ocean Health

Among the latest assessments of factors affecting ocean health, the panel identified the following areas as of greatest cause for concern:

  • De-oxygenation: the evidence is accumulating that the oxygen inventory of the ocean is progressively declining. Predictions for ocean oxygen content suggest a decline of between 1% and 7% by 2100. This is occurring in two ways: the broad trend of decreasing oxygen levels in tropical oceans and areas of the North Pacific over the last 50 years; and the dramatic increase in coastal hypoxia (low oxygen) associated with eutrophication. The former is caused by global warming, the second by increased nutrient runoff from agriculture and sewage. 

• Acidification: If current levels of CO2 release continue we can expect extremely serious consequences for ocean life, and in turn food and coastal protection; at CO2 concentrations of 450-500 ppm (projected in 2030-2050) erosion will exceed calcification in the coral reef building process, resulting in the extinction of some species and decline in biodiversity overall.

Warming: As made clear by the IPCC, the ocean is taking the brunt of warming in the climate system, with direct and well-documented physical and biogeochemical consequences. The impacts which continued warming is projected to have in the decades to 2050 include: reduced seasonal ice zones, including the disappearance of Arctic summer sea ice by ca. 2037; increasing stratification of ocean layers, leading to oxygen depletion; increased venting of the GHG methane from the Arctic seabed (a factor not considered by the IPCC); and increased incidence of anoxic and hypoxic (low oxygen) events.

The ‘deadly trio’ of the above three stressors - acidification, warming and deoxygenation - is seriously effecting how productive and efficient the ocean is, as temperatures, chemistry, surface stratification, nutrient and oxygen supply are all implicated, meaning that many organisms will find themselves in unsuitable environments. These impacts will have cascading consequences for marine biology, including altered food web dynamics and the expansion of pathogens.

• Continued overfishing is serving to further undermine the resilience of ocean systems, and contrary to some claims, despite some improvements largely in developed regions, fisheries anagement is still failing to halt the decline of key species and damage to the ecosystems on which marine life depends. In 2012 the UN FAO determined that 70% of world fish populations are unsustainably exploited, of which 30% have biomass collapsed to less than 10% of unfished levels. A recent global assessment of compliance with Article 7 (fishery management) of the 1995 FAO Code of Conduct for Responsible Fisheries, awarded 60% of countries a “fail” grade, and saw no country identified as being overall “good”.

Urgent Action Needed

As a matter of urgency, the marine scientists say that world governments must:

• Reduce global C02 emissions to limit temperature rise to less than 2C, or below 450 CO2e. Current targets for carbon emission reductions are insufficient in terms of ensuring coral reef survival and other biological effects of acidification, especially as there is a time lag of several decades between atmospheric CO2 and CO2 dissolved in the ocean. Potential knock-on effects of climate change in the ocean, such as methane release from melting permafrost, and coral dieback, mean the consequences for human and ocean life could be even worse than presently calculated.
• Ensure effective implementation of community- and ecosystem-based management, favouring small-scale fisheries. Examples of broad-scale measures include introducing true co-management with resource adjacent communities, eliminating harmful subsidies that drive overcapacity, protection of vulnerable marine ecosystems, banning the most destructive fishing gear,and combating IUU fishing. 

• Build a global infrastructure for high seas governance that is fit-for-purpose. Most importantly, secure a new implementing agreement for the conservation and sustainable use of biodiversity in areas beyond national jurisdiction under the auspices of UNCLOS.

The IUCN’s Professor Dan Laffoley said: “What these latest reports make absolutely
clear is that deferring action will increase costs in the future and lead to even greater,
perhaps irreversible, losses. The UN climate report confirmed that the ocean is
bearing the brunt of human-induced changes to our planet. These findings give us
more cause for alarm – but also a roadmap for action. We must use it. “


The report’s lead authors:

Alex Rogers is Professor of Conservation Biology at the Department of Zoology, University of Oxford and a Fellow of Somerville College. He is a marine biologist with special expertise on deep-sea ecosystems, particularly cold-water coral habitats, seamounts and hydrothermal vents and has recently led scientific expeditions to the Indian and Southern Oceans. He also has a special interest in sustainable use of the oceans and human impacts on marine ecosystem. Alex is also Scientific Director of the International Programme on State of the Ocean, an NGO that is specifically analysing current impacts on marine ecosystems globally (see below). 

Professor Dan Laffoley, IUCN Vice-chair, World Commission on Protected Areas is a key figure at the global scale on marine conservation, and widely recognized for his
leadership on Marine Protected Areas and innovative conservation approaches. For
over 25 years he has been involved in leading marine protection efforts at UK,
European and global scales creating many of the key initiatives and concepts that
underlie our modern approaches to protecting the ocean.

The organisations:

IPSO: The International Programme on the State of the Ocean is a unique consortium of scientists and other Ocean experts, including those from the legal, communications and political arenas, created to identify the current problems affecting the global ocean, project the future outcomes of these problems and develop workable olutions to alter the trajectory of degradation. 

IUCN: The International Union for Conservation of Nature is a global environmental 
network with more than 1,000 government and NGO member organizations, and
almost 11,000 volunteer scientists in more than 160 countries.

The Report:

The findings were published in Marine Pollution Bulletin Volume 74 Issue 2 and
available at and also at

Full list of papers and authors:

Introduction to the special issue: The global state of the ocean; interactions between stresses, impacts and some potential solutions. Synthesis papers from the International Programme on the State of the Ocean 2011 and 2012 workshops

Dan Laffoley, IUCN (International Union for Conservation of Nature)
Alex D. Rogers, Department of Zoology, University of Oxford, UK

Climate change and the oceans – What does the future hold?
Jelle Bijma, Alfred-Wegener Institute for Polar and Marine Research, Bremerhaven,
Hans-O. Pörtner Alfred-Wegener Institute for Polar and Marine Research,
Bremerhaven, Germany
Chris Yesson, Institute of Zoology, Zoological Society of London, UK
Alex D. Rogers, Department of Zoology, University of Oxford, Oxford UK

Climate change impacts on coral reefs: Synergies with local effects,
possibilities for acclimation, and management implications
Mebrahtu Ateweberhan, Department of Life Science, University of Warwick, UK
David A. Feary, School of the Environment, University of Technology, Sydney,
Shashank Keshavmurthy, Biodiversity Research Centre, Academia Sinica, Taipei,
Allen Chen, Biodiversity Research Centre, Academia Sinica, Taipei Taiwan
Michael H. Schleyer, Oceanographic Research Institute, Durban, South Africa
Charles R.C. Sheppard, Department of Life Science, University of Warwick, UK

Evaluating legacy contaminants and emerging chemicals in marine
environments using adverse outcome pathways and biological effects-directed analysis
Thomas H. Hutchinson, Centre for Environment, Fisheries and Aquaculture Science,
Weymouth Laboratory, Dorset, UK
Brett P. Lyons Centre for Environment, Fisheries and Aquaculture Science,
Weymouth Laboratory, Dorset, UK
John E. Thain Centre for Environment, Fisheries and Aquaculture Science,
Weymouth Laboratory, Dorset, UK
Robin J. Law Centre for Environment, Fisheries and Aquaculture Science, Suffolk,

Ocean in peril: Reforming the management of global ocean living resources in areas beyond national jurisdiction
Kristina M. Gjerde, IUCN Global Marine and Polar Program, Massachusetts, USA
Duncan Currie Globelaw, Christchurch, New Zealand
Kateryna Wowk NOAA, Washington, USA
Karen Sack, The Pew Charitable Trusts, Washington, USA

Fisheries: Hope or despair?
Tony J. Pitcher, Fisheries Centre, University of British Columbia, British Columbia,
William W.L. Cheung, Fisheries Centre, University of British Columbia, British
Columbia, Canada

Additional resources:

Interviews with authors and workshop contributors, as well as copies of the
reports are available at

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Comments 1 to 10:

  1. The links for Bijima et al, and Ateberhwan et al lead to the wrong papers.  I have not checked the other links.

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    Moderator Response:

    [JH] Links fixed. Thank you for bringing these glitches to our attention.

  2. Link to "Fisheries: Hope or Despair?" should be changed to:

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    Moderator Response:

    [JH] Link fixed. Thank you for bringing this glitch to our attention.


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  4. The state of the oceans is scary. But why, oh why, do apparently scientific reports keep emphasising the political limit of 2C/450ppm? Where is the current science that says anything up to 1.99C is not too bad, but 2C is terrible? Ditton 450ppm. I read something on realclimate recently which pointed at 1.9C being seen, in the past, as the lower limit of a small range of temperature rises that would consign Arctic sea ice to history. That temperature has surely been superseded by a much lower one. And the oceans are already acidifying faster than for millions of years; I can't see it being OK to limit CO2 to less than 450ppm. The urgency is even greater than this report tries to instill.
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  5. There is an additional threat to our oceans and that is the slowly increasing levels of mercury and other heavy metals. Heavy metals have been locked up (and away) for eons in coal reserves and when coal is burned, they aerosolise. Large amounts eventually settle in our oceans, are absorbed by biota such as algae and eventually make it up the food chain on to your dinner plate. Hence the limits on eating palargic fish such as sword fish no more than once a week. A recent three year study measuring tissue levels of heavy metals in 500 whales found alarmingly high levels. The study surmised that this was directly linked to a fall in whale fertility. and this would likely doom most whale populations within 100 years.

    Yet another reason to leave coal in the ground. Thankfully many countries have excellent plans showing a switch to 100% renewables is entirely possible within 10 years. (See Beyondzeroemmissions). 

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  6. The article is a bit hysterical and becomes misleading as biases are intermingled with facts and hypothesis.

    For example: "Ensure effective implementation of community- and ecosystem-based management, favoring small-scale fisheries." implies that small-scale fisheries can't be/ aren't as destructive as "large scale" fisheries. This is a bias not supported by facts. The US gulf coast shrimp trawlers (small boats) clear cut almost the entire gulf every year and put ten times more phosphorous back into the water column than is contributed by the Mississippi River and all the upstream runoff and sewerage from the central part of the US. This impacts eutrophication and the hypoxic zone formation.

    Concepts like: "Build a global infrastructure for high seas governance that is fit-for-purpose" have to face the observational reality described in Public Choice theory that the behavior of that "global infrastructure" will be in the organizations self-interest. The problem is not "building the infrastructure", but designing such infrastructure in such a way that its organizational and individual self-interest aligns with the interest of the planet and humanity. In setting up such a structure, existing fishing interests will be well represented and they will create governance structures to prevent competition from unrepresented future "innovation" in offshore open ocean aquaculture that would put them out of business. 

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  7. Some interesting back and forth on this issue and lessons for the value of staying within one's boundary of expertise or at least being duly cautious can be followed here:

    Seattle Times series on local threats imposed by ocean acidification

    Respected local meteorology researcher Dr. Cliff Mass weighs in

    Author of Seattle Times piece Craig Welch responds to Dr. Mass

    An authoritative NOAA/Washington State report on the whole affair, "Scientific Summary of Ocean Acidification in Washington State Marine Waters" (pdf, 176 pages)

    Thanks for this article, John. We really do need to be more careful with the ocean and what's in it.

    (I should add that the NOAA/Washington item has includes truly excellent background information on the pH problem)

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  8. TonyW  2C is political and what countries have agreed to stay below under the UNFCCC. And are supposed to sign a legally-binding treaty in 2015 on their cuts to get there. It's a target to aim for. 1.5C is a better target, and some countries are fighting for that.  

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  9. The scariest piece of information to me was published in Nature July 29, 2010. I'm not good at links, but use Google Scholar and search "Boris Worm phytoplankton." His team reported a 40% drop in phytoplankton since 1950. Phytoplankton are crucial to much of life on Earth. They are the foundation of the bountiful marine food web, produce half the world's oxygen and suck up carbon dioxide. Half the world's oxygen! I don't know why that fact alone does not send shudders through the population. It may take a long time before oxygen levels are depleted enough to cause harm, but what then?

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  10. bibasir @9, here is a link to the abstract and paper (pdf).

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