Oceans at high risk of unprecedented Marine extinction scientists warn

A report issued last week from the International Programme on the State of the Ocean (IPSO) has strongly warned of the damage to the health of the world's oceans and marine life from several factors including the impacts of climate change. The report warned that if the current business as usual trajectory of damage continues "that the world's ocean is at high risk of entering a phase of extinction of marine species unprecedented in human history."

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The predominant three factors damaging the ocean are associated with human caused climate change: ocean warming, ocean acidification and anoxia (oxygen depleted dead zones). The three primary factors have been important factors in previous mass extinctions on the earth that have occurred in the past 100 million years. Added to these are the stressors of overfishing and pollution which undermine ocean resilience creating negative feedback of accelerating damage to marine ecosystems.

The impacts of climate change on the ocean have been documented since the 1970s, and if anything are accelerating.

The report comes out of a workshop convened of world experts on the ocean that met between 11-13 April 2011 at the University of Oxford. The Workshop was led by International Programme on the State of the Ocean (IPSO) in partnership with the International Union for the Conservation of Nature (IUCN).

Ove Hoegh-Guldberg , Director, Global Change Institute, University of Queensland outlined in Case study 2 (PDF) that coral reefs are facing major stress from overfishing and polution and now ocean warming and acidification.

“It is very clear from the workshop that we are seeing an unprecedented rate of change in the world's oceans. This is being generated by climate change, populatio pressure and an increasing extraction of limited resources such as fisheries. The impacts on the ocean are becoming extremely serious. If we continue on our current pathway, many of the ecosystem services which humans depend on will disappear with extremely dire outcomes for people in every country of our planet. These changes will take thousands of years to reverse.“ Professor Hoegh­‐Guldberg said at the conclusion of his case study.

Key scientific points from the workshop included:

  • Human actions have resulted in warming and acidification of the oceans and are now causing increased hypoxia.
  • The speds of many negative changes to the ocean are near to or are tracking the worst-case scenarios from IPCC and other predictions. Some are as predicted, but many are faster than anticipated, and many are still accelerating.
  • The magnitude of the cumulative impacts on the ocean is greater than previously understood
  • Timelines for action are shrinking
  • Resilience of the ocean to climate change impacts is severely compromised by the other stressors from human activities, including fisheries, pollution and habitat destruction.
  • Ecosystem collapse is occurring as a result of both current and emerging stressors
  • The extinction threat to marine species is rapidly increasing.

The workshop participants also suggested the following recommendations to both citizens and governments to undertake to change how humans manage, govern and protect the ocean:

  • Immediate reduction in CO2 emissions along with better management of coastal and marine carbon sinks
  • Urgent actions to restore the structure and functon of marine ecosystems in both national waters and the high seas by:
    • reduce fishing to a sustainable level;
    • close unsustainable fisheries;
    • establish globally comprehensive marine protected areas to conserve biodiversity;
    • prevent, reduce and control toxic substances and nutrients into the marine environment;
    • avoid, reduce or stringently regulate oil, gas and mineral extraction
    • assess, monitor and control other uses of the marine environment through spatial planning and comprehensive impact assessment, such as on underwater cable and pipelines, marine based renewable energy.
  • Proper and universal implementation of the precautionary principle
  • Urgent introduction by the UN Security Council and the UN General Assemby of effective governance of the High Seas. The workshop put forward detailed proposals for a new Global Ocea Compliance Commission.

In several video explanations and case studies the scientists outline the dire state of the world's oceans, the rapid rate of change and impacts on the ocean and marine ecosystems.

Professor Charles Sheppard, Warwick University gives further perspective to the extinction threat facing coral reefs — and stresses that the knock-on effects are already being felt on land. He points out that about a third of reefs have died, and another third are in imminent danger of following suit. Coral reefs are being tipped beyond their resilience with acidification, ocean warming, pollution and overfishing.

Professor Jelle Bijma, Marine Biogeosciences, Alfred Wegener Institute for Polar and Marine Research. Watch his explanation, beginning with the growing problem of anoxia, or dead zones, in the ocean.

Chemical pollution in the oceans is now impacting marine life, reducing their resilience argues Professor Tom Hutchinson, Centre for Environment, Fisheries & Aquaculture Science (CEFAS). Read his Case Study 3 (PDF) on Pollution and Marine Species: new challenges of an old problem.

Overfishing is examined in Case Study 4 (PDF) by Dr William Cheung, Lecturer in Marine Ecosystem Services, School of Environmental Sciences at the University of East Anglia. Up to 63% of assessed fish stocks are over-exploited or depleted according to a recent study, with over half requiring reductions in fishing for stocks to recover. He warns that the extinction threat for many species is increasing due to the multiple pressures on marine life. Reducing fishing is one way to build some species resilience to combat the multiple threats of pollution, climate change, habitat destruction and invasive species.

The speed of change is far greater than most scientists prediced even in worst case scenarios argues Professor Chris Reid, Marine Institute, University of Plymouth and Sir Alister Hardy Foundation for Ocean Science.

Watch the video presentations embedded at the IPSO website - Multiple ocean stresses threaten "globally significant" marine extinction

Background and Further Information:
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