Oceans Under Greater Threat From Climate Change than Previously Believed

The world's oceans are under greater threat than previously believed, according to the latest report issued by the International Program on the State of the Ocean (IPSO) and the International Union for Conservation of Nature (IUCN).

The findings, published in the journal Marine Pollution Bulletin, pointed to acidification, warming and declining oxygen levels as the "deadly trio" that together are affecting the ocean's productivity and efficiency. Should they continue unchecked, the researchers warn of "cascading consequences for marine biology," including changes in the food web and spread of pathogens.

"The health of the ocean is spiraling downwards far more rapidly than we had thought," Alex Rogers, the scientific director of IPSO, said in a statement. "We are seeing greater change, happening faster, and the effects are more imminent than previously anticipated."

Humans, too, face increased risk as decreasing oxygen levels, chemical pollution and overfishing continue to inhibit the oceans' ability to act as a carbon buffer for the environment.

The IPSO/IUCN report comes on the heels of the Intergovernmental Panel on Climate Change (IPCC) analysis, which attributes the ocean with taking the brunt of global warming. As a result, researchers predict the complete disappearance of Arctic sea ice by 2037, increased venting of the greenhouse gas methane from the Arctic seabed and increased incidences of anoxic and hypoxic (low oxygen) events, among other things, in coming decades.

Continued overfishing, meanwhile, "is serving to further undermine the resilience of ocean systems," scientists warn. In 2012, the UN Food and Agriculture Organization (FAO) reported that 70 percent of world fish populations are unsustainably exploited. According to the researchers, 60 percent of countries were recently given a failing grade based on the 1993 FAO Code of Conduct for Responsible Fisheries; no country was identified as being "good."

Current targets for reducing carbon emissions are insufficient to preserve the ocean's integrity, the report warns, pointing to a temperature rise of less than 2 degrees Celsius as vital, for instance, to ensure coral reef survival. In addition, the report argues that the implementation of broad scale measures designed to promote sustainable fishing is urgently needed, including the protection of vulnerable ecosystems and the banning of the most destructive fishing gear.

Finally, a global infrastructure for "high seas governance" is needed, most important of which would be an agreement granting the power and responsibility of "conservation and sustainable use of biodiversity in areas beyond national jurisdiction under the auspices of UNCLOS."

"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," Dan Laffoley of the IUCN said. "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. "