The rapid changes evident in global marine ecosystems over the past three decades have been exhaustively researched by scientists and reported widely. They include the depletion or near extinction of fish stocks by overfishing, an alarming slowdown in the growth of calcium carbonate structures such as corals and shells caused by decreases in the pH level of ocean water, rapidly expanding regions of oxygen-depleted water or ”dead zones”, and pollution. All disquieting signs of the impacts of human activity, but not nearly as alarming as the assessment of the cumulative effect of these changes delivered by the International Program on the State of the Ocean this week. IPSO’s Global State of the Ocean Report states the health of the oceans has declined further and faster than science has predicted, and concludes that the world’s oceans are at ”high risk of entering a phase of extinction of marine species unprecedented in human history”.
The supporting evidence for this assertion is that all five mass extinctions of life on Earth going back 500 million years were preceded by many of the same conditions now present in the ocean environment. This assertion, which is based on the fossil record, is certain to be disputed in many quarters, but there is no denying that the rate at which carbon is being absorbed by the oceans is unprecedented in recorded human history. It is certainly happening faster than organisms such as phytoplankton – microscopic algae that form the base of the marine food web – can adapt. The interconnectedness of ocean ecosystems with all life on Earth means that acidification, if it continues at present rates, will have profound consequences for life on Earth.
The cumulative effects of destructive fishing practices, biodiversity loss, pollution and oxygen depletion have been documented in telling detail, and such reports ought to have sounded alarm bells among governments around the world. Unfortunately, most have largely turned a blind eye to the causes of ecosystem degradation. Those corrective measures which have been implemented are often insufficiently policed or regulated.
With the world’s population climbing towards seven billion, and with advances in technology having opened up the world’s deepest and most remote waters to fishing on an industrial scale, it is clear the oceans cannot sustain present levels of exploitation or pollution.
Curbing the current levels of vandalism need not necessarily be expensive or disruptive to food supplies. Provided it was adequately regulated, and of the right variety, acquaculture could be expanded to help reduce the pressure on pelagic fish stocks. However, it would need to be done in tandem with the imposition of strict, legally enforceable quotas and by the expansion of marine sanctuaries or reserves that would allow fish stocks to recover.
Cutting the Gordian knot of ocean acidification and pollution is a more difficult conundrum, and one that is inexplicably linked to limiting greenhouse gas emissions. The good news is that marine ecosystems are surprisingly resilient to setbacks of various kinds. But, as one of the co-authors of the report reminds us, the time remaining in which to successfully grapple with the man-made problems is short.
Obama holds key
This morning’s expected announcement by President Barack Obama that the United States will withdraw up to 30,000 troops from Afghanistan by November next year, is a significant milestone in the longest-running war that America has fought. It fulfills a pledge that Mr Obama gave back in 2009 to begin the transfer of forces out of Afghanistan by July 2011. Mr Obama is expected to point to progress in the country, though it is believed that domestic considerations have influenced his thinking: a majority of Americans believe that troops should be brought home as soon as possible, and this number has increased since Osama bin Laden was killed by US special forces.
In his 2009 speech, Mr Obama said the overarching goal of the US remained to ”disrupt, dismantle and defeat al-Qaeda in Afghanistan and Pakistan, and to prevent its capacity to threaten America and our allies in the future”. Even on the most cautious of assessments, al-Qaeda no longer poses the threat to US interests that it once did.
Mr Obama’s drawdown of troops is also significant for America’s allies in Afghanistan, not least Australia, since it will open the door for discussions on when Australian troops can be pulled out. Canberra Times
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