Ocean under Siege

For decades fishermen have been saying there’s no future in fishing. Environmentalists have been warning about overfishing and pollution harming the ocean’s delicate ecosystem. But so far the ocean has been able to absorb everything humans have thrown at it.

The summary of a new international report(PDF) says that we may be quickly reaching the limit of what the ocean will tolerate. The International Programme on the State of the Ocean (IPSO) convened the first-ever interdisciplinary meeting of ocean scientists. Their report, which has not been released in full, paints a grave picture of the future of the ocean if something doesn’t change.

The report identified three key stressors to the ocean — overfishing, pollution and climate change. They cause ocean acidification, anoxic areas or oxygen-free marine dead zones and ocean warming which have been associated with mass extinctions in the past.

Many nations are trying to improve their fishing practices so as to not wipe out entire fish species. And pollution standards are changing so that the ocean doesn’t have to take in so much run off that creates dead zones where no fish can live.

It is the third area — climate change — where the scientists unanimously say something needs to be done before an entire oceanic mass extinction begins.

Scientists say we are potentially looking at a mass extinction of marine life, the likes of which haven’t been seen since the dinosaur extinction 65 million years ago.

Chris Reid, Professor as the Marine Institute, University of Plymouth and co-author of the report says, “We are seeing levels of pH inthe oceans now that probably haven’t been experienced for 55 million years.”

The speed at which the ocean is changing is what has scientists concerned. They say that ocean is at high risk of entering a phase of extinction of marine species unprecedented in human history. And that those changes will be evident in 20-50 years, not hundreds of years in the future as previously thought.

IPSO Scientific Director Alex Rogers, who is also a Professor of Conservation Biology at the Department of Zoology, University of Oxford is struck by the rapid changes the ocean is experiencing.

He says coral reef ecosystems will likely be lost by the end of the century. And to him that qualifies as a mass extinction. Marine biologists believe there are about 9 million species of animals and plants associated with coral reefs.

Already scientists are seeing fish move north and south of their regular habitats. The fish in the tropics and at the polar extremes of the ocean have no place to go. So Dr. Rogers predicts there will be a large loss of fish in low and high latitudes just because of temperature change.

“If the ocean goes down. It’s game over.” — Dr. Alex Rogers, Scientific Director of IPSO