People are still using the oceans like their cave-dwelling ancestors used fields and forests a million years ago. We don't grow much tuna, swordfish, or other saltwater finfish. We're marine hunters and gatherers, collecting what grows wild.
The oceans were left behind in the great agricultural revolution 12,000 ago, in which hunters and gatherers began growing their own food. Fertilizers, new seed varieties, and other technology boosted crop yields far beyond what Mother Nature could have provided.
Without farming, humans would have defoliated the landscape in an attempt to feed themselves, and there never would have been food enough for civilization to blossom.
Recent studies have raised similar warning flags for the oceans, including last week's report from the Pew Oceans Commission.
Organizers recruited not just scientists for the three-year project, the most comprehensive United States study in 30 years. It drew on other talent critical for translating recommendations into action. Former California Congressman and White House Chief of Staff Leon Panetta chaired the 18-member panel, which included members from the conservation, commercial, fishing, business, and political communities.
The conclusions in a nutshell: Over-fishing at sea, over-development along the coasts, and increasing pollution from cities and farms threaten fish populations and the entire marine ecosystem. Unless addressed with a national commitment to protect and restore the oceans, those threats could eventually mean loss of commercial fish populations and other problems.
People living inland have almost as big a stake as the 50 percent of the world's population that lives within 60 miles of the coasts.
Covering 140 million square miles, 72 per cent of Earth's surface, the oceans and their interplay with the atmosphere determine global climate, local weather, and even the quality of the air that people everywhere breathe. And, of course, they're the source of healthful seafood that's so much in demand.
United Nations and other studies have documented the stress thus placed on edible fish populations. By 2010, worldwide demand for seafood will top 110 million tons, but catches will fall short by 40 million tons, one U.N. study warned. Almost 70 per cent of marine fish stocks are over-fished, exploited to the hilt, or being rebuilt under fishing restriction policies.
Aquaculture - fish farming - seems to be one obvious way of easing that stress. Big crops of shrimp and freshwater fish are raised in ponds and other facilities. Marine finfish farming, however, remains in the doldrums.
A national policy of tax incentives and other measures to expand marine aquaculture could also bring more abundant and affordable seafood supplies to inland residents.
Far from calling for that step, however, the Pew Commission instead urged a moratorium on expansion of salmon and other finfish aquaculture until a national policy can be formulated. Aquaculture does have environmental side effects, as the Pew Commission noted. But they are manageable and pale in comparison to the adverse effects of over-fishing.
That recommendation appears misplaced in an otherwise sound report, and almost seemed like a concession to commercial fishing interests, perhaps made to get unanimous agreement among commission members on the entire report.
Regardless, the Pew Commission's study makes clear what we're doing to our seas and why we need to stop - soon.