Will we empty the oceans?

Last week, Greenpeace released its semiannual seafood sustainability scorecard, which ranks US supermarket chains based on the impacts their practices have on marine life and how well they communicate these practices to the shopper.

The grades are dispiriting. While the environmental advocacy group noted progress among some stores, the top scorer, Wegmans, received only 6 out of 10. Even though the East Coast chain has worked with scientists and conservationists to develop seafood sourcing standards and has removed from its stores a number of species because of sustainability concerns, Greenpeace found that Wegmans continues to sell 15 species – including grouper, monkfish, and Atlantic salmon – that appear on Greenpeace's Red List of fish that are unavailable from sustainable sources.

Other stores fared much worse on Greenpeace's report card. The national chain Trader Joe's – which generally has a good reputation among greens – scored near the bottom, prompting Greenpeace to attack them in a site called Traitor Joe.

You can check how your local supermarkets have performed on Greenpeace's ranking here.

This is about more than just a few endangered species. After a half century of industrial fishing, a quarter of the world's fish stocks are overfished, and another half are fished to full capacity. One study found that, if current trends continue, the world will completely run out of seafood in 30 years.

It wasn't always like this. Here's how the Monitor's series on overfishing last year kicked off:

Early European explorers to the Americas encountered an astounding abundance of marine life. White beluga whales, now limited to the arctic, swam as far south as Boston Bay. Cod off Newfoundland were so plentiful that fishermen could catch them with nothing more than a weighted basket lowered into the water. As late as the mid-19th century, river herring ran so thick in the eastern United States that wading across certain waterways meant treading on fish. And everywhere sharks were so numerous that, after hauling in their catches, fishers often found them stripped to the bone.

So how did we get from that world, where the oceans teemed with marine life, to the growing aquatic wasteland we see today? The answer: One catch at a time.

Here's where we're supposed to dust off the hoary metaphor about boiling a frog. You know the one: Drop a frog in boiling water, and it jumps out immediately. But if you place it in cold water that you heat gradually, the frog won't perceive the danger and will make no attempt to escape as it is gradually boiled to death.

This, of course, is utter nonsense. Dropping a frog in boiling water will almost certainly kill it, and if you heat the water slowly, the frog will jump out once the temperature gets uncomfortable. Sorry, but amphibians aren't that stupid.

Can the same be said for humans? As Nicholas Kristof pointed out in his New York Times column last week, we modern Homo sapiens are pretty much physically identical to our hunting and gathering forebears who lived some 200,000 years ago. As a result, our minds are highly attuned to Pleistocene-style threats, the saber-toothed cat lurking in the grass, the rival eying your mate, the guy from the neighboring tribe with the big stick. When we perceive these kinds of threats – manifested today in the form of images of militants abroad or "moral values" issues at home, our bodies instinctively gear up into fight-or-flight mode

Not so much for those creeping, incremental threats like overfishing. Even though resource depletion can wipe out a species population just as surely as a terrorist attack, the threat isn't visceral. Unless you have a very vivid imagination, contemplating lifeless oceans won't make your eyes widen or your pulse quicken. You're just not built that way.

But, unlike most other animals, we humans have the capacity to override our evolutionary programming and think far into the future. That's why we save for retirement, get regular exercise, and floss. Doing these things are much harder than living for the moment, but important for our long-term viability.

The alternative is to bury our heads in the sand and hope the problem goes away, an act that – while we're puncturing bogus animal metaphors – even ostriches don't do. Can we be smarter than ostriches?

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