The Nature Conservancy logo. Protecting nature. Preserving life.Bill Finch, the director of conservation for The Nature Conservancy in Alabama, is blogging for Cool Green Science about the Gulf of Mexico oil spill and the Conservancy’s efforts in Alabama to protect shellfish reef restoration projects there from the coming slick. Read all his posts.

I guess we can’t be absolutely sure who first had the idea of mixing fresh-picked crabmeat with vinegar, oil, onion and spices and calling it West Indies Salad. But the founder of Bayley’s Restaurant near Alabama’s Fowl River makes the best claim, and Bayley’s was the first place that many on the Gulf Coast enjoyed this famous delicacy.

Crab is harder to find these days, and the spill may be the final blow for many who serve traditional Gulf seafood. Bill Bayley let it be known this weekend that he would shut down his family’s historic restaurant before he had to resort to serving “foreign” catch.

No one seems to salivate at the thought of West Indies Salad made with farm-raised Asian catfish.

At another favorite local seafood shop — with handsome views of one of the Gulf’s most productive estuaries — we stopped by for our ritual Sunday evening meal. No crab. The waitress apologized for the sudden jump in the price of oysters. Their locally harvested white shrimp — a closely guarded Gulf Coast secret, plumper, sweeter, fresher than the frozen Gulf shrimp shipped around the country — was still on the menu. I thought I’d better ask: Turns out the latest batch of “local white shrimp” was pond-raised and frozen for the long flight from Asia.

The Gulf Coast produces 40 percent of the seafood catch in the lower 48. But only 20 percent of the nation’s seafood comes from national waters.

A lot of folks worry we may be too dependent on foreign oil. But isn’t it odd: Even as doctors are touting the benefits of seafood for longer and healthier life, and even as more Americans are demanding it, we’re content that 80 percent of our seafood harvest now comes from foreign countries.

The decline in the availability of fresh Gulf seafood started long before the oil spill. We’ve been burning that candle at both ends for a while, harvesting more and more from the ocean, even as we wreck, fill in and generally ignore the health of the marshes, oyster reefs and other habitats that produce the harvest.

Now, we’re almost entirely dependent on marshes, reefs and fishermen in distant seas over whom we have no control, on shores we could not make more productive if we wanted to.

There’s no evidence the overseas harvest will hold up any better than ours has, and we’ve about run out of new oceans we can strip bare. You might remind your doctor of that next time he promises you’ll live 10 years longer if you’ll just eat more seafood.

I don’t know that the Gulf could ever completely satisfy the nation’s growing appetite for seafood. But there’s little doubt that these waters were once far more productive than they are now. Louisiana alone is losing 30 square miles of marsh each year, and has been doing so for decades. How many fish, shrimp and crab disappear each year with the loss of so much of their nursery habitat?

Globally, the acreage of oyster reefs has declined about 85 percent, and only two small oyster harvest areas in eastern North America can claim to have 50 percent or more of their original reefs. One of those, in Mobile Bay, is right in the path of the spill.

It’s not clear what has happened, over the past year or so, to the Gulf Coast blue crabs that once made Bayley’s West Indies Salad such a treat. Maybe the local harvest was on the road to recovery, but the tiny, big-eyed baby crabs that will supply the harvest for years to come are now floating in the Gulf in a chocolate mousse of spilled oil.

For a long time, Gulf Coast blue crabs helped Chesapeake Bay restaurants guard a dirty little secret: The Chesapeake crab harvests had crashed from overharvest, pollution and habitat loss. Maryland’s famous crab cakes were made with Gulf Coast crab meat. I hate to think what Maryland will stuff its famous crab cakes with if the Gulf crab harvest meets the same fate.

The spill will further erode our ability to deliver fresh American seafood to American tables. It may already be too late to halt the immediate impacts. But the long-term security of our nation’s food supply requires that we pay a lot more attention to what’s coming out of our coastal marshes and reefs, and much more attention to what’s going into them.

— Text by Bill Finch, Cool Green Science Blog