Shrimp are now the most popular seafood in North America. More than lobsters or tuna or even salmon.
Getting shrimp to us has become infamous for all the collateral damage it has created. Shrimp trawlers, trawling for adults in the shallow tropics and sub-tropics of the world, have damaged bottom habitats and tossed out an immense load of unwanted bycatch – both features that should continue to condemn the method to oblivion.
Farming shrimp in coastal tidal ponds creates a whole different suite of equally damaging effects: mangroves are destroyed to make the ponds, and the ponds are moved every few years leaving behind nothing but devastation; pollution and waste are extensive; lethal disease is frequently widespread; salination of the underlying water table occurs; and in some regions people who do the farming or collect the fish for fishmeal may work in close to slave conditions, provoking concerns about human rights and social justice. It’s pretty well all bad.
One species in particular, the Whiteleg Shrimp (Litopanaeus vannamei) has become the species of choice for farms from Mexico and the Caribbean to India, Thailand, Vietnam, China, Indonesia and the Philippines. It is native to the warm Pacific coastal waters of Central America from Sonora Mexico south to Peru, and it grows faster, requires less protein to grow, and is more resistant to disease than other species. Everyone wants it.
In 1990 a modest annual Whiteleg fishery of 90,000 tons existed. Then, as the mangrove farms in Asia embraced the species, the fishery grew huge, reaching 3.2 million tons in 2012, dominating the market.
In 2010, because of the mangrove destruction and the human rights abuses, Greenpeace designated Whiteleg Shrimp a Redlist species. A reasonable conclusion would surely be to say sayonara to the whole sorry mess of shrimp farming and trawling.
But all is not yet lost.
Gradually, ‘intensive’ farming has begun, moving the ponds away from the shores, though still dealing with water supply problems, contamination, and disease. Not great news, but better.
Then, in the past few years, a new method of ‘superintensive’ farming has emerged, and it is very promising. The shrimp are bred and the larvae are grown in hatcheries, and post-larvae are then shipped to inland culture facilities. At their best, these facilities grow the shrimp to market size in a few months in biosecure tanks under controlled temperature conditions, using recirculated sea water, requiring no pesticides or antibiotics.
One of these super-intensive farms near Boston was featured recently in the NY Times, but 22 others are scattered across the US – in Iowa, Minnesota, even one near Las Vegas. This is revolutionary. Suddenly many of the problems associated with trawling or coastal pond culture disappear. No habitat destruction, no pollution, no added chemicals, no abused humans.
There’s sophisticated science to all this of course: selective breeding of Whiteleg adults to produce disease resistant larvae requires great care and patience. The largest breeding companies are now in Florida and Hawaii – the one on Molakai for instance. Comparable facilities in Vietnam and China now do their own selective breeding of Whiteleg for farms, but super-intensive tank culture is still uncommon there.
Meanwhile, the companies that have started tank farming in the US are quite excited. Should they be?
Their main remaining challenge is cost, and mostly they supply high end restaurants. But people in America are increasingly concerned that their food is produced in the least damaging way, agreeing to pay more for it where they need to.
Tank farmed Whiteleg Shrimp has now won the highest rating from Monterrey Bay Aquarium Seafood Watch. So let’s buy this stuff. Let’s insist on shrimp that have been raised in tank farms.
Then the tank farms will flourish and spread, replacing mangrove farms and shrimp trawls. The warm water coastal ecosystems will be far better off, bycatch will be radically reduced, and mangroves will not be destroyed for farming shrimp.