Marine agriculture
Shrimp: My favorite food and why I no longer eat them
I grew up on the Texas coast, and remember going to meet the shrimp boats at the docks. We’d lug home an ice chest full of the tasty little critters, which my mom would behead and pack in containers that went into the deep freeze in our garage. We enjoyed shrimp meals year ‘round.
In my adult years, trips to the coast with my own family always ended with a stop at a roadside truck to buy four or five pounds of shrimp to take home.
But a few years ago, I gave up shrimp.
Shrimp boats plying bay or Gulf waters are surrounded by clouds of gulls and pelicans in a scene reminiscent of The Birds. The birds are there because, for every pound of shrimp pulled up in the nets, roughly four pounds of other marine life dies, according to Mark Fisher, science director of the Texas Parks & Wildlife Department Coastal Fisheries division. (The amount varies from season to season and year to year, he adds.) That unwanted bycatch — juvenile fish, rays, sharks, crabs, sea turtles — goes over the side, often dead or dying. Great news for the scavengers, not so great news for the marine ecosystem.
Imagine if buying a six-pound chicken meant that up to 24 pounds of sparrows, finches, cardinals, blue jays, and woodpeckers also ended up dead. I think many of us would think twice about buying that chicken.
Freshwater prawns remain a niche market, with once-a-year harvest, and aren’t generally available in retail outlets. They can purchased directly from farms.
In the first six months of 2011, more than 400 sea turtles washed up on the Louisiana, Mississippi and Alabama coasts. Scientists conducted necropsies on 78 of them and found evidence of drowning as well as fish in the guts of most. Sea turtles don’t normally drown, unless they’re caught in fishing gear. Nor do they typically eat fish, although they will scavenge dead fish, such as bycatch from trawling operations. The evidence indicates that these turtles died following close encounters with shrimp trawls.
In fact, federal fisheries regulators estimated that trawling for shrimp in the Gulf in 2009 killed 5,365 sea turtles. (Clink on link to the NMFS data table.) Since the US government began requiring shrimp trawlers to have Turtle Excluder Devices (TEDs), that allow turtles to swim out the bottom of the nets, sea turtle deaths attributed to trawling have decreased. But there are some problems with enforcing proper use of TEDs, and the state of Louisiana even forbids such enforcement, according to the Sea Turtle Restoration Network.
Shrimp boats in the Gulf use bottom trawls: Large, open-mouthed nets pulled behind the boat very close to the sea floor, sometimes for hours. A large chain drags the bottom, where shrimp hang out, causing them to jump up so the net can catch them. Unfortunately, that dragging chain and net destroy the mudflats along the sea floor, which provide habitat for a wide variety of critters. Some have called bottom trawling akin to bulldozing the rainforest to harvest coconuts.
Okay, you say, but my shrimp come from farms. There are a few environmentally friendly, sustainable farms, but most farmed shrimp come from countries with little regulation.
These farms are, understandably, located along the coast. This has meant the removal of many miles of mangroves, which provide vital habitat for baby fish and other marine life, a sheltered place they can hide out and eat from nutrient rich waters until they’re big enough to swim in open water.
Mangrove roots trap sediments and actually build shoreline. They also provide protection from storms and hurricanes. Removing them, then, reduces the health of the entire marine ecosystem, contributes to shoreline erosion, and leaves communities vulnerable to more damage from storm surges.
Shrimp farms also contribute to water pollution through the concentration of feed and the byproduct of all that feed (read: feces). To prevent disease outbreaks, shrimp farmers often use antibiotics, contributing to a growing problem of antibiotic resistance in humans.
According to a study at Oregon State University, it takes one ton of carbon dioxide to produce a one-pound bag of frozen shrimp from a typical Asian farm — the result of poor land use (clearing the mangroves), inefficiency (five square miles of land producing 2.2 pounds of shrimp), and soil contamination.
Still can’t give up shrimp? Monterey Bay Aquarium’s Seafood Watch program recommends freshwater prawns from US farms as the best choice. According to Seafood Watch, most farms in the US are located inland, and so are not destroying important coastal habitat. Freshwater prawns, or Malaysian prawns, are territorial and cannibalistic and don’t tolerate crowded ponds.
Omnivores, the prawns eat insects and plants that naturally occur in their ponds and so don’t need a lot of added feed. Freshwater prawns remain a niche market, with once-a-year harvest, and aren’t generally available in retail outlets. They can purchased directly from farms. Wise County Shrimp Farm near Decatur, for example, sells its harvest on-site in late September. (Road trip!)
The restaurant and retail food industries generally respond to consumer demand, so tell your favorite places that you’d like to see US-farmed freshwater prawns on the menu and shelf. With enough demand, freshwater prawns could become more widely available, out-compete imports from foreign, unsustainable farms and keep the sea pristine for all creatures.