Prawn/shrimp - making sustainable choices

August 6th, 2010

Updated August 6th, 2010

Love prawn cocktail? Crispy shrimp tempura? Jambalaya? Prawn, once considered a height of luxury, is now available everywhere and it’s affordable. Americans consume an average of 4 pounds of prawn/shrimp per person annually and the US is the largest prawn importing nation in the world (Japan is the second). But what’s the real cost of our great appetite for prawn to the ocean and to the environment?

Maybe it’s worth considering how that prawn got to the dinner plate. Most of the prawn we consume is either caught by trawling or is farmed.

Trawling for prawn

Trawling is an extremely destructive form of fishing. This method involves a fishing net shaped in a cone being dragged on the bottom of the ocean. It is indiscriminate in what it takes from the sea bed and for every pound of prawn, 20 pounds of bycatch result. The Environmental Justice Fund estimates that trawling kills 150,000 turtles each year.

Prawn fishing is energy intensive. Producing a kilogram of trawled, de-shelled prawn uses ten times more energy than producing the same weight of clams.

So we can forget trawled prawn but is farming the way to go?

Prawn farming, mangroves and destruction

To meet the demand for cheaper prawn, thousands of hectares of mangrove forest are being destroyed in South America and Asia to make way for prawn farms. Mangroves are coastal swamps that soak up CO2 from the atmosphere and protect against climate change. They play a crucial role in protecting coastal areas from erosion, storm damage and flooding. Also significant, fewer mangroves also mean fewer fish as 85% of all commercially-fished species depend on mangroves as nurseries in the tropics.

Thai prawn – cheap but not cheerful

Thailand is the world’s largest exporter of prawn. But this growth has not come without negative social, economic and environmental costs. Traditional farmers along the coastal areas were forced to change their crops and practices due to the high demand for shrimp from overseas markets. This has resulted in great disruption of lives and economies. Those who rely the most on the land and water have benefited little from the boom in prawn farming.

The effects of prawn/shrimp farming on the environment

Waste and pollution is a serious problem with prawn farming. The practice requires a great deal of water. Dirty water goes into the surrounding natural environment and this wastewater often contains salt, antibiotics and fertilisers. The overuse and misuse of fertiliser has in some regions, resulted in an explosion of plankton that use up the precious oxygen needed by prawn AND other marine life. Nearly a quarter of Thai shrimp farms were abandoned within few years of starting because the soil had lost its fertility and rendered unusable for other purposes.

The sustainable seafood guides in Canada, US and the UK all RED LIST imported Tiger Prawns and advise against consuming them.

With everything considered, farmed prawn isn’t a good option.

Sustainable prawn choices

We still love the little tasty morsels. The good news is, there are sustainable alternatives. Refer to your local sustainable seafood guides.

Generally, coldwater prawn/shrimp from Arctic oceans around Norway, Iceland, Denmark and Canada would be best choices.In Canada, Spot Prawn from British Columbia are on the green list in the SeaChoice seafood guide. This species is wild and is trap-caught – so are not farmed or trawled.

The better/more sustainable prawns will be more expensive than the mass-produced and trawled ones but that is the case with most sustainable and greener foods.

The sustainable prawn is also healthier as they are not exposed to chemicals and pollutions like farmed shrimp.

It doesn’t look like our great love of prawn is going to end soon but by being a bit more inquisitive and doing our research, we can make much better choices.

Seafood sustainability guides

SeaChoice Seafood Guide (Canada)

Seafood Watch from the Monterey Bay Aquarium (US)

Marine Conservation Society information (UK)

Seafood listing guides from World Wildlife Fund (Europe)

The 3-step Pocket Guide from the Australian Marine Conservation Society