> Environmental and Health Concerns > Biodiversity

Fish is a healthy source of protein and omega-3s, and eating the right fish just twice a week may help protect against heart disease, improve immune function, alleviate depression, and reduce arthritis symptoms.

Many of us have heeded the advice to eat more fish. More than 100 tons of fish are consumed worldwide each year, and demand for seafood is expected to increase 1.5 percent annually.

While fish may be good for our health, we’ve exceeded the ocean’s capacity to meet our demand for seafood, and that’s not good for us. The quantities of fish we’re pulling from the oceans–whether for human consumption, to feed farmed fish, or as bycatch (incidentally caught and wasted fish)–are not sustainable.

One Fish, Two Fish, Less Fish, No Fish

The UN Food and Agriculture Organization (FAO) reports that 52 percent of the world’s fish stocks are currently fully exploited (harvested at maximum capacity); 24 percent are overexploited (caught at a rate higher than they can reproduce), are already depleted, or recovering from depletion.

In other words, three-quarters of the world’s fish are in danger of disappearing. According to the World Wildlife Fund, seven of the top 10 ocean fisheries are currently either fully or overexploited.

A 2003 report published in Nature concluded that, after 50 years of heavily industrialized fishing practices, just 10 percent of all large fish are left. The rate at which fisheries have collapsed has accelerated, and this trend may “project the global collapse” of all species currently fished by 2048.

But the report’s authors don’t see their projections as pronouncements of unavoidable doom: they conclude that current trends are reversible.

Net Worth

At present, oversized fleets taking in unsustainable catches are often government-subsidized, while illegal, unregulated, and unreported catches meet with poor enforcement. Dredging (raking the seafloor), bottom trawling (dragging a net on the seafloor), and longlining (fishing with a central line up to 50 miles (80 km) long, strung with smaller lines of bated hooks), kill millions of fish unintentionally. The FAO estimates that 7.3 tons of fish are annually discarded as bycatch.

The clear solutions include well-managed fisheries&where the health of the ecosystem, not just a single fish stock, is considered&sustainable catch limits, controls on bycatch, and the establishment of protected marine wilderness areas. Catch share programs (a.k.a. Limited Access Privilege Programs or LAPPs) offer economic incentives to maintain the health of the ocean’s natural resources, and where already implemented have resulted in reduced bycatch, increased safety and revenues, better protection of habitat, and improved compliance for catch limits.

Farmed and Dangerous

If fishing wild stocks is destroying the ocean, isn’t aquaculture (fish farming) the best solution? It depends.

The environmental impact of fish farming is tied to the type of fish that’s farmed, how it’s farmed, and where the farm is located. Many farmed fish are raised in crowded open-net pens where their waste pollutes the water below; antibiotics and other drugs given to farmed fish can leak directly into the ocean; and diseases may spread from farmed to wild fish. Farmed fish can and do escape, where they compete with already depleted stocks of wild fish for diminishing resources. If carnivorous fish (such as salmon) are farm raised, they must consume wild fish: it takes about 3 lb. (1.4 kg) of wild fish to produce 1 lb. (0.5 kg) of farmed salmon.

Inland aquaculture may provide a healthier habitat than open nets; enclosed, recirculating systems, where some shrimp, tilapia, catfish, and trout are currently raised, keep fish, wastes, and drugs away from sensitive coastal habitats. Catfish and tilapia, in addition, are plant-eating fish that don’t depend on wild fish for food.

Seafood Afishionado

Governments, industry, and consumers can all play a role in improving the health of our oceans. The David Suzuki Foundation recently suggested that the Canadian government should commit $600 million over five years to improve Canada’s performance on ocean conservation.

“The condition of Canada’s oceans is getting worse and Canada is falling behind other developed nations, like Australia and New Zealand, in protecting its oceans,” says Bill Wareham, acting director of marine conservation. “Canada is definitely headed in the wrong direction. We’re degrading natural habitat, increasing pollution, and failing to provide the necessary planning for and protection of ocean and coastal environments.”

Our seafood purchases can help make a difference. Buy seafood that’s harvested or raised sustainably. When making purchases, ask:

1. Where is the seafood from?
2. Is it farmed or wild?
3. How was it caught?

Download a copy of Canada’s Seafood Guide to determine what types of fish make good health and environmental choices.

Ninel Guthrie is a freelance writer who will be asking more questions at her favourite sushi restaurants.

Source: alive #300, October 2007