Grilled, poached, fried, barbecued. Any way we cook it, Atlantic salmon is one of our favorite foods. It is rich in Omega 3 oils and B vitamins, and we prize its rosy pink flesh. In the wild this results from of a diet of shrimp, krill and other critters.

But the fish on your plate comes from a fish farm. It was raised in a pen with thousands of other salmon, fed pellets made of fish meal, fish oil and other ingredients, and possibly given antibiotics, pesticides, and pink pigments.

With wild stocks in decline, salmon farms were initially welcomed as a way to reduce fishing pressure, allowing wild populations a chance to bounce back. The expected recovery hasn't happened, however, and scientists and researchers have been left scratching their heads.

Some have suggested that these same farms may be partially to blame, pointing out that aquaculture operations have grown and flourished over the same years that wild salmon stocks in the Bay of Fundy have plummeted. Crowded salmon pens are known to attract seals and other predators, and to be susceptible to diseases and parasites, like sea lice. Once sea lice are attached to a salmon, they slowly graze on its flesh, eating it alive. Although post smolts can tolerate up to ten of them before they die, even a few can weaken the fish, making it more vulnerable to other threats.
Another risk posed to wild salmon by aquaculture, however, may be the escape of farmed fish.

Fish raised for aquaculture are different than wild salmon. They are bred to be docile, to get big fast, and to become sexually mature later than wild fish. It makes sense - they are bred for sale in the market, and for survival in crowded salmon pens, not for survival in the wild. Most farm-fed salmon will die once they are outside the protective environment of their cages.

Wild salmon, on the other hand, are adapted over tens of thousands of years to the conditions of a specific river. They know how to survive, how to jump over particular rapids, how to avoid predators. They are better adapted to the rigours of the wild, and they pass that vigour on to their offspring through their genes.

When farmed salmon escape, however, there are problems. Not only do they compete with wild fish for food and habitat, and transfer disease and parasites; but they can interbreed with wild salmon, transferring their weaker, less adaptable genetic information into future generations and replacing the vigorous, quick-witted wild salmon with fish less suited to survive in the wild. One author has likened it to releasing poodles into the wild and expecting them to behave like wolves.

In the Bay of Fundy over the past two decades, tens of thousands of farmed salmon have escaped from cages into the habitat of wild salmon. Farmed fish now outnumber wild fish by a ratio of 48:1 in the North Atlantic.

It doesn't have to be this way.

Salmon farms can be located on land, with closed pens fed by salt water. This reduces the spread of disease and eliminates escapes of farmed fish. It is more costly to the industry than farming in the sea, however, and it raises an important question for us: are we willing to pay more for salmon raised under more secure environmental conditions?

Progress is being made. Some aquaculture companies are making efforts to better contain farmed salmon and to reduce the number of escapes. Researchers are trying to produce sterile strains of domestic salmon that can't interbreed with wild fish should they manage to escape. Developments like these help to protect wild stocks, but it will take a while before they are put into action. At the moment these measures are voluntary and aquaculture companies are under no obligation to report escapes, or disease.

Perhaps the solution lies ultimately with us - the consumer, and the voter. The development of aquaculture is vitally important to some of our communities - both as a source of food, and as a source of income. But, can we ensure that it doesn't cause the extinction of the wild salmon that naturally live in our rivers? What are we willing to do to protect our local heritage?

PHOTO BY GILLES DAIGLE