According to Chef Karen Barnaby, the trained eye and pallet can tell a clear difference between farm-raised salmon and wild. Farmed salmon is grayer in color and tends to be more fattening. Wild salmon tends to have a healthier pinkish-red hue (due to its krill consumption) and feels more muscular. Salmon farmers, noticing their farmed salmon's grayish hue, have begun feeding their fish additives to bring their color back closer to their wild brethren.
"Farmers can pick the color they want their fish to be from a Salmofan, something that resembles a collection of paint chips" (Farm-Raised Salmon, www.cbc.ca/consumers/market/files/food/salmon). There is no proof that these additives are harmful, but the popularity growth of cheaper farm-raised salmon has some consumers worried about how this will affect wild salmon.
Current Issues.
The potential problem of torn net pens, which can allow hundreds of thousands of Atlantic salmon to escape, could push the local wild salmon out of their habitat. The consequences of this would mean that fewer Pinks, Coho, and Socki would end up at your local fish counter. Recently, the British Columbia government issued a report measuring the impact of fish farms on the seabeds below. Almost half were found to be dumping unacceptable levels of pollutants into the ocean that could affect not only wild salmon, but prawns and shellfish as well. The industry admits that it is a delicate balancing act, but some debris can actually help the environment. Some companies are trying other methods in order to be responsible and keep environmentalists happy, such as Agrimarine Industries who are building salmon pens on dry land that have sea water constantly pumped into them. Farmers are concerned that new technologies are too expensive and will make their product uncompetitive in the global marketplace.
Another pressing concern with farm-raised salmon is the health issue for consumers.