Salmon farming

Salmon farming

However, the readily available, artificially red salmon flesh on sale in the luxury shops across the western world doesn’t reveal the rampant destruction that this industry causes in regions where the fish are produced. Expanding at a rapid rate, fish farming now accounts for over 30 percent of all fish protein consumed annually in the world. But it is single-handedly responsible for the destruction of countless ecosystems and the fishing communities that rely upon them, in some of the most vulnerable marine environments on the planet.

Salmon farming involves the raising and feeding of vast numbers of fish in small contained net pens. A typical farm may contain up to a dozen pens with anything from ten to 15000 fish in each pen.

Intensive feeding

The feeding requirement of carnivorous farmed fish species such as salmon or tuna undermine the often-repeated myth that industrial fish farming offers a solution to over-fishing. To grow a pound of salmon it is necessary to catch up to five pounds of oily fish species, like herring, sand-eel, sardine and mackerel, to process into fish feed. These fish are literally vacuumed up out of the ocean, upsetting the balance of marine ecosystems.

In British Columbia, Canada and Chile the killer whales, dolphins, seals and sealions that once frequented their territorial estuaries, are now shot, trapped, deprived of food or simply repelled with devices invented by the salmon farmers to protect their stock.

Disease

As with all forms of intensive livestock rearing, the high concentration of salmon in each net also encourages the spread of disease. It is common to regularly dose farmed fish with antibiotics in their food to protect against disease. Ultimately this  leads to the presence of antibiotic-resistant bacteria being found in the sediments under the pens. These bacteria could pose a risk to human consumers as well as to the wider ecosystem in which the nets are placed. The nets are typically located in the fast-flowing waters of estuary heads, so that the toxic faeces, uneaten food pellets, parasitic lice, dead fish, escaped non-native fish as well as chemical and antibiotic residues, are distributed over the whole estuarine ecosystem.

A typical salmon farm of 200 000 fish produces roughly the same amount of faecal matter as a town of 62 000 people. The release of this noxious cocktail into the surrounding waters of salmon farms threatens the very survival of smaller, native salmon species, the predators that rely on them and the future of sustainable fishing practices and communities that rely upon clean and healthy oceans.