Aquaculture

The problems and unanswered questions pertaining to aquaculture and its ecological impacts are numerous. Confining fish in unnatural densities creates significant fecal and feed-pellet pollution underneath sea cages and allows diseases to transfer more readily among captive fish and into wild populations. Farmed fish escapes occur regularly and create such pressures on wild populations as increased competition for habitat and mates. The captive breeding of non-native species, such as Atlantic salmon on the West Coast and rainbow trout on the East Coast, has resulted in escaped fish surviving and reproducing in the wild.

DFO

The Department of Fisheries and Oceans has been criticized for failing to uphold its mandate — to protect fish and fish habitat — in its quest to develop aquaculture. Consequently, business decisions have been made without adequate knowledge of the marine environment or the impacts of aquaculture.

Still many unknowns

There are still many unknowns when it comes to aquaculture. For example, the impact of sea lice from fish farms on wild salmon stocks. A recent article in the journal Nature studied this particular issue on the coast of British Columbia and concluded that wild juvenile pink salmon close to fish farms did experience an increase in mortality due to sea lice infestations. However, DFO reports that while they are studying this issue they have never seen evidence that sea lice is a problem for wild populations.

More focus is currently being applied to closed-containment systems. Closed-containment systems would reduce the interactions between farmed fish and the aquatic environment, thereby reducing many of the concerns associated with open-net aquaculture such as sea lice, pollution and escapes. However, up to now, closed-containment systems have not been feasible, either technologically or economically. More research is being performed in this area to determine if the challenges associated with such a system can be overcome.

CWF’s position

CWF’s position on aquaculture is simple — increase scientific research and dramatically raise the environmental standards of these operations or shut them down.

CWF continues to research and follow this issue. CWF is dedicated to protecting wild fish populations and their habitat, to secure their survival not only us but for future generations.