Offshore Aquaculture
spawning sites, or outcompete them for prey. But Atlantic salmon are lousy colonizers7. The species never became established in the rivers of Washington State or British Columbia, despite repeated, concerted attempts to introduce them there over the decades. Atlantics are Chile’s most abundantly farmed species, but it is only Pacific salmon that have become established in the wild there. And Atlantics haven’t become established in Tasmania, even though they have been farmed there for over thirty years. The potential for escapees to have a significant impact on lo-
There are – reassuringly - no reported cases of
hybridization between Atlantic salmon and Pacific salmon, and the “probability of successful hybridisation … seems remote” 56 »
cal prey organisms is probably also overblown. The only food that the farmed salmon have ever known, all their lives, is for pellets to literally fall from the sky, at regular intervals during the day. Studies suggest that, at most, only 20% of Atlantics turned loose in the North Pacific can learn to catch their own dinner8. And if the ecological impact of 20% of some 180,000 escapees is indeed a
genuine concern, then why is there so little debate about the food web impacts of the 5 billion Pacific salmon smolts9 that are willfully released from hatcheries into the North Pacific for stock enhancement. (These smolts are released into rivers after about a year of being farmed in net pens; though it’s not clear how many of the “wild” Alaskan salmon devotees are aware of that fact.)