The problem with net-pen aquaculture is the methodology, i.e. the “net-pen” structure of the system, not the native vs. non-native aspect.
Open net-pen structures with high density populations pollute our marine environment with excessive fish waste, excessive uneaten fish food, toxicity from deteriorating net-pen structures, pesticide chemicals and antibiotic pharmaceuticals, according to scientific studies.
In the crowded pens, whether stocked with native or non-native fish, hundreds of thousands of them, parasitic sea lice flourish and spread to wild fish, especially deadly to young native smolts that migrate past the pens.
Blood-borne pathogens find an ideal environment to increase and spread and infect wild fish in the surrounding marine environment.
The open net-pen method of fin fish aquaculture cannot be done in an environmentally sound way, according to a Johns Hopkins University report.
The only fin fish aquaculture system that is environmentally responsible and safe is Recirculating Aquaculture System (RAS), which is a closed-containment, land-based system of aquaculture water tanks with efficient non-polluting filtration built into it.
This is the system that should be adopted by parties interested in raising fish.
Our native salmon species are in serious decline, as are the orca that depend on them as a food source, according to media reports.
It is environmentally irresponsible to consider the viability of net-pen aquaculture based on its economic advantages or disadvantages.
Stewardship of the environment is paramount.
James Loran,
Port Angeles