VANCOUVER - Toxic contaminants from a "notorious" Kyuquot Sound salmon farm are having a lasting, negative effect on the seabed in the farm's vicinity, according to a new provincial government report.
An August 2009 Environment Ministry study estimates that Centre Cove salmon farm will degrade seabed marine life as much as 100 metres from the site of the farm for 15 years dating from the farm's 2004 shutdown.
The report warns that the toxic effects from metals released from the farm, notably zinc and copper, could last significantly longer.
"It is notoriously one of the worst fish farms on the coast," David Suzuki Foundation fisheries biologist John Werring said in an interview, adding that an unspecified number of other salmon farms along the B.C. coast are believed to be causing similar effects - "but we just don't know how many."
Werring said the province is considering regulatory changes that would actually make it easier for farms to discharge waste into the ocean.
Copper is part of an "anti-fouling" agent used to deter growth of algae and barnacles on sea pen nets, while zinc is present in fish food and subsequently defecated.
The report said that while oxygen-deficient organic material, notably fish waste, will eventually be flushed away, "metal toxicity" at Centre Cove is a persistent concern for so-called benthic organisms, including oysters and clams.
The west coast Vancouver Island salmon farm dates back to the 1980s, and was owned and operated by Marine Harvest from 1998 to 2004, when the company shut it down because low ocean-current speeds were not effective in dispersing contaminants escaping from the farm.
Salmon Farms Leave Toxic Legacy
-
Toxic contamination will linger at Island salmon farm site, government finds
By Scott Simpson
The Vancouver Sun - Canada, Aug 25, 2009
Straight to the Source
