October 17, 2022

 

Risk assessment on Cooke Aquaculture's salmon farm expansion in Nova Scotia, Canada, released 

  

 

Canada's Department of Fisheries and Oceans had released its review of Cooke Aquaculture's proposed Atlantic salmon farm expansion at Liverpool Bay, Nova Scotia, highlighting potential impacts on lobster and wild salmon.

 

The risk assessment does not recommend approval or rejection of the expansion that is before provincial regulators awaiting a hearing.

 

Cooke, through its subsidiary Kelly Cove Salmon, wants to increase the size of its existing fish farm at Coffin Island in Liverpool Bay and add two more sites nearby at Mersey Point and Brooklyn.

 

If approved, production from each site would be 660,000 salmon — a 370% increase in the number of farmed fish in the bay, according to the DFO report.

 

The DFO assessed the risks from the use of approved drugs contained in fish feed and pesticide baths, the impact of organic material on the seabed, potential for entanglements, effect on wild salmon and cumulative effect of the increase with other human activities underway in Liverpool Bay.

 

The report noted that Cooke does not use approved pest-control products, including hydrogen peroxide and azamethiphos, in the bay. However, it also noted the company has not had a reported escape since Cooke took over the lease in 2010.

 

The company said there is no issue with sea lice at its current Liverpool Bay site.

 

The report assessed the risk of chemicals regardless of whether they are in use. It found that the seabed up to 3.8 kilometres from a site could be exposed to in-feed drugs from waste, if those drugs were used.

 

Pesticide levels that are toxic to some species may travel up to 4.3 kilometres from the proposed sites, if they are used.

 

Lobster and crab are within exposure zones where fish health-treatment products will be used. Adult lobsters may be exposed to in-feed drugs and harmful concentrations of pesticides in shallower areas around a site.

 

Larval lobster may also be exposed to toxic concentrations of pesticides.

 

Restrictions on the use of azamethiphos, a sea lice treatment, are likely to apply from November to May, when lobster pounds less than one kilometre from the proposed sites are operational.

 

The DFO said low oxygen levels caused by smothering sediment have occurred at the current site. But it added that exposures to waste feed and other smothering material may be transient as the seabed is periodically reset by waves and storms.

 

The addition of more feed and waste products from the increased production of fish, in combination with land and marine pollutants, boating traffic and contaminated sites, "suggests a high potential for cumulative effects on water and sediment quality, particularly impacting benthic habitats and associated species," the report stated.

 

The DFO said the proposed expansion would result in an increase in the proportion of escapees in most rivers within 200 kilometres on either side of bay sites with a resulting increase in the risk of interbreeding with wild salmon. The population of wild Atlantic salmon along the Atlantic coast of Nova Scotia is already in serious trouble.

 

Cooke spokesperson Joel Richardson said the company just received the DFO document and has begun a review.

 

"The items raised by DFO appear to all be already addressed within Kelly Cove Salmon's technical and scientific application document to the Nova Scotia Department of Fisheries and Aquaculture," Richardson said in a statement.

 

He disputed a risk identified by the DFO that "the proposed increase in total leased area may result in lobster being inaccessible to the traditional lobster fishery in Liverpool Bay."

 

Richardson said the inshore lobster fishery and its salmon farms co-exist.

 

"We allow lobster fishers to come into our lease areas to set traps and they have great success in every location where we operate including at our existing Coffin Island farm in Liverpool Bay," he commented.

- CBC