Harmful algae blooms off the west coast of Vancouver Island
Three Cermaq salmon farms suffer mortalities due to algae blooms
Wednesday, November 20, 2019, 00:20 (GMT + 9)
Three Cermaq farms located along the west coast of Vancouver Island are experiencing mortalities due to harmful algae blooms in the area.
“Three of our farms – Binns Island, Bawden Point and Ross Pass – all located within our Tofino operating area, are experiencing harmful algae blooms which are affecting our fish,” says David Kiemele, Managing Director for Cermaq Canada.
“We are seeing two particular types of algae in these regions – Chaetoceros concavicornis and Chaetoceros convolutes – which are both native to the Pacific Ocean. These particular algae have rigid “spines” that are harmful to fish when they come in contact with gills. Blooms are often associated with low dissolved oxygen events and warm ocean water temperatures and weather changes – all of which we are, or have been experiencing,” he added.
The affected farms – Binns Island and Bawden Point located in Herbert Inlet and the Ross Pass farm, located in Ross Pass at the mouth of Herbert Inlet - have been taking measures to reduce the risk for fish in all three sites.
“In the case of algae, we have a number of tools we can use. The first is to minimize activity on the farm site to help lower any possible stress for our fish. We also stop feeding our fish which helps to keep the fish at deeper depths, below the algae. We are running our upwelling system which helps to pump water from deeper oceans depths into the system, which helps to dilute the algae. In some cases, we can use algae skirting or bubble curtains which help form a physical barrier placed around the perimeter of the farm to a depth of several metres, which helps to prevent the algae from entering the system. In this case, the algae have entered the system, so skirts or bubble curtains would not be effective as the harmful algae was already distributed throughout the water column,” added Kiemele.
Cermaq has earlier provided notice of the recent algae bloom and resulting mortalities to the Ahousaht First Nation, in whose territory these farms are operated. The fish are improving and that the water conditions are improving.
Cermaq Canada is located on the west coast of Canada with up to 300 employees. The company has 25 salmon farm licences and operates four hatchers across northern Vancouver Island.
Photo: Google Stree view
Cermaq also informed that in Chile, during a routine sampling at its seawater site Ensenada Rys located in XII Region, a ISA virus was detected on one of the pens at the site. There has been no signs of disease or elevated mortality.
“There are 680,000 fish just above 1 kg average weight at the site at present. The company will harvest any specific pens that are positive as a preventive measure, even though they show no sign of disease,” said Steven Rafferty, MD of Cermaq Chile.