sea lice

Sea lice “game-changer” ship arrives in British Columbia

Mowi’s $35 million Aqua Tromoy will revolutionise treatment of sea lice in British Columbia’s waters

By SeaWestNews

The largest and most technologically advanced ship to ever serve the Canadian aquaculture industry is now in B.C. waters to revolutionise the treatment of sea lice in farmed salmon.

Mowi Canada West’s Aqua Tromoy, costing about $35 million, will be used to provide environmentally friendly fish health treatments, and for moving fish from site to site.

Aqua Tromoy exemplifies Mowi’s commitment to world leading sustainable practices for salmon aquaculture in British Columbia,” said Mowi Canada West Managing Director Dr. Diane Morrison.

“Having a vessel with triple the capacity to our current largest vessel will be a game-changer for our business.

“This vessel is on the cutting edge of aquaculture technology and is a crucially important tool in our integrated pest management strategy allowing treatment with both freshwater bath and hydrogen peroxide, two sea lice treatment methods encouraged by the Aquaculture Stewardship Council.

Aqua Tromoy dramatically enhances Mowi Canada West’s ability to proactively manage our fish health in an environmentally friendly manner,” said Morrison.

Mowi Canada West (MCW) operates salmon farms and processing plants in British Columbia, Canada, where 600 people work together to raise 45,000 tonnes of sustainable Atlantic salmon each year.

Farm-raised salmon are free of sea lice when they are entered into the ocean, but during the fall adult wild salmon may pass sea lice to farm-raised salmon.

Sea lice are naturally occurring parasites found on many species of marine fish, they pose no risk to humans, but may harm tiny juvenile salmon. Salmon farmers have several ways to reduce or eliminate sea lice on their fish so they are not an additional source of infection during the springtime outmigration of juvenile wild salmon. Management techniques can include medicinal (emamectin benzoate by feed) and non-medicinal (freshwater bath, hydrogen peroxide, water pressure).

A highly-trained crew of nine people will live aboard the vessel with each shift providing 24-hour service for Mowi’s farming operations.

The Aqua Tromoy at a glance

The Aqua Tromoy is a state-of-the art aquaculture vessel. Called a wellboat, it has two large holds that can be filled with water, which are used to move fish from site to site, and to provide environmentally friendly treatments of fish. At triple the capacity of any wellboat in B.C., Aqua Tromoy is the largest and most technologically advanced aquaculture vessel working in Canada.

  • Aqua Tromoy is 77 metres long with a breadth of 15 Metres and is the largest vessel used for aquaculture in Canada.
  • The vessel has three times the hold capacity of the largest wellboat ever used by Mowi Canada West. The holds, or wells, can carry 3,000 m3 of water. This is equal to the daily fresh water use of 13,000 Canadians. The water in the tanks can be completely exchanged in 7.5 minutes.
  • The vessel can create fresh water from sea water, using a reverse osmosis system to generate up to 6,000 m3 of fresh water in 24 hours.
  • Fish are lifted from farm pens and immersed in fresh water baths in the vessel’s holds. Atlantic salmon are not harmed by fresh water immersion, but sea lice and other salt water parasites cannot tolerate fresh water well. They fall off the fish and are captured by the vessel’s filtration system.
  • The vessel has cutting edge on-board water treatment process ability including oxygen generation, carbon dioxide (CO2) stripping, and ozone and UV treatment. Water quality systems measure pH, salinity, temperature, oxygen, and CO2. CO2 strippers continuously remove CO2 from the water, with the ability to treat the hold’s entire 3,000 m3 capacity twice in one hour. Oxygen can be injected into the water when running in closed-circulation mode.
  • Aqua Tromoy is powered by four 1440 kWe diesel generators. The advanced IMO Tier III engines uses urea to reduce nitrogen oxide pollutants in exhaust gases.
  • A crew of nine will live aboard the vessel each shift, providing 24-hour service for Mowi’s farming operations in B.C. There will be 18 jobs associated with Aqua Tromoy.
  • Aqua Tromoy was built in Europe by Arctic Shipping and delivered to DESS Aquaculture Shipping in November, prior to making the six-week voyage to B.C.


Feed starving whales farmed salmon, say scientists

B.C. aquaculture giants pump millions into new technology and sea vessels

Scientists set sail to unlock salmon secrets