The 77-metre long ship, Aqua Tromoy is Mowi’s latest and most expensive investment yet to tackle the problem of sea lice.

“This is the only vessel of its type in North America so it’s a big step forward for us,” said Mowi Canada West Communications Manager Chris Read.

On board, she’s a purposely built myriad of tanks, pipes, filters and huge hoses, a floating bathtub for farmed salmon that will wash them of lice, one of the most criticized parts of farming Atlantic salmon.

“So this vessel has been outfitted with a reverse osmosis system that can produce 6000 m3 of fresh water every day which is pretty substantial,” said the ship’s lead captain Courtlan Thomas.

Freshwater is the key because while it’s harmless to the fish, Mowi says it removes sea lice and other saltwater microbes and parasites that do not tolerate low-salinity water very well.

“Basically we bring the fish onboard through a vacuum pump that’s designed for moving fish and the fish are dewatered from the salt water and then they are transported into the holds which are full of fresh water,” said Thomas.

They stay in the freshwater bath for about 7 hours before being released.

The ship can hold 3000 cubic metres of fresh water, much more than another ship Mowi has used that can only hold 650 cubic metres.

Fine filters then remove parasites from the water before it’s dumped back in the ocean.

“As far as I understand it’s been very successful and whilst this is new for Canada, it’s proven technology elsewhere in the world,” said Read.

Fish farm critics say they should be on land, but that this could be an effective way of dealing with lice.

“I do worry though that one boat with a number of farms spread up and down the coast may not be able to control the lice outbreaks that we’ve seen in recent years,” said Living Oceans Executive Director Karen Wristen.

Dean Stoltz