New tunicate attacking mussel farms

Ciona intestinalis, a new species of tunicate previously found on P.E.I. only in the Montague River, has spread to the Brudenell and Murray rivers, threatening mussel harvests there.

Various species of tunicate have been plaguing mussel farmers for the last few years. Ciona intestinalis doesn't kill the mussels, but it adds four to five months to their 12-month growth cycle, and it makes harvesting difficult.

"It's making a lot more work, and work a lot harder," fisherman Leonard Young told CBC News Tuesday. "A lot more physical work into it, a lot more manpower hours to get the crop out of the water."

The tunicate has been in the Montague River for several years but fishermen say this year it is worse than ever. The federal Department of Fisheries and Oceans Canada confirms that Ciona intestinalis has spread to new sites in P.E.I. this year.

Researchers are watching its spread, and trying to find ways to control it.

"When you dive in the mussel leases, you can hardly see a mussel," said AaronRamsay, a graduate student at Charlottetown's Atlantic Veterinary College. "It's just the Ciona intestinalis tunicate, completely covering the mussel socks."

Outside of the delayed harvest, the tunicate does not affect the quality of the mussels. They are still safe to eat.

The infestation hasn'taffected prices yet, but the pest is driving up costs, and consumers may see prices rising soon.