Leaping Sea Lice Jump Onto Researchers' Radar

Those pesky little lice that have caused so much tension among the worldwide salmon community are back in the news again, this time because of their apparent acrobatic skill.

A new study that has been published in the peer-reviewed science journal Biology Letters shows a new way sea lice can be transmitted among salmon stocks. Simon Fraser University Doctoral candidate Brendan Connors and researchers from the University of Alberta conducted a study on small pink salmon infected with sea lice that were eaten by predatory cutthroat trout and coho salmon. Their findings show that in approximately 70 per cent of the trials, sea lice from the small pink salmon also infected the predators, and represents the first case in documented literature of lice moving up the food web from a prey to predator species.

"Sea lice on pinks that are about to be eaten by a coho or cutthroat literally do a back flip off the fish they were on and land right between the eyes of the predator," said Connors, a behavioral ecologist. "We were surprised by how often it happened."

Connors also found in his study that sometimes when sea lice were eaten on a pink salmon, they would actually crawl from the mouth of the predator fish through the gills and survive, further evidence of their ability to find ways onto a new host. It's still not entirely clear to researchers just how lice are able to sense the impending doom of their current host, but Executive Director of Watershed Watch Salmon Society, Dr. Craig Orr says it's certainly the male lice that are extremely mobile and able to 'jump ship' very readily.

Read the full article in the Prince Rupert Daily News.