After the Conviction: Dalhousie Researchers Helped Identify Endangered Fish

Dr. Paul Bentzen, a Dalhousie Biologist and his graduate student, Megan McCusker are regional experts on the endangered wolffish. (Abriel Photo)

The country was abuzz with news of the Nova Scotia man who was the first person charged and convicted under Ottawa´s "Species at Risk" law last week. When an East Jeddore fisherman pleaded guilty July 15 to possessing seven northern wolffish, a threatened species, his $3000 fine was earmarked for the Dalhousie program that helped identify the fish. Last February, two Fisheries officers seized the wolffish from the fisherman during an inspection of his boat. The fish had been gutted and their heads were removed which made identification difficult. The Department of Fisheries and Oceans turned to Dr. Paul Bentzen, a Dalhousie Biologist and his graduate student, Megan McCusker to identify the fish. McCusker is pursuing her PhD studying wolffish and was able to identify the fish through DNA analysis.

"We were ideally positioned to give them an answer on the fish," says Dr. Bentzen. "They brought out the fish, we took out a little tissue from each fish; Megan extracted the DNA, sequenced the right part of it, compared it to our data base and it was unambiguous. They were northern wolffish."

The fine will go toward aiding McCusker´s work which is quickly establishing her as a regional expert on the endangered fish. "The story doesn´t end with the conviction," points out Bentzen. "There is a much larger story of species of fish that face an uncertain future. The work Megan is doing is important to help understand the fish and to lay the groundwork for understanding how to preserve it. It´s entirely appropriate that this fine will go toward the very research that helped seal the case." "It is nice to know that the results will be going back into the work," says McCusker. Not used to the attention the case has brought, she remains focused on the job at hand.

Megan McCusker is pursuing her PhD studying wolffish and was able to identify the fish through DNA analysis. (Abriel Photo)

Her work involves examining genetic variation in three species of wolffishes across their native range in the North Atlantic Ocean. Wolffishes have some unusual features that make them interesting to study from a population genetics perspective. They are thought to form monogamous mating pairs, they exhibit paternal care of young, and they have some of the largest eggs of any marine fish. They form nests on the ocean bottom and their offspring are thought to stay close to the nests in their initial stages. As adults, wolffishes are thought to be fairly sedentary, suggesting that they may have highly distinct populations. Unfortunately, many of these unusual features also make wolffishes particularly vulnerable to fishing mortality and habitat degradation by trawl nets. Due to a combination of extensive habitat degradation and capture as by-catch in other fisheries, wolffishes in the Atlantic Ocean have suffered severe population declines since the 1970s. All three species of wolffishes in the Atlantic are currently listed by the Committee on the Status of Endangered Wildlife in Canada as either "special concern" or "threatened".

Dr. Bentzen notes that wolffish are at a fraction of what they used to be - as much as a 90% reduction for some species. And they are still sought as an attractive catch. "They are quite good eating though they aren´t the most visually attractive fish," he notes. "But then again if you saw some of the other gourmet fishes on the market before they were prepared they wouldn´t look all that appealing either."