There are three species of wolffish that occur Atlantic Canadian waters: Northern Wolffish (Anarhichas denticulatus), Spotted Wolffish (A. minor), and Atlantic Wolffish (A. lupus). The first two species were designated as “threatened” after assessment by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and were listed on Schedule 1 of Canada’s Species at Risk Act (SARA) in 2001, while Atlantic Wolffish was listed as “special concern”. The primary reasons for listing these wolffish under SARA were: greater than 90 % decline in their abundance over 2-3 generations (1980s-90s); and substantial reductions in the extent of their distributions. They are a very cryptic, demersal (bottom-dwelling) species with little commercial value, however, the largest threats facing wolffish are bycatch in commercial groundfish fisheries and climate change.
Although all three species were listed under SARA over ten years ago, very little is known about their fine-scale behavioural and movement patterns, as these species are characterized by broad geographic and depth distributions, tend to be found at low densities, and appear to live a solitary lifestyle except during spawning season. The body of scientific literature on wolffish in Atlantic Canadian waters is extremely sparse and has almost entirely been focused on coastal NFLD. While the Maritimes region is only inhabited by the Atlantic Wolffish year-round, Northern and Spotted species are infrequently captured off the Scotian Shelf. However, there has been no research conducted in this region on any of the three species or their habitat.
Atlantic Wolffish are present within the Bay of Fundy and are sought after subjects for underwater naturalists and photographers. SCUBA is an effective method to observe them in their natural habitat as well as make observations on their surroundings and any impacts as a result of environmental or other changes.
We are using SCUBA to find wolffish and study their habitat. We will also be tagging them with acoustic tags and sampling them using stable isotopes to understand both their movements and diet. Acoustic tagging will provide complementary information to the SCUBA surveys through location, temperature and pressure data. These data, coupled with an intimate understanding of the surrounding underwater landscape of an individual or pair of Atlantic Wolffish, will provide new insights into the behaviour and movement patters of this species. The tagging data will also provide the ability to determine temperature and depth profiles for this species. Other than commercial fishing activities, climate change is listed as one of the most significant threats to Wolffish populations in the Northwest Atlantic.