PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
The roughhead grenadier belongs to the family Macrouridae, which as a group are often referred to as rattails. It is distinguished from similar species in the North Atlantic by its fairly broad head exhibiting ridges with scute-like scales bearing strong spinules that provide it with its common name. In this report, roughhead grenadier are treated as a single designatable unit in Atlantic Canada (including the Flemish Cap and other waters beyond the 200-mile limit).
This species is widespread on the upper continental slope and deep continental shelf throughout the North Atlantic. Females mature at 13-15 years with a generation time of approximately 20 years. The species is distributed from Davis Strait in the north to Georges Bank in the south, occurring both inside and outside 200 n. miles, primarily in depths between 400 and 1500 m. Research vessel surveys have not consistently covered deep portions of the range and catch a low proportion (ca. 2%) of mature adults. Canadian survey index decline rates over 15 years (< one generation) of > 90% occurred in the 1980s and early 1990s, but the surveys only covered depths to 1000 m. This decline is probably due to a combination of distributional change and abundance decline: there is evidence for movement of fish into deeper water as a result of the cooling of the shelf in the 1980s, and reduction in population size due to fishing pressure is also a possible factor. The species is caught primarily as bycatch in the Greenland halibut fishery, which has experienced reduced Total Allowable Catch and greater restrictions on areas of operation since 2000. However there are no catch limits or management plans for the species in Canadian waters, and catch reporting of foreign vessels is often unreliable. Survey indices (Canadian and European Union) for adults have been stable over the past decade. The species is of concern because of late maturation, lack of evidence of return of adults to shallower depths with return to environmental conditions prevailing prior to the 1980s, a probable decline in abundance in the 1980s and 1990s, and the lack of a management plan for directed and incidental harvest.
Canada’s Species at Risk Act (SARA) provides legal protection for wildlife species at risk to conserve biological diversity. It also acknowledges that all Canadians have a role to play in the conservation of wildlife species.
Before deciding whether Roughhead Grenadier (Macrourus berglax) will be added to the List of Wildlife Species at Risk, we would like to hear your opinion, comments, and suggestions regarding the possible ecological, cultural, and economic impacts of listing or not listing this species under the SARA.