Thorny Skate

Consultations on listing under the Species at Risk Act

Information summary and survey for the consultations on adding Thorny Skate to the List of Wildlife Species at Risk as Special Concern – Please provide your input by July 23, 2015

Consultations

Let your opinion be heard

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 Thorny Skate (Amblyraja radiata) 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 SARA.

Adding a species to the List of Wildlife Species at Risk…

The process of listing a species under Canada’s SARA consists of several steps:  it begins with a status assessment by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and ends with a Government of Canada decision on whether or not to add a species to the List of Wildlife Species at Risk.  Public consultations are conducted to gather the opinions of Canadians and are an important step in this process.

Facts about Thorny Skate

Thorny Skate is a flattened fish with a disc-shaped body covered in thorns and a slender tail (Figure 1).

It belongs to the Class Chondrichthyes, which includes all shark and skate species.  Thorny Skate is native to the North Atlantic Ocean, and it is the most widely distributed and abundant skate species. In Canadian waters, it is continuously distributed from Baffin Bay, Davis Strait, Labrador Shelf, Grand Banks, Gulf of St. Lawrence, Scotian Shelf, and Bay of Fundy to Georges Bank (Figure 2), in a wide range of depths. The highest concentrations in these waters are found along the southern Grand Banks off Newfoundland and on the eastern portion of the Scotian Shelf.

Thorny Skate is distinguished from other skates in Canadian waters primarily by a row of 11–19 large thorns on the midline of its back and tail. This skate grows slowly, matures late, and produces only a few surviving hard-shelled egg cases (Mermaid’s purses) each year. Average age at maturity is 11 years, and it lives at least 20–30 years.

Thorny Skate
Figure 1.  Thorny Skate.

Illustration of a Thorny Skate viewed from the side. It is a flattened fish with a disc-shaped body covered in thorns and a slender tail. This species is distinguished from other skates in Canadian waters primarily by a row of 11–19 large thorns on the midline of its back and tail. The upper body colour can be highly variable among individual Thorny Skate (ranging from yellow-edged dark spots on light brown to an almost uniform dark brown). The underside of its body is uniformly white, rarely with a few small, non-symmetrical, darkly pigmented markings.

distribution map
Figure 2. Canadian distribution of Thorny Skate (map was adapted from COSEWIC 2012).

Map depicting the Canadian distribution of Thorny Skate. In Canadian waters, it is continuously distributed from Baffin Bay, Davis Strait, Labrador Shelf, Grand Banks, Gulf of St. Lawrence, Scotian Shelf, and Bay of Fundy to Georges Bank.  This map was adapted from the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) 2012 assessment and status report on the Thorny Skate (Amblyraja radiata) in Canada.

Who assigned the Special Concern status to Thorny Skate?

COSEWIC is an independent committee of experts that assesses which wildlife species are in some danger of disappearing from Canada and assigns a status to these species.  It conducts its assessments based on the best available information including scientific data, local ecological knowledge, and Aboriginal traditional knowledge.  COSEWIC assessed Thorny Skate in Atlantic Canada in May 2012 and designated it as Special Concern.  

Why is Thorny Skate at risk?

COSEWIC concluded that threats to Thorny Skate include directed fishing and bycatch.  These slow-growing, late maturing fish have undergone severe population declines over the southern part of their distribution, including a decrease in the extent of the distribution area.  These declines have continued, despite a reduction in fishing mortality.  In contrast, the abundance of mature individuals in the northern part of their range has been increasing, approaching abundance levels observed at the beginning of DFO research surveys (mid-1970s).  Thus, while this species as a whole does not meet COSEWIC criteria for a Threatened status, declines and a decrease in the extent of the distribution area in the south are cause for concern.

We would like to receive your comments on the potential impacts of adding or not adding Thorny Skate to the List of Wildlife Species at Risk under SARA, designated as Special Concern.

Your comments are important.

Please fill out the survey:  we want to hear from you.

If a species is listed under the Species at Risk Act

If Thorny Skate is listed, given the Special Concern status, the prohibitions of SARA (for example, prohibitions against killing, harming, and capturing) would not apply. However, listing would result in the development of a SARA management plan that will include conservation measures for this species in Canadian waters.

A copy of the 2012 COSEWIC Assessment and Status Report on the Thorny Skate and other information can be found on the SARA Registry.

References

COSEWIC. 2012. COSEWIC assessment and status report on the Thorny Skate Amblyraja radiata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. ix + 75 pp.

 

Thank you for completing this survey.

Species at Risk Program 
Fisheries and Oceans Canada
P.O. Box 5667
St. John’s, NL  A1C 5X1
Fax: (709) 772-5562
E-Mail:
saranl-leptnl@dfo-mpo.gc.ca