Winter Skate Eastern Scotian Shelf - Newfoundland population
Scientific Name: Leucoraja ocellata
Taxonomy Group: Fishes
COSEWIC Range: Atlantic Ocean
COSEWIC Assessment Date and Status Change: May 2015
COSEWIC Status: Endangered
COSEWIC Status Criteria: A2b
COSEWIC Reason for Designation: Abundance of mature individuals is estimated to have declined 98% since the early 1970s, and is now at a historically low level. This population’s range size has varied over this time, having increased until the mid-1980s, with a decrease since then. Overfishing in the 1980s and 1990s, including from directed skate fisheries, may have contributed to declining abundance over that period. The main threats since then have been unsustainably high non-fishing mortality, possibly due to predation by Grey Seals, as well as fishing mortality due to bycatch in fisheries targeting other species.
COSEWIC History of Status Designation: The Eastern Scotian Shelf population of Winter Skate was assessed as Threatened in May 2005, and the Northern Gulf - Newfoundland population was assessed as Data Deficient in May 2005. The COSEWIC Guidelines for Recognizing Designatable Units (2013) were used to revise the population structure for the 2015 assessment, resulting in new designatable units. The new Eastern Scotian Shelf – Newfoundland population is composed of the former Eastern Scotian Shelf population and parts of the former Northern Gulf - Newfoundland population. The remaining subpopulations of the Northern Gulf - Newfoundland population were assigned to the new Gulf of St. Lawrence population. The Eastern Scotian Shelf – Newfoundland population was designated Endangered in May 2015.
SARA Status: No schedule, No Status
Date of Listing (yyyy-mm-dd):
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
The Winter Skate is a benthic (bottom dwelling) marine fish with a flattened body and large wing like fins. One of the largest species of skate in Atlantic Canada, the Winter Skate from the Eastern Scotian Shelf-Newfoundland population mature at considerably larger sizes than those in the Southern Gulf of St. Lawrence. Males are typically 11 years old and as long as 91 cm when they reach maturity, while females tend to be 13 years old but only up to 80 cm long. Females deposit fertilized eggs in rectangular, hard-shelled egg cases (or purses) on the ocean floor. A typical female lays 41 to 56 egg cases per year, and the eggs take 18 to 22 months to hatch. Distinctive features of the Winter Skate include: long slender tail; rounded snout; pale brown to dark brown on top (dorsal); white belly (ventral); black spots and one or more larger white spots near the rear corner of each pectoral fin; some measure more than 110 cm long; and newly hatched skates are 10 to 15 cm long.
Winter Skate are only found in (or are endemic to) the Northwest Atlantic Ocean. The Eastern Scotian Shelf-Newfoundland population is 1 of 3 populations in Atlantic Canada, extending from the eastern shore of Nova Scotia to the south of Newfoundland. This area includes Northwest Atlantic Fisheries Organization (NAFO) divisions 4VW and 3LNOP. Winter Skate on the Scotian Shelf exist in the same areas as the Little Skate. These species are difficult to distinguish from one another when they are less than 36 cm long. Winter Skate has a preference for sandy or gravelly bottoms. They are most often found in waters less than 100 m deep. Some are found in waters as shallow as 24 m and a few are found at depths of as much as 657 m. In Canadian waters, Winter Skate tend to prefer warmer waters and are most commonly found on parts of the Scotian Shelf where temperatures range from 5° to 9°C. They are rarely found at temperatures below 2°C. This population of Winter Skate has declined by an estimated 98% since the 1970s, and its range has contracted. Recent population modelling suggests that this population is still continuing to decline.
Winter Skate has a slow growth rate and matures at a later age, resulting in a long generation time and a low reproductive rate. Given these life history characteristics, the Winter Skate may be highly vulnerable to fishing pressure and other threats and unable to quickly recover. This population of Winter Skate has declined by an estimated 98% since the 1970’s and its range has decreased. Recent population modelling suggests that this population is still continuing to decline. The only known human impact on Winter Skate is fishing mortality. There is no directed fishery for Winter Skate, but it is often caught as bycatch in groundfish, scallop and surf clam fisheries. Currently, the greatest threat to this population of Winter Skate appears to be high levels of natural mortality. The exact causes of this high rate of natural mortality have yet to be determined. Very little is known about predation on Winter Skate, though they appear to be eaten by a variety of species including sharks, other skates and grey seals.
The Eastern Scotian Shelf-Newfoundland population of Winter Skate was assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as endangered in 2015. Fisheries and Oceans Canada is currently undergoing a process to determine whether or not the species should be added to the List of Wildlife Species at Risk as endangered under the Species at Risk Act (SARA).
Provincial and Territorial Protection
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.
4 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
COSEWIC Status Reports
COSEWIC assessment and status report on the Winter Skate Leucoraja ocellata, Gulf of St. Lawrence population, Eastern Scotian Shelf - Newfoundland population and Western Scotian Shelf - Georges Bank population in Canada (2017-10-05)Winter Skate (Leucoraja ocellata Mitchill 1815), also known as the big or eyed skate, can be distinguished from other skate species, with the exception of a co-occurring species, Little Skate (Leucoraja erinacea), by its very round and obtuse snout bearing two opaque patches of cartilage, the presence of three or more rows of thorns on its tail and upper body (disc) from the shoulder region to the origin of the first dorsal fin, round dark spots on its upper disc, and generally one or more eye spots near the rear corner of each pectoral fin. Specimens that lack these spots resemble Little Skate so closely when small (21) on the midline of the tail than do Little Skate.
COSEWIC Annual Reports
COSEWIC Annual Report - 2014-2015 (2015-11-20)Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to "assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species". COSEWIC held two Wildlife Species Assessment Meetings in this reporting year (October, 2014 to September, 2015) from November 23 to November 28, 2014 and from April 27 to May 1, 2015. During the current reporting period, COSEWIC assessed the status or reviewed the classification of 56 wildlife species. The wildlife species assessment results for the 2014-2015 reporting period include the following: Extinct: 0 Extirpated: 1 Endangered: 21 Threatened: 11 Special Concern: 21 Data Deficient: 1 Not at Risk: 1 Total: 56 Of the 56 wildlife species examined, COSEWIC reviewed the classification of 40 that had been previously assessed. The review of classification for 24 of those wildlife species resulted in a confirmation of the same risk status as the previous assessment.