Essentially the Winter Skate resembles a pancake with a short tail and it has a very flattened, depressed body and a slender tail. It possesses a disc about 1.3 times as broad as it is long and a snout with an anterior angle of about 130 degrees. The mouth is gently arched with 63 or more rows of teeth in the upper jaw. The Winter Skate can attain a maximum size of 109 cm total length. Usually the Winter Skate is found living over sand or gravel bottoms, usually in depths less than 111 meters. One Winter Skate was captured at a depth of 371 meters in the Gulf of St. Lawrence. Winter Skate eat mostly amphipods and polychaete worms although they also consume fishes, decapods, isopods and bivalves. Fishes, such as the sand lance, are of greater importance in the diet of large individuals.
Skates produce egg cases and the female Winter Skate produces 35 eggs per year. Winter Skate from the Gulf of Maine have a partially defined reproductive cycle with a peak in reproductive activity in July and maximum egg case production in September, October and November. Male skates produce sperm throughout the year and reproductively capable females are found during most months of the year. Young Winter Skates are 11.2 to 12.7 cm long when they emerge from the case.
Winter Skates are slow-growing, late-maturing and long-lived and therefore vulnerable to decline due to overfishing. That is to say delayed age at maturity, long generation time, low fecundity and consequently slow population growth make the Winter Skate a prime candidate to be decimated by overfishing. Usually Winter Skate mature at between 70 cm and 109 cm. According to the Bedford Institute of Oceanography out of the four most commonly occurring species of skate on the Scotia Shelf, Winter Skate has the lowest intrinsic rate of population growth and thus can sustain only very low levels of fishing pressure. At present there is no fishery for the Winter Skate but it is still taken as by-catch by trawlers. Trawling is the principal commercial fishing method used to target skates but they are also taken as by-catch in gillnets and longlines. They are also taken as by-catch in groundfish and shrimp trawls and scallop dredges. The total allowable catch for Winter Skate for the Scotian Shelf was reduced from 2000 tons in 1994 to 200 tons in 2003. There are has been a 98 percent reduction in the abundance of Winter Skate in the southern Gulf of St. Lawrence and a 90 percent reduction in the abundance of Winter Skate for the eastern Scotian Shelf. No recovery of these populations is expected even if target and by-catches are held to zero.
The probable cause for the decimation of Winter Skate populations is the unsustainable rate at which they were captured as by-catch in fisheries directed at other demersal species. The populations of Winter Skates for the western Scotian Shelf, the Bay of Fundy and Georges Bank remain stable. There are low concentrations of Winter Skate in the coastal waters of Newfoundland and the Grand Banks.
photo courtesy of DFO