Hooded Seal
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Description	The hooded seal (Cystophora cristata), is a large member of the hair seal family. While not the most numerous, it is individually the most prized quarry of the sealer among the North Atlantic ice floes. Adults are large and fierce looking, coloured with large black blotches on a grey background.
Life Cycle	Hooded seals grow rapidly, females reaching sexual maturity and whelping between three and seven years, and mostly at four to five years. Males mature at rather older ages, near 10 years, as typical of polygynous species. Information on age is derived from sectioning the canine teeth, which show very regular layering in both the dentine and thick cementum, and has been confirmed from two tagged females which returned to whelp in the Gulf of st. Lawrence at four and five years of age. Hooded seals, like harp seals, whelp in early spring on the pack ice. Unlike harp seals, which whelp at slightly different dates in different regions according to the onset of spring, hooded seals whelp in the second half of March, wherever they occur, with a peak about March 17. They whelp either in loose concentrations (patches) or in scattered families. The pup, the prized "blueback" of commerce, is a beautiful animal, its hair coat a lustrous blue-black on the back and a creamy white on the belly, and weighs at birth about 20 kg. This coat, unlike the temporary white coat of the newborn harp seal, is the permanent coat of the first year. The hooded seal's foetal hair coat or lanugo is shed before birth. Apparently a loose hair coat shed in utero could interfere with breathing at birth, for it is swallowed by the late foetus and passed into the embryonic sac, so that one finds it on the ice in pellets 3 cm in diameter, about the size of a silver dollar piece.
Anatomy	Males reach about 3 m in length and 400 kg in weight, females about 2.4 m and 270 kg. This sexual dimorphism tells us that we can expect a polygynous animal. One may often in fact find what appears to be a mated pair at the icefields in spring, but also often a female and pup surrounded at a distance by from one to seven males waiting to mate with her. The male has a remarkable proboscis which he alternately inflates with air and allows to collapse, evidently a feature used in display to other males. Additionally an orange-red nasal septum may inflate, balloon-like, out of one or other nostril. The skull is massive with formidable incisors and canines and peg-like post-canine teeth. On the ice, the adults may make short lunges, but are no hazard to a reasonably active person who is careful not to trip as he retreats.
Distribution & Migration	Some tens of thousands of hooded seals whelp off northeastern Newfoundland and southern Labrador, and about a thousand in the Gulf of St. Lawrence. Pups have been tagged in this region, mostly in the Gulf because there is now no sealing there for hooded seals. They have been recaptured from shore fisheries around extreme southwest and off southeast Greenland between March and Agust at ages from one to six years. A moulting patch of hooded seals has long been known to form in July and August on the "Storis" of Denmark Striat which drifts south and west around Kap Farvel. There was a hunt for these seals by ships from Norway until 1961. Besides whelping in the Newfoundland region, hooded seals, again together with harp seals, whelp on the ice around Jan Mayen Island (lat. 710N, 80W). Rather surprisingly, tags put on here have not been picked up from the hunts in south Greenland and Denmark Strait. But tags put on in Denmark Strait have been returned from Newfoundland, which confirms the relationship of these two areas of hooded seal distribution. A third concentration of whelping hooded seals occurs at about 640N on the pack ice in Davis Strait, about midway between Baffin Island and west Greenland. This patch, known to whalers in the 19th century, was rediscovered in 1974 from aerial reconnaissance by Canadian researchers, and has been photographed from the air in order to gain an estimate of numbers (about 10,000 pups.) In March 1984 a major research program was mounted by Canadian and Danish researchers on hooded seals. Aircraft were chartered to census whelping patches of hooded seals in the Gulf, on the Front, and in Davis Strait. Ships equipped with helicopters were chartered to go to Davis Strait and the Front, and land-based helicopter in the Gulf, in order to determine the sequence of whelping in time (in order to interpret the aerial census), to tag hooded seal pups, and in Davis Strait, to collect a sample of adult females to study their age frequency and reproductive rate. For this a special Greenlandic permit was obtained, since the whelping patch in Davis Strait is protected from sealing. Results, now being worked up, will greatly increase our knowledge of hooded seal numbers and biology. Hooded seals show a great tendency to wander. After they leave the pack ice in spring most young animals move north, but animals in their first summer frequently remain in the Gulf or estuary of the St. Lawrence, and may move up river as far as Quebec, Montreal, and even to the locks at Ste. Anne de Bellevue which lead to the Ottawa River. A few individuals wander south, having reached as far as Cape Canaveral, Florida, and in Europe as far south as Portugal. Although hooded seals are much scarcer than harp seals in the Gulf of St. Lawrence, their wandering behaviour is much more pronounced. Taking into account this wandering tencency together with the uniforn whelping season and a lack of evidence of stock discrimination shown from body and skull measurement, one could expect a good deal of mixing between different whelping groups of hooded seals. So far, however, limited tagging has not demonstrated such mixing. The recent large-scale tagging described above will give much better information.
Behavior	Hooded seals live over deep water and dive to considerable depths to feed on the spiny redfish Sebastes marinus, and Greenland halibut Reinhardtius hippoglossoides, as well as squids. This fact explains their scarcity in the Gulf of St. Lawrence, which has only a single deep channel, and absence from the Barents Sea, in both of which areas the shallower-feeding harp seals are common.
The Fishery	Hooded seals supply about half the seal catch (currently about 10,000 animals) to Norwegian and Russian ships at the West Ice, near Jan Mayen Island. They provide about 10 per cent of the catch in terms of pelts (in 1982 12.000 animals) to Canadian and Norwegian ships and Canadian small craft and landsmen at the icefields northeast of Newfoundland. They provide a catch of about 5,500 animals to Greenlanders, mostly in the region between Julianehaab in the southwest and Angmagssalik in the southwest. The catch at the Canadian icefields now mostly consists of pups, the catch of adults being set at 5 per cent, of the total in order to protect the adult females. The Greenlandic catch is mostly of animals aged two to six years. Conservation Since not a great deal has been known about stock size, restrictions on catch have been precautionary. Up to 1960, there was a catch of moulting hooded seals in Denmark Strait in July and August (together with Greenland sharks Somniosus microcephalus, caught for their liver oil). The ending of this hunt by Norway in 1961 removed the damaging twice-a-year hunting on the stocks. A steady rise in catches of hooded seals at South Greenland since this time, under a constant effort by hunters, suggest that the stock whelping at Newfoundland has benefitted. In 1983, a direct census of the Newfoundland whleping stock was attempted, but results were incomplete with at least 5,000 pups counted in two out of three patches. However, during the 1960's, catches of young hooded seals fluctuated greatly from year to year. Subsequent sampling of females after full recruitment (at ages six years and older) allowed comparison of the numerical strength of the year-classes that had been caught at these very different levels. Plotting catch against year-class strength allowed an estimate to be made of the number of pups born, on the assumption that most of the variation in recruitment was due to the catch. The figure obtained for the 1960's was about 33,000 pups. Since 1975, there has been a quota of 15,000 hooded seals at the Newfoundland icefields, reduced to 12,000 in 1982 and 6,000 in 1983. Due to progressive tightening of regulations reducing the take of adult females in recent years, most of this catch is of pups. Full information on catching of hooded seals at the West Ice is not available, but quotas have been reduced in recent years, from 34,500 for Norwegian ships in 1976 to 16,700 young in 1980. The quota for Soviet ships in 1976 was 5,500 hooded seals. In this region also, the permitted catch of adult animals has been reduced to a low percentage of the total. Further knowledge of hooded seal biology has required an international research effort between sealing nations. A meeting to pool existing knowledge was held in Norway in November 1983, and the joint Canadian-Danish research program in March 1984 marked a major step forward in research achieved.

SOURCE: Communications Directorate
Department of Fisheries and Oceans
Ottawa, Ontario
K1A 0E6
© Minister of Supply and Services, Canada
Cat. No.: Fs 41-33/42-1985E
ISBN: 0-662-13647-0