Features
Harp Seal separates into three populations according to their breeding locations: the White Sea, the West Ice and Northwest Atlantic. Seals breeding in the Northwest Atlantic near Newfoundland, Canada represent the largest population and are genetically different from seals breeding in the two other places, which have not been proven genetically different from each other. All three populations are hunted commercially, mainly by Canada, Norway, Russia and Greenland

Population
There are no reliable estimates of the size of Northwest Atlantic population when commercial hunting began in the early 1800s.Several simulation models estimated virginal populations to be in the 3 to 4 million range.It is considered that the population recovered to about 3 million at the end of World War II, but subsequently declined by 50–66% between 1950 and 1970 due to commercial hunting in Canada. Quotas and other conservation measures since then have enabled the population to nearly triple in size to 5.2 million according to a peer-reviewed survey in 1999.

The Northwest population
Mature females usually give birth to one pup in March/April each year. The pups are born within well defined areas in the drift ice in the White Sea or in the area between Jan Mayen and East Greenland (the West Ice population). The Harp Seal is migrating searching for food over large areas in the Barents Sea, the Norwegian Sea, the Greenland Sea and the Denmark Strait. Age of maturation is 4–8 years, normal life length more than 30 years. An adult animal is about 1.9 m long with a weight around 200 kg.
The population size was in 2000 estimated to more than 300,000 animals in the White Sea and 361,000 animals in the West Ice.
The annual prey consumption was in 2000 estimated to about 3.5 million tonnes in the White Sea area (Nilssen et al 2000).

White Sea and west ice populations

Main article: seal hunting Seal hunting
Harp Seals eat a wide variety of fish and other sea creatures, and their diet seems to vary during different stages of life. Since reporting of the stomach contents of killed seals began in 1941, at least 67 species of fish and 70 species of invertebrates have been found to be part of the Harp Seal's diet. After the Canadian cod collapse many French fishermen and politicians blamed Harp Seals for the destruction and hindering the recovery of the North-West Atlantic Cod population. Although cod is a major contribution to Harp Seals diets, most of the cod is Arctic Cod and not the commercial Atlantic. The ratio is about 36:10 although the total tonnage of cod is around 200,000 tonnes. Although the effect of record population levels of harp seals on the recovery of the Atlantic cod stocks has been disputed, the accumulated evidence is such that most scientists now accept that cod populations are now in a seal predator trap. It is widely accepted that harp seals did not cause the collapse. However, a strong case can be made that both harp and hooded seals contributed to that collapse, as did other factors such as environmental change and marine community shifts. The issue with most regarding the cod stocks is that if the hunting were to stop, the population would grow and therefore cause total prey consumption to increase. Even with heavy hunting, from 1990 to 1999 there was a 800,000-tonne (32%) increase in fish consumption by seals. If the hunt were to stop, the belief is that the population would sky-rocket and within a few years more than likely double the consumption rate. The Harp Seal is at the top of its food chain and has few natural predators to keep its population at bay. For more information, review Northwest Atlantic Harp Seals Stock Status Report 2000 from the Canadian Government.