Harp seal

Harp seal. Photo Credit: Mike Hammill

Photo Credit: Mike Hammill

Figure 1. Range, migratory pathways and whelping locations of harp seals in the northwest Atlantic

Figure 1. Range, migratory pathways and whelping locations of harp seals in the northwest Atlantic

Size: Male and female harp seals are similar in size with adults averaging 1.6 m in length and weighing 130-150 kg.

Feeding habits and impact on the ecosystem: Harp seals eat a varied diet of fish such as capelin, Arctic cod, herring, sculpin, Atlantic cod, Greenland halibut, redfish, and plaice. They also consume crustaceans, shrimps and prawns.

DFO has conducted numerous studies on seal interactions, which evaluated the effects of seals on fish stocks. These results suggest that harp seal predation is not a significant factor in the lack of cod recovery to date, and that cod recovery is being affected by low productivity associated with low capelin. In the northern Gulf of St. Lawrence, the lack of cod recovery appears to be driven primarily by environmental conditions, followed by fishing and harp seal predation.

Reproduction and life cycle: Females bear a maximum of one pup per year, between late February and mid-March and require stable ice for giving birth and rearing their young. Newborn pups weigh around 11 kg and are 80–85 cm long. They are nursed, on average, for 12 days and gain over 2.2 kilograms per day. Once the pups are weaned, the females leave the ice to mate. The pups begin to moult their whitecoat at around 10 days old. By three weeks of age they have completed their moult and are referred to as a ‘beater’ because of the way in which they swim.

Lifespan: 25-40 years

Distribution: Harp seals are restricted to the north Atlantic where they are separated into three separate populations, each of which uses a specific pupping site. The Northwest Atlantic stock (Fig. 1), which is the largest, is located off eastern Canada and western Greenland. This population is further divided into three separate herds based on the breeding location. The Front component breeds off the coast of southern Labrador and northern Newfoundland, while the Gulf herd breeds near the Magdalen Islands in the middle of the Gulf of St. Lawrence. A third, smaller group may be found in the northern Gulf. A second stock, the Greenland Sea, pups off south east Greenland while the third stock (White Sea/Barents Sea) pups in the White Sea, in northern Russia.

Population trends: The Northwest Atlantic harp seal population is healthy and abundant with an estimated population of 7.4 million animals, almost six times what it was in the 1970s. There is some evidence to suggest that the Northwest Atlantic harp seal population may be reaching levels close to its natural carrying capacity, which is the maximum number of individuals of a particular species that can be sustained by that species’ ecosystem.

The harp seal population has remained between 7.0 and 7.8 million since 2004. This is thought to be due to a decline in herd productivity, which is probably related to food resources. Variable juvenile mortality, related to poor ice conditions, particularly in the Gulf of St Lawrence between 2010 and 2013 may have also contributed to this lack of increase. However, ice conditions have been very good for juvenile survival in 2014 and 2015. The Department is monitoring this situation closely, and any increased ice-related mortality this year will be taken into consideration when making future management decisions.

Conservation status in Canada: Harp seals are abundant, with an estimated population of 7.4 million animals and have not been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC).