The harbor (or harbour) seal (Phoca vitulina), also known as the common seal, is a true seal found along temperate and Arctic marine coastlines of the Northern Hemisphere. The most widely distributed of pinniped (walruses, eared seals, and true seals), they are found in coastal waters of the northern Atlantic and Pacific oceans, the Baltic and North Seas.
Harbor seals are brown, tan, or gray, with distinctive V-shaped nostrils. An adult can attain a length of 1.85 meters (6.1 ft) and a mass of 132 kilograms (290 lb). Females outlive males (30–35 years versus 20–25 years). Harbor seals stick to familiar resting spots or haulout sites, generally rocky areas (although ice, sand and mud may also be used) where they are protected from adverse weather conditions and predation, near a foraging area. Males may fight over mates underwater and on land. Females mate bear a single pup, which they care for alone. Pups are able to swim and dive within hours of birth, developing quickly on their mothers' fat-rich milk. Blubberunder their skins and helps to maintain body temperature.
Their global population is 5-6 million, but subspecies in certain habitats are threatened. Once a common practice, sealing is now illegal in many nations within the animal's range.
Individual harbor seals possess a unique pattern of spots, either dark on a light background or light on a dark. They vary in color from brownish black to tan or grey; underparts are generally lighter. The body and flippers are short, heads are rounded. Nostrils appear distinctively V-shaped. As with other true seals, there is no pinna (ear flap). An ear canal may be visible behind the eye. Including the head and flippers, they may reach an adult length of 1.85 meters (6.1 ft) and a weight of 55 to 168 kg (120 to 370 lb). Females are generally smaller than males.