Seals in the Sound: Harbor Seals Pinnipeds Taxonomy Seal Ecology Other Seals Key Links: Seal Cam Video Highlights Seal Behavior Videos Glossary FAQs Educator Resources

WESTERN ATLANTIC HARBOR SEAL
Phoca vitulina concolor

Size
Male and female harbor seals are sexually monomorphic. This is a scientific term that means males and females look almost identical which makes them very hard to tell apart. Harbor seals are around 5.5 feet long and weigh around 200 pounds. Males tend to be slightly larger than females.

Hair not fur
Harbor seals range in color from brown, tan, light grey and silver with dark spots. Their thick short coat is made of coarse guard hairs and finer, but denser under hairs. Each guard hair has three to six under hairs attached at the root. The density of their hair increases with age, but the hair provides only a small percentage of insulation for the seal. Glands in the skin secrete oil that helps to waterproof the hair.

Harbor seals molt, or shed their hair, each year after the breeding season (late summer to early fall). They gradually loose their hair in patches and it generally lasts one to two months. Pups shed a white coat called the languo shortly before or after birth.  The pups do not molt until they are one year old. Molting season is a great time to do population counts as the seals tend to stay inshore and spend more time hauled out.

Predators and Threats
Predators of the harbor seal vary around the northern hemisphere. Their major predators worldwide are killer whales, bears and sharks. Even eagles have been known to prey on seal pups. Coyotes, dogs and humans can threaten seals and cause them to retreat to the water. In New England, the major predators of seals are sharks but little is known about what preys upon seals in Long Island Sound.

Other threats to seals may be more of a concern in New England than predators. These threats include marine debris (trash), lost fishing gear and chemical pollution. These types of pollution can injure or sicken seals when they become entangled or poisoned.

Another threat to seals involves damage to their ecosystem. An ecosystem can be described as all the organisms (plants and animals), their interactions with each other and their habitat. In an ecosystem, all parts affect one another. Changes such as loosing fish species can really change an ecosystem and make it difficult for other animals like humans, seals, or sharks to find food. Some known threats to the Long Island Sound ecosystem are non-point pollution, over development along the shoreline that threatens salt marshes, improper disposal of chemicals such as oils and climate change.

Seals in the Sound: Harbor Seals | Pinnipeds | Taxonomy | Seal Ecology | Other Seals