Harbor seals inhabit the shores of oceans in the northern hemisphere. Color tends to vary from silver gray to almost black with dark blotches on their backs. Harbor seals have no external ears and their eyes are prominent. A newborn seal is covered with a coat of soft white or yellowish-white wool which is shed at the age of one or two weeks. The succeeding coat consists of short, stiff, course hairs without underfur.
Harbor seals feed on a wide variety of coastal fish and shellfish.
Because of their competition with commercial fishing interests, they are threatened with extermination. These seals scatter during mid-summer, but during the late summer they form in groups of all ages. In September, the mature seals swim to secluded areas where they mate in the water. Loosely organized colonies may be formed, but harbor seals do not establish harems as some other types of seals do. Their winter is spent away from the mainland.