Harbor seals are marine mammals commonly found along the coasts of the northern hemisphere. They have a streamlined body, a rounded head, and can vary in color from gray to brown with spots. Typically, they measure about 5 to 6 feet in length and weigh between 100 to 300 pounds. These seals are known for their playful behavior and can often be seen basking on rocks or beaches. They primarily feed on fish and invertebrates, using their sensitive whiskers to detect prey in the water. Harbor seals are social animals, often found in groups, but they can also be solitary.