Excerpted from an article by Barbara Lelli and David E. Harris, Ph.D.

Most people who navigate small boats in Maine coastal waters have encountered seals at one time or another. Gray seals, harp seals, hooded seals, and harbor seals are found in the Gulf of Maine. The most common seal species by far is the harbor seal. A 1997 aerial survey counted nearly 31,000 harbor seals in the Gulf of Maine, a three-fold increase compared to 1981.

The increasing seal population is, at least in part, a result of the fact that only recently have people stopped openly killing seals. In the past, harbor seals were hunted for food and clothing. More recently, people killed harbor seals in the belief that seals compete with humans for commercially valuable fish. Since 1972, the federal Marine Mammal Protection Act has protected seals. While this law now deters people from openly shooting and killing seals, more subtle human disturbances of seals persist.

Harbor seals are highly adapted to the marine environment. They swim, dive, feed, mate, and occasionally give birth in the water. They can even sleep or rest in the water. Seals are also excellent swimmers who can dive to over 200 meters and remain submerged for as long as 30 minutes. Despite these abilities, seals in the water are at risk of injury by power boaters, and propeller cuts are a common wound observed by those who rescue and rehabilitate injured seals. Kayakers, on the other hand, are unlikely to harm seals they encounter in the water. Indeed, seals often approach kayaks, seemingly as curious about us as we are about them. If you get too close, a seal can easily dive out of sight and swim away.

Harbor seals also come ashore and spend time on land, a behavior known as "hauling out." They haul out to rest and sleep on coastal islands and ledges at low tide. Humans have a harmful effect on harbor seals when our presence causes seals to abandon their haul-out and return to the water.

The majority of sea kayakers and other small boaters do not intend to harm wildlife. Even so, in a coastal setting with high boat traffic, boaters are the primary factor that determines whether or not seals haul out onto ledges. Here are some tips for small boaters who encounter seals:

• View from a distance: If you wish to view seals, use binoculars to view them from a distance. Viewing from land is preferable to viewing from the water. Stay far enough away so that the seals display no response at all to your presence. Keep a minimum distance of 100 yards between you and the seals.
• Do not approach a haul-out ledge: Give seals hauled out on ledges the widest berth possible. If you must pass a ledge on which seals are hauled out, hug the shoreline farthest from the ledge. Maintain a course parallel to a ledge and avoid sudden changes in direction or speed.
• Recognize when you are too close: You are too close if seals hauled out on ledges stretch their necks and chests into the air or start to move toward the water. If this happens, back off immediately. If seals do enter the water, leave the area. If you leave, seals may haul out onto the ledge again.
• Leave seals alone: Do not handle or attempt to "rescue" a seal pup that appears to be abandoned; its mother may return. If you see a seal pup or adult that appears to be abandoned or in distress, call the closest marine animal stranding organization. From Kittery to Rockland, call the Marine Animal Lifeline's 24-hour Rescue Hotline pager at 851-6625 (you will not need to dial 207 in Maine). From Rockland to the Canadian border, call Allied Whale, College of the Atlantic, at (207) 288-5644.
• Tell others: Tell other boaters about why it may be harmful to flush seals into the water, and about how to minimize their impact on seals.

Barbara Lelli is a Registered Maine Guide and David Harris is an assistant professor of natural and applied science at the Lewiston-Auburn campus of the University of Southern Maine.