By Jay R. Calkins
Seventy-five species of whales, dolphins and porpoises in the ocean all belong to the order Cetacea. They are the only mammals, other than manatees, that live their entire lives in the water. Some whales are huge. The blue whale, for example, grows to 100 feet in length and over 200 tons in weight. It is the largest animal that has ever lived on earth. Some whales, such as the dolphins, grow only three feet long.
Like other mammals, such as cats, dogs, deer, mice and humans, whales are warm-blooded. Whales breathe air and nurse their young. Whales may also be the most intelligent animals in the ocean.
Some whales, such as the bottlenose dolphin, sperm whale and killer whale, have teeth for grabbing and holding their food. Other whales, such as the right whale and the blue whale, do not have teeth. These whales have rows of baleen in their mouths for catching food. Baleen has many bristles like a broom used to trap small animals in the whale's mouth. Baleen whales eat mostly shrimp-like animals called krill, copepods. and small fish. Toothed whales catch larger prey including fish, squid and octopus. Killer whales even eat other large mammals such as seals and sea lions.
BALEEN WHALES
Examples of baleen whales are the right whale, blue whale, humpback whale, fin whale, and gray whale. These gentle giants were nearly hunted to extinction for meat and oil. The bones, too, were prized for carving decorative items, and the baleen was used for garment stays.
Baleen whales are the largest whales but they eat tiny food animals. Krill, related to shrimp, are smaller than your little finger and copepods are only the size of a grain of rice. Whales swim into a school of krill or small fish with their mouths open. They take in hundreds of gallons of water, close their mouths and squirt the water through the baleen. The baleen traps the krill and other small animals and the whale swallows them. A single whale can eat several tons of krill a day.
Cold waters in the North and South Atlantic Ocean and the North and South Pacific have many schools of krill and small fish. Whales like to feed in the cold oceans where there is an abundance of their favorite food. Some whales are known to migrate into warm waters to bear their calves.
The migration of the gray whale is well known. They travel thousands of miles in the Pacific Ocean from Alaska down the west coast of the United States to the Baja Peninsula in Mexico, where they bear their young.
RIGHT WHALE
The right whale also migrates from cool waters to warm waters (Fig. 7). In the summer, right whales are found in the Gulf of Maine and Bay of Fundy. In the winter, right whales are found with calves near the Georgia and Florida coasts.
Northern right whales have been seen in the North Atlantic, on the western side, as far south as the Gulf of Mexico and as far north as the Newfoundland coast and Labrador. Sightings also occur in the Bay of Fundy and southern Nova Scotia. Spring concentrations occur off Cape Cod, probably of animals moving north from breeding grounds in South Georgia near the Florida border.
Right whales are the only large baleen whales regularly seen along the southeastern coast of the United States. They have been adopted as the official marine mammal for the State of Georgia. The right whale was heavily hunted by commercial whalers until the 1950s. The right whale got its name because it was the "right whale to kill. It was a slow swimmer, produced large amounts of oil and baleen, and it floated after it was harpooned. These characteristics made the right whale a favorite target for whalers.
Scientists estimate that between 200 to 300 right whales may be left in the western North Atlantic population. Other populations of right whales are found along the South African coast and along the coast of Argentina. These populations of whales apparently do not mix with each other.
Right whales are so rare that many people fear that they are doomed to extinction. They are among those protected by the Endangered Species Act.
Achieving a length of 60 feet and weight of up to 100 tons, right whales are magnificent beasts. They are generally black in color with some white on their chin and have large heads, which take up nearly 1/3 of their body length. The whales can also be recognized by white, crusty growths on their heads called callosities. They also have no dorsal fin.
Right whales have been seen swimming along the surface of the ocean with their mouths open to catch food. This behavior has been seen only in cold northern waters. Feeding has not been observed off the Georgia and Florida coasts where mostly female whales are seen with their calves.
It is a puzzle why the gray whale of the Pacific has recovered from being heavily hunted while the right whale has not. Laws protecting these whales are equally strong and have been enforced for an equal amount of time. Gray whales have increased from near extinction to 16,000 individuals since the 1950s. Right whale populations have not increased during the same time period. This leads scientists to believe that other environmental problems such as water pollution and collisions with and sounds from ships may affect the right whales more than the gray whale. One concern is that the right whale may disappear entirely before we can learn enough about it to help it recover.
TOOTHED WHALES
Toothed whales have cone-shaped teeth in their mouths for catching food. The most common foods for these whales are fish and squid. Toothed whales include the sperm whale, narwhal, pilot whale, beluga, porpoises. killer whales and dolphins. Yes, dolphins are whales! Do not confuse dolphin, the whale, with dolphin the fish. Dolphin, the fish, is a favorite dish in seafood restaurants. Dolphin, the whale, is not caught for food.
Toothed whales generally are much smaller than the baleen whales. One exception is the sperm whale, which can grow to 60 feet in length. The sperm whale is the subject of a whaling ship's quest in Herman Melville's novel "Moby Dick." The sperm whale can dive to a mile in depth and stay down an hour or more.
A notable feature of the toothed whales is a great rounded forehead called a ''melon". The melon is used as a "second-sight" sense much like sonar is used by navy ships to locate objects underwater. Even blindfolded, toothed whales can find objects around them.
Some toothed whales are capable of great bursts of speed up to 30 miles per hour. Dolphins can jump over 15 feet out of the water. This is quite amazing considering they weigh 300 to 400 pounds. The sperm whale was seriously hunted, but most toothed whale populations were not as devastated by whalers as the baleen whale populations. Since most whaling ceased in the 1950s, sperm whale populations have increased in number.
Toothed whales have been found stranded on beaches, sometimes in large numbers. Whales travel in groups or "pods". Pilot whale pods have been known to follow a sick leader into shallow water where they often die. Dolphins have also been found stranded in large numbers on the east coast of the United States. Some scientists blame diseases induced by human pollution for this stranding behavior.
Large numbers of dolphins are caught in drift nets set out to catch tuna and other fish. Dolphins caught in these nets often cannot get to the surface to breathe, so they drown. International efforts are under way to stop drift net fishing.
Despite the problems facing toothed whales, bottlenose dolphins are very numerous along the southeastern coast of the United States. They can be seen traveling in small pods near almost any beach or in tidal creeks.
The bottlenose dolphin may be the most familiar of all whales since they are common performers at large marine aquariums. Bottlenose dolphins were also filmed for the popular television show "Flipper".
Dolphins feed mostly on fish. They can be seen herding fish in teams much like cowboys herding cattle. Dolphin pods "talk" to each other with a large vocabulary of sounds including squeals and clicks. Some scientists are trying to learn the language of whales in order to understand their behavior better. Think what we could learn about the ocean if we could talk to a dolphin!
Dolphins and other whales usually have only one calf every other year. The calves are born tail-first and then quickly boosted to the surface by the mother for their first breath of air. Other females in a pod will often care for the newborn calf. Whale mothers nurse their calves underwater. Milk is forcibly squirted through the mother's nipples to feed the calf. Some whale calves will double their weight in only a week.
Whale populations that produce so few young in a season can be quickly brought to the brink of extinction by heavy hunting pressure. Conservation groups have convinced the International Whaling Commission to stop most whaling. Native American hunters, such as the Eskimos, who rely on whale meat and other wild game to feed their communities, are still allowed to hunt a limited number of whales. We must all work together to make sure that conservation measures continue to protect whales and keep these wonderful animals from disappearing forever.