Citation: Endangered Marine Mammals. The Marine Mammal Center.<http://www.marinemammalcenter.org/learning/education/mammalinfo/endanger.asp>

An endangered animal or plant is a species that is considered in immediate danger of becoming extinct. Its population is very small and it needs active protection to survive. In the United States, hunting of endangered animals is not allowed. Neither is importation of their meat, fur, tusks, blubber, or other products.

Extinction has happened throughout history, but in modern times the rate has increased dramatically. There is a link between the increase in the extinction rate and the growth in human population. The worldwide human population was 1 billion in 1600, 1.5 billion 100 years ago, and is over 6 billion today. At the same time, the species extinction rate has increased to one species a day. If this continues, it will cause a dramatic drop in the diversity of life on our planet, which will most certainly have serious effects.

Increasingly, people crowd out places for wild plants and animals to live. Some animals and plants can survive in only one specific type of habitat, and when their habitat disappears, so

do they. Some areas have become too polluted and unhealthy for animals and plants to survive. Recreational activities also interfere with wildlife. For marine mammals, there is the special problem of accidental entanglement in fishing nets and collisions with boats.

Marine mammals that are on the endangered or threatened species list include southern sea otters, manatees, Guadalupe fur seals, monk seals, humpback, blue, fin, sei, right and bowhead whales. The western Pacific population of the

Steller sea lion was added to the endangered list in 1997 in response to an 80% drop in its population over the last 30 years. The eastern population is still listed as threatened.

Most of the large whale populations initially became low due to hunting. For instance, blue whales, the largest animals on earth, once numbered 200,000. Today the worldwide population is estimated to be 10,000. Other whales, such as the humpback, right, and bowhead are still endangered, despite being protected.

In contrast, the gray whale population has made a comeback and has been taken off the endangered species list. The return of the gray whale might be explained by some habits they have that are not shared by the other baleen whales. Virtually all gray whales migrate to the same place every year, therefore, they can more easily find a mate. Additionally, most females produce one calf every other year, therefore, they have a relatively high birth rate.

Many marine mammal scientists are now becoming concerned with the drop in numbers of dolphins and porpoises. River dolphins that live in Asia and the Amazon are disappearing due to dam building and habitat destruction. Another concern is the number of dolphins dying in the tuna fisheries of the eastern tropical Pacific. Historically, yellowfin tuna has been caught by encircling the dolphins that swim above the tuna with purse seine nets. Over 100,000 dolphins per year died in the 1970s and early 1980s after being caught in tuna nets, and several species of dolphins in the eastern tropical Pacific are now considered depleted under the Marine Mammal Protection Act. Efforts of environmental organizations and consumers led to "dolphin-safe" labeling of canned tuna, and a 98% reduction in dolphin mortality since 1990. However, recent changes in US and international laws have reopened this complex issue, and the outcome is in doubt. Fortunately, the major companies have all promised to sell only tuna that is caught without encircling dolphins. For more information on the tun-dolphin issue, go to the Earth Island Institute home page or the National Marine Fisheries Service Dolphin Interactions with the Eastern Tropical Pacific Tuna Purse Seine Fishery page.

Another marine mammal, the southern sea otter, was driven to the verge of extinction from being hunted for its fur. The California sea otter population, once over 250,000, today numbers around 1,925. Although protected, sea otters remain very vulnerable to oil spills; oil soils their fur, destroying its insulating capabilities, which leads to hypothermia. In addition, new diseases and parasites are infecting sea otters and causing a decline in their populations.

Many marine mammals in the seal family also suffered a similar fate from hunting. The Guadalupe fur seal once ranged into California, and now its population is reduced to 7,400, centered around Guadalupe Island in Mexico. Northern elephant seals were once hunted

for their oil. Although they were once endangered with fewer than 100 individuals in the late 1800s, their population now has recovered to over 150,000. In recent years, many seal and sea lion species in Alaska have declined including populations of northern fur seals, harbor seals, and Steller sea lions. It is believed that one of the major reasons for their decline is accidental catch in fishing operations and competition for food with commercial fisheries.

Other marine mammals, such as the Steller sea cow, Caribbean monk seal, and certain whale stocks, have actually become extinct in historic times. The Steller sea cow was discovered in 1741 by the Vitus Bering expedition. Due to over hunting for its meat, the sea cow vanished in 1768, within 27 years of its discovery.

Unfortunately, a relative of the Steller sea cow, the West Indian Manatee, is now in severe danger of extinction. In 1989, the estimated manatee population in Florida was 1,200. The following year over 140 manatees died. Human causes were responsible for 75% of these deaths, and the single biggest cause of deaths was attributed to being hit by boats. Manatees are very slow movers and sometimes sleep near the surface of the water. Motor boat encounters often result in severe injuries and broken bones. Manatee reserves have been set up, but death rates are still high, probably due the popularity of motor boating and growth in Florida population. Manatees give birth only every three years or so. Unless drastic measures are taken, manatees could become extinct.

You can help protect endangered marine mammals. You can 1) support non-profit organizations like The Marine Mammal Center, working to rescue and protect marine mammal species; 2) support legislation that helps keep the ocean clean and protects habitat; and 3) make wise choices as consumers. You can use products that are biodegradable and less harmful to the environment. You can recycle bottles, aluminum, paper, and plastics, which helps to protect habitat. You can choose recreational activities that do not disturb habitat or wildlife. You can avoid buying products that endanger wildlife and plants such as tuna (non-dolphin-safe), ivory, wild animal fur and feathers, and tropical woods. We also need to pressure government to come up with effective recovery programs for endangered species. Write to your legislators to voice your support. Together, we can help protect the rich variety of life on earth.

Each of the endangered Marine Mammals Information:

SEA OTTEREnhydra lutrismeaning of scientific name: otter

DESCRIPTION: Sea otters are members of the weasel or mustelid family. Like other members of this family, they have very thick fur. In fact, at 850,000 to one million hairs per square inch, they have the thickest fur of any mammal. Their fur actually consists of two layers, an undercoat and longer guard hairs. This system traps a layer of air next to their skin so their skin does not get wet. Sea otters are usually dark brown, often with lighter guard hairs. Alaskan sea otters tend to have lighter fur on their heads. Sea otters are the smallest marine mammal. Adult females weigh 35-60 pounds (16-27 kg); males reach up to 90 pounds (40 kg). Alaskan sea otters are bigger with males weighing up to 100 pounds (45 kg).

RANGE/HABITAT: Sea otters once ranged from Mexico to Alaska and even to Japan. Currently, the California population numbers around 2,000 and is found from Half Moon Bay to Morro Bay. There is a much larger population in Alaska, and sea otters are still found in Russia. Sea otters inhabit shallow coastal areas and prefer places with kelp. The kelp acts as an anchor that the sea otters use to wrap themselves in when they are resting.

BEHAVIOR: Sea otters are social animals, with females and pups spending time together in one group and males in another. Pups stay with their mothers for the first eight months of their life. The pups' fur traps so much air that they actually cannot dive under water. When mothers leave the pups wrapped in kelp to hunt, pups bob on the surface of the ocean like a cork. Mothers spend much time grooming pups and often carry them on their chests. Pups begin to learn to swim at around four weeks of age.

Sea otters are one of the only marine mammals to use tools. They eat animals with shells, like clams and abalone, and use a stone to break open the shells. When sea otters are under water searching for food, they store what they have found in the loose skin folds at their armpits. Adult sea otters can eat 25%-30% of their body weight in one day!

MATING AND BREEDING: Females usually have their first pup at the age of four or five. Their pregnancies last four to five months. Pups can be born any time of year, but in California, most are born between January and March, and in Alaska, most are born in the summer. When born, the pups weigh from three to five pounds.

STATUS: Sea otters in California are a threatened species due to past over hunting for their beautiful fur. Although sea otters are protected now, they remain vulnerable, especially to oil spills. Unlike other marine mammals, sea otters do not have a blubber layer. Therefore, they rely on their fur to keep warm. If their fur is oiled, it loses its insulating qualities and the sea otters soon chill. Otters are also affected by the oil fumes or poisoned by eating food exposed to oil. Most sea otters quickly die in an oil spill. Several thousand sea otters died in the 1989 Exxon oil spill in Valdez, Alaska. Other threats to sea otters include infectious diseases, parasites, boat strikes, entanglements, and toxins.

AT THE MARINE MAMMAL CENTER: The Marine Mammal Center began rehabilitating sea otters in 1995. Since that time, we have rescued up to 45 sea otters. The various reasons for their care at The Marine Mammal Center are infectious diseases, the most common being parasite infection, and separation from their parents.

WEST INDIAN MANATEETrichechus manatus

DESCRIPTION: Manatees and their relatives are the only vegetarian marine mammals. They are sometimes known as sea cows, and, like cows that live on land, they eat grass -- but sea grass. They weigh up to 3,500 pounds (1,600 kg) and reach 13 feet (4 m) in length. They have a mermaid-like tail. In fact, manatees probably inspired the legends about sirens, or mermaids, who beckoned sailors at sea, as their scientific classification suggests: they are in the Order Sirenia.

RANGE/HABITAT: Today manatees are rare or extinct in most of their range. They are found in slow moving rivers, estuaries, saltwater bays, canals, and coastal areas where sea grass flourishes. The largest population is in Florida where they concentrate in the winter. In summer, Florida manatees are found as far west as Louisiana and as far north as the Carolinas and Virginia. They are also found in the coastal waterways of Central and South America. Manatees have a low metabolic rate and need to be in water 68°F and above. They are subject to hypothermia in waters below 60°F.

BEHAVIOR: Manatees are harmless and are the slowest marine mammal. They have no defense system except for fleeing, and do not fight for food or territory. They have few natural enemies, except man. Manatees eat 100 to 150 pounds (45-68 kg) of plants per day. Their big appetites and grazing helps to keep waterways free and flowing. When they are not eating, they are usually sleeping. However, they are known to body surf. Because of their need for warm water, manatees often congregate in the warm water effluents from power plants. Manatees communicate with squeaks and squeals. They are very tactile, "kiss" each other in greeting, and nuzzle snout to snout. They embrace with their flippers.

MATING AND BREEDING: Manatee birth rate is quite slow, since females give birth to a single calf only every two to three years, and calves remain dependent for two years.

STATUS: Manatees are an endangered species. The 2001 manatee population count was 3,276, the highest since the counts began in 1991. However, scientists are concerned that too many manatees are dying each year to keep the population growing or at least stable. Since 1985, manatees' deaths have averaged over 100 per year, with about 30% of those deaths attributed to human causes such as boat strikes. Manatees are subject to this problem as they are slow moving and often sleep near the water's surface. Many manatees that survive boat encounters bear scars as evidence of the incident.

A Pacific relative of the manatee, the Steller Sea Cow, became extinct in the 1700s within 27 years of its discovery by explorers. Let us not let this happen to the manatee! The manatee could be helped by setting up more extensive reserves, and by enacting and enforcing stricter boating regulations. Write the Governor of Florida or your congressperson about

your manatee concerns. Spread the word to friends. Let us help the manatee before it is too late.

GUADALUPE FUR SEALArctocephalus townsendimeaning of Latin name: bear-headed, and towsendi comes from C.H. Townsend, who first studied these animals

DESCRIPTION: Little is known about Guadalupe fur seals, because they were hunted almost to extinction before researchers began to study them. Being a member of the otariid (sea lion) family, they have external ear flaps and they have long front and hind flippers, which they use to "walk" when on land. They are similar to northern fur seals in appearance but are slightly smaller, and the males are lighter brown. Adult male Guadalupe fur seals also have a larger head and a long, pointed muzzle. Males reach six feet (1.8 m) and 300 pounds (136 kg), while females grow to four feet (1.2 m) and 100 pounds (43 kg). By looks alone, juvenile Guadalupe fur seals are very difficult to tell apart from juvenile California sea lions and northern fur seals.

RANGE/HABITAT: There is evidence that Guadalupe fur seals once bred as far North as Point Conception in central California. Due to hunting, they became extinct in California waters by 1825. Today, the only known breeding colony is on Guadalupe Island, off the Mexican coast. Increasing numbers have been seen in California's Channel Islands, and in recent years, several Guadalupe fur seals have stranded along the central California coast. It is not yet known whether these strandings are a result of El Niño events (warmer water pushing their prey northward), or a sign of Guadalupe fur seals returning to their former range because four Guadalupe fur seals stranded in 1999, a non-El Niño year.

BEHAVIOR: Little is known about their behavior or their diet, but they seem to eat squid and lanternfish.

MATING AND BREEDING: The breeding strategy of Guadalupe fur seals appears to be similar to that of northern fur seals and other types of sea lions. Males hold territories and breed with many females, and pups are born from mid-June to mid-July. Guadalupe fur seals tend to stay near shore and breed in caves on Guadalupe Island rather than on open beaches. There is evidence that they once bred on the rocky beaches of Guadalupe Island, and some scientists speculate that hunting pressure pushed them back into caves for protection.

STATUS: Guadalupe fur seals were not identified as a new species until 1897. By that time, they were already thought to be extinct. Scientists did not know what a living Guadalupe fur seal looked like until 1928, when a few dozen fur seals were discovered on Guadalupe Island, two of which were brought to the San Diego Zoo. The breeding colony was not reestablished until 1954, and has been growing slowly since then. Today's population is

estimated to be about 7,400. Guadalupe fur seals are now protected by law in the United States and in Mexico, and Guadalupe Island has been designated a pinniped (seal and sea lion) sanctuary. Hopefully, this protection will restore the Guadalupe fur seal to its former range, and we will see them thrive again off the California coast.

AT THE MARINE MAMMAL CENTER: The Marine Mammal Center has rescued only a few Guadalupe fur seals. Of those that have been successfully rehabilitated, one was brought in because it was entangled with fishhooks in its nose, mouth, and tail and was also underweight. An adult female with an attached satellite tag was released from The Center in 1998 and swam back to Guadalupe Island within two weeks of being released.

HUMPBACK WHALEMegaptera novaeangliaemeaning of scientific name: large-winged of New England

 

DESCRIPTION: The humpback whale was given its common name because of the shape of its dorsal (back) fin and the way it looks when the animal is diving. Its scientific name, Megaptera, means, "large-winged" and refers to its long, white, wing-like flippers that are often as long as one-third of the animal's body length. Humpbacks are gray or black, except for the flippers, parts of the chest and belly, and sometimes the underside of the tail flukes. Each whale has its own unique pattern on the underside of its tail flukes, which can be used like"fingerprints" to identify individual whales. Unique to humpbacks are wartlike round protuberances (bumps or tubricales) that occur on the head forward of the blowhole and on the edges of the flippers. Humpbacks are baleen whales that have 14 to 35 long throat pleats that expand when the whale takes in water while feeding.

Northern Hemisphere humpbacks reach an average length of 49 to 52 feet (15-16 m), and southern humpbacks reach 60 feet (18 m). Females are generally larger than the males. The average weight for a mature adult is 35 to 50 tons.

RANGE/HABITAT: Humpbacks are found in all oceans to the edges of polar ice, and follow definite migration paths from their summer feeding grounds to warmer waters in the winter. There seem to be three distinct populations of Humpbacks that do not interact with one another: one in the North Pacific, one in the North Atlantic, and another in the Southern Hemisphere (south of the equator). In the North Pacific, where their populations reach 15,000, humpbacks feed in the summer along the coast from California to Alaska. In the winter, they migrate to breeding grounds off of Hawaii, Mexico, Costa Rica, and Japan. The population in California migrates to Mexico and Costa Rica, whereas the Alaskan population migrates to Hawaii.

BEHAVIOR: Acrobatic humpbacks regularly breach (jump out of the water), stroke each other, and slap the water with their flippers and flukes. Scientists believe these activities are forms of communication because they create a great deal of noise, which can be heard

at long distances under water. Humpbacks swim in groups or pods of up to a dozen at calving grounds, and in smaller groups of three to four during migration. Unlike other baleen whales, they can often be seen feeding cooperatively.

In feeding, they use baleen plates to strain other small fish such as krill or herring, and plankton out of the water. Their 270 to 400 baleen plates are dark and each is about two and a half feet long. Humpbacks use several different feeding methods. While "lunge feeding," they plow through concentrated areas of food with their huge mouths open, swelling with large quantities of food and water. During "bubble net feeding," which is unique to humpback whales, one or several whales blow a ring of bubbles from their blowholes that encircle a school of krill or fish. The whales then swim through the "net" with their mouths agape, taking in large amounts of food.

Humpbacks are best known for their haunting vocalizations or "singing." They have a rich repertoire that covers many octaves and includes frequencies beyond the threshold of human hearing. These songs, apparently sung by males, last as long as 20 minutes, after which they are repeated, often with slight changes. Each year, the song undergoes changes from the year before, but all males sing the same song. When a whale is singing, it floats suspended in the water, head down and relatively motionless. Behavior such as dominance, aggression, and mate attraction may be related to singing.

MATING AND BREEDING: Females give birth every two or more years. Pregnancies last for 12 months. The calves nurse for eight to eleven months. When weaned, the calves are 24-27 feet (8-9 m) long.

STATUS: Humpbacks are among the most endangered whales and fewer than 10% of their original population remains. However, in recent years, humpbacks have been observed more and more frequently feeding along the California coast. Approximately 800 humpbacks feed along the California Coast in the Summer and Fall.

AT THE MARINE MAMMAL CENTER: Probably the most famous humpback whale is "Humphrey," who was rescued twice by The Marine Mammal Center and other concerned groups. The first rescue was in 1985, when he swam into San Francisco Bay and then up the Sacramento River. Five years later, Humphrey returned and became stuck on a mudflat in San Francisco Bay near 3 COM Park. He was pulled off the mudflat with a large cargo net and the help of a Coast Guard boat. Both times he was successfully guided back to the Pacific Ocean using a "sound net" in which people in a flotilla of boats made unpleasant noises behind the whale by banging on steel pipes, a Japanese fishing technique known as "oikami." At the same time, the attractive sounds of humpback whales preparing to feed were broadcast from a boat headed towards the open ocean. Since leaving the San Francisco Bay in 1990 Humphrey has been seen only once, at the Farallon Islands in 1991.

BLUE WHALEBalaenoptera musculusmeaning of scientific name: mouse-like finned whale (many think the name was meant as a joke, since blue whales are so large)

DESCRIPTION: It is difficult to imagine the size of the blue whale, the largest animal inhabiting the earth. There are records of individuals over 100 feet (30.5 m) long, but 70-90 feet (23-27 m) is probably average. A good way to visualize their length is to remember that they are about as long as three school buses. An average weight for an adult is 200,000 to 300,000 pounds (100-150 tons). Its heart alone is as large as a small car.

Blue whales are an overall blue-gray color, mottled with light gray. Cold water diatoms adhere to their skin and sometimes give their bellies a yellowish tinge, giving the blue whale its nickname of "sulfur bottom." Blue whales are long and streamlined. Their dorsal fins are extremely small, and their pectoral flippers are long and thin. Blue whales are rorqual whales, a family of baleen whales with pleated throat grooves that expand when the animal takes in water while feeding. In blue whales, 55-68 throat grooves extend from the throat to the navel. Blue whale baleen is black with over 800 plates.

RANGE/HABITAT: Blue whales have been found in every ocean of the world. Blue whales swim individually or in small groups. Pairs are very commonly seen. Approximately 2,000 blue whales live off the California Coast and migrate to Mexico, and Costa Rica.

BEHAVIOR: The favorite food of these giants is krill, or shrimp-like euphausiids, that are up to three inches long. Blue whales must eat two to four tons of krill a day during the feeding season. They concentrate on feeding during the polar summers primarily around the Channel Islands, Monterey Bay, and the Farallon Islands/Cordell Bank. During the winter months, they migrate to the warmer waters in Mexico and Costa Rica.

MATING AND BREEDING: Females give birth to calves every two to three years. They remain pregnant for about one year before giving birth. When born, the blue whale calf is about 23 feet (7 m) long and weighs 5,000 to 6,000 pounds (2,700 kg). A nursing blue whale mother produces over 50 gallons (200 liters) of milk a day. The milk contains 35 to 50% milk fat and allows the calf to gain weight at a rate of up to 10 pounds an hour or over 250 pounds (44 kg) a day! At six months of age and an average length of over 52 feet (16 m), the calf is weaned. The blue whale reaches sexual maturity at around 10 years of age.

STATUS: The blue whale was too swift and powerful for the 19th century whalers to hunt, but with the arrival of harpoon cannons, they became a much sought after species for their large amounts of blubber. The killing reached a peak in 1931 when 29,649 blue whales were taken. By 1966, blues were so scarce that the International Whaling Commission declared them protected throughout the world. Today, there are probably fewer than 15,000 blue whales in the oceans, and they are considered an endangered species. However, we can see them in the summer and fall off the central California coast, feeding in such places as the Gulf of the Farallones and Cordell Bank National Marine Sanctuaries. The 2,000 blue whales that feed along the California coast make up the largest concentration of blue whales in the world.

STELLER OR NORTHERN SEA LION Eumetopias jubatusmeaning of Latin name: having a broad forehead and mane

DESCRIPTION: Steller or northern sea lions are sometimes confused with California sea lions, but are much larger and lighter in color. Males may grow to 11 feet (3.25 m) in length and weigh almost 2,500 pounds (1120 kg). Females are much smaller, and may grow to nine feet (2.9 m) in length and weigh 1,000 pounds (350 kg). Steller sea lions are light tan to reddish brown in color. They have a blunt face and a boxy, bear-like head. Adult males do not have a visible sagittal crest (the bump on the top of their heads) as is seen in adult male California sea lions. Stellers have a bulky build and a very thick neck, which resembles a lion's mane, hence the name "sea lion."

RANGE/HABITAT: Stellers are found throughout the North Pacific Rim from Japan to central California. Unlike California sea lions, Stellers tend to remain off shore or haul out in unpopulated areas. Breeding occurs along the North Pacific Rim from Año Nuevo Island in central California to the Kuril Islands North of Japan, with the greatest concentration of rookeries (breeding grounds) in the Gulf of Alaska and Aleutian Islands.

MATING AND BREEDING: Pups are born on offshore islands from mid-May to mid-July, and weigh 35-50 pounds (16-23 kg). Mothers stay with pups for one to two weeks before hunting at sea. Then they spend roughly equal amounts of time hunting and nursing pups on land. Pups usually nurse for a year, but some continue to nurse for up to three years. Mating occurs 10-14 days after the pups are born. Dominant mature males maintain territories for one to two months and mate with many females. During the breeding season, males do not eat.

BEHAVIOR: Steller sea lions eat a variety of fishes, invertebrates, and occasionally other pinnipeds. Known predators are killer whales (orcas) and white sharks.

STATUS: The current population of Steller sea lions is about 40,000, with about 500 living in California. However, there is great concern about this population, which has dropped by 80% in the last 30 years. In 1997, the western stock in Alaska was listed as endangered and the eastern stock of the Continental United States and Canada was listed as threatened. Reasons for this decline are not known. However, researchers believe that a decline in the fish they eat is the biggest cause. The decline of fish could be due to increasing commercial fisheries in the Gulf of Alaska. Drowning, entanglement in nets, and gunshot are all possible reasons for the Stellers' decline. Stellers are protected under the Marine Mammal Protection Act, which forbids the killing, harming, or harassing of any marine mammal, as well as the Endangered Species Act. With this federal protection, there is hope for the recovery of the Steller sea lion population.

AT THE MARINE MAMMAL CENTER: The Marine Mammal Center has not rescued many Steller sea lions because they haul out on offshore rocks. Most Steller sea lions that The Center rescues are orphaned pups. In addition, Stellers are susceptible to many of the same diseases as California sea lions, such as leptospirosis and San Miguel sea lion virus. Because

of their threatened status, Steller sea lions released from The Center are fitted with a satellite tag. This has enabled us to track their movements. To date, the three Steller pups released, Artemis, Mozart, and Bethoven, have thrived in the wild; foraging and hauling out with other Steller sea lions.

DOLPHINS AND PORPOISESDelphinidae and Phocoenidae

People have long been fascinated with dolphins and porpoises. They have been celebrated in art and literature since ancient Greek times. Even today, dolphins and porpoises are among the most popular animals. Few people would forget an encounter with dolphins, especially one in which a group of wild dolphins comes over to a boat to bowride (surf the wave that the boat makes as it travels through the water).

Dolphins and porpoises are cetaceans, which are mammals in the whale family. Dolphins and porpoises are considered to be small whales. All dolphins and porpoises are toothed whales, or odontocetes. However, dolphins and porpoises differ in the type of teeth they have. Dolphins have sharp conal teeth, while porpoises have teeth that are spade or shovel shaped. In fact, scientists generally use tooth shape as a way of classifying an animal as a dolphin or a porpoise. Dolphins generally tend to have a pointy mouth or "beak" and a curved dorsal fin, but there are exceptions.

All dolphins and porpoises use echolocation, which is something like the sonar used on ships. Dolphins and porpoises produce a sound in the air passages in their heads, which they then send from the front of their heads. There, an oil-filled organ called the melon, focuses or directs the sound. A sound wave might hit an object, such as a fish, and the sound wave then bounces, or echoes back to the dolphin or porpoise. They can use this echo to tell what kind of fish or other object it hit, how large it is, and much more information about their environment. It is like seeing with their ears, but in some ways even better!

Dolphins and porpoises tend to be very social animals, living in groups. Sometimes thousands of individuals are seen together. Dolphin and porpoise mothers generally take care of their calves for one to two years until they are old enough to survive on their own. Like all mammals, they provide milk to their young.

Dolphins and porpoises are found in virtually all oceans and major seas of the world. One family, the river dolphins, is even found in large freshwater rivers such as the Amazon in South America and rivers in China and India. Dolphins and porpoises range in size from the Orca (killer whale) at a maximum of 30 feet (9.5 m) in length and a weight of up to eight tons, to the small vaquita, five (1.5m) long and weighing less than 200 pounds (90 kg).

In the Pacific off the California Coast, several species of dolphins and porpoises are found. They include the beautiful, fast, black and white Dall's porpoise, the numerous but shy

harbor porpoise, the gregarious and friendly Pacific white sided dolphin, common dolphins, and the deep diving Risso's dolphin.

Large numbers of dolphins and porpoises are a sign of the health and vitality of our oceans. But unfortunately, tens of thousands of porpoises and dolphins are dying every year due to problems caused by people. Many accidentally get caught in fishing nets and drown. Others get entangled in old nets, which are loose and floating freely. Many near-shore dolphins and porpoises are exposed to pollution and toxins that can make them sick. In recent years, large numbers of sick and dying bottlenose dolphins have washed up on the East Coast of the United States. In some places, people still catch and eat dolphins and porpoises for food or to use as fishing bait.

Many scientists are concerned that dolphins and porpoises now need to be protected in the same way that people worked to save and protect large whales from hunting in the recent past. You can help dolphins and porpoises by keeping informed on current issues, by writing to government officials about your concerns, and by supporting laws that protect dolphins and their ocean home. You can also recycle your trash and use less plastic (which is dangerous to these animals), buy products that are dolphin safe, and participate in beach clean ups.

NORTHERN ELEPHANT SEALMirounga angustirostrismeaning of Latin name: having a narrower snout than the southern elephant seal

DESCRIPTION: Elephant seals are well named because their large noses resemble an elephant's trunk. Males begin developing this enlarged nose, or proboscis, at sexual maturity (about three to five years), and it is fully developed by seven to nine years. Adult males may grow to over 13 feet (4 m) in length and weigh up to 4,500 pounds (2,000 kg). The females are much smaller at 10 feet (3 m) in length and 1,500 pounds (600 kg). The northern elephant seal is the second largest seal in the world, after the southern elephant seal.

The elephant seal is in the phocid, or true seal, family. It lacks external ear flaps and moves on land by flopping on its belly. The elephant seal has a broad, round face with very large eyes. Pups are born with a black coat which is molted, or shed, at about the time of weaning, revealing a sleek, silver-gray coat. Within a year, the coat will turn silvery brown.

RANGE/HABITAT: Northern elephant seals are found in the North Pacific, from Baja California, Mexico to the Gulf of Alaska and Aleutian Islands. During the breeding season, they live on beaches on offshore islands and a few remote spots on the mainland. The rest of the year, except for molting periods, the elephant seal lives well off shore (up to 5,000 miles, or 8,000 km), commonly descending to over 5,000 feet (1,524 m) below the ocean's surface.

BEHAVIOR: While living in the open ocean, northern elephant seals spend a lot of time diving, up to two hours at a time. They rarely spend more than four minutes at the surface

of the water between dives. It is believed that they eat deep-water, bottom-dwelling marine animals such as ratfish, swell sharks, spiny dogfish, eels, rockfish, and squid. Elephant seals molt each year between April and August, shedding not only their hair but also the upper layer of their skin as well. This is known as catastrophic molt.

MATING AND BREEDING: Each winter, elephant seals arrive at their breeding beaches in Mexico and California. Males are the first to arrive and they fight each other to establish dominance. During this time, dominant males will often inflate their noses and produce a noise that sounds like a drum to warn lesser males away. Females soon arrive, and associate with dominant males. Several days after coming onto the beaches the females give birth to the pups they have been carrying since last year. Pups weigh 75 pounds (35 kg) or more and are about four feet (1.25 m) in length. The pups nurse for about 28 days, generally gaining about 10 lbs (4.5 kg) a day. Around the time of weaning, the mother will mate with one or more of the dominant males. After the nursing period, the mother returns to sea. For the next two months, weaned pups, called weaners, remain on rookery beaches, venturing into the water for short periods of time, perfecting their swimming and feeding abilities. Eventually, the pups will learn to feed on squid, fish, and occasionally small sharks.

STATUS: The northern elephant seal is a conservation success story. They were hunted to the brink of extinction, primarily for their blubber, which was used for lamp oil. By 1910, it is estimated that there were less than 100 elephant seals, all found on Guadalupe Island off Baja California, MX. Today, the northern elephant seal population is over 150,000 and is probably near the size it was before they were over-hunted.

AT THE MARINE MAMMAL CENTER: From approximately mid-February through the end of June, The Center's rescue and rehabilitation work focuses on orphaned elephant seal and harbor seal pups. Usually these mammals are washed away from the rookery during a storm and found stranded on public beaches or along the rocky shorelines. These pups are usually underweight. They also suffer from other diseases such as northern elephant seal skin disease, parasites, and pneumonia.

NORTHERN FUR SEALCallorhinus ursinusmeaning of Latin name: bear-like with beautiful hide (fur)

DESCRIPTION: Fur seals are known and named for their thick fur, which has 300,000 hairs per square inch. They were first named "sea bears" by Europeans, similar to their scientific name, which means "bear-like". Pups are born with a black pelt, which becomes dark brown with lighter coloration on the chest and belly. Adult males also have gray hair on the backs of their necks. Males are much larger than females, even at birth. Male pups weigh 12 pounds (5.4 kg) and grow to 385-605 pounds (175-275 kg) and seven feet (2.1 m) in length. Female pups, however, only weigh 10 pounds (4.5 kg) and grow to 66-110 pounds (30-50 kg) and 4.5 feet (1.4 m) in length.

RANGE/HABITAT: The full range of the northern fur seal extends throughout the Pacific rim from Japan to the Channel Islands of California, although the main breeding colonies are in the Pribilof and Commander Islands in the Bering Sea. Smaller rookeries (breeding grounds) exist on the Kuril Islands North of Japan, Robben Island in the Sea of Okhotsk, and on San Miguel Island off Southern California. Northern fur seals live almost all of the time in the open ocean, and only use certain offshore islands for pupping and breeding. They rarely come ashore except during these times, and are almost never seen on mainland beaches unless they are sick.

MATING AND BREEDING: Adult males establish territories in late May to early June, and aggressively guard and herd 40 or more females. Pregnant females arrive at the rookeries in June and give birth two days later. They nurse for about 10 days, then go to sea to feed for four or five days. After that, they feed for eight to ten days and nurse for one to two days. Pups are weaned after about four months on this cycle, which is seen in all otariids. Death rates are high (10-50%) throughout a fur seal's life, but they can live to about 26 years.

BEHAVIOR: Northern fur seals feed on small schooling fish, such as walleye pollock, herring, hake and anchovy, and squid. Although they feed on fish found in the open ocean, they are not deep divers. They usually dive to about 200 feet (68 meters), and their maximum dive depth is about 600 feet (about 200 m). These mammals are pelagic (open ocean) so they cannot always haul out to rest. They have developed a behavior called jug handling, keeping their front and rear flippers out of the water while bobbing on the surface.

STATUS: Once hunted in large numbers for their luxurious pelts (such as those made into coats worn at football games in the 1930s and 1940s), northern fur seals are now protected under the Marine Mammal Protection Act as a depleted species. This means that it is illegal to kill them except for research or native subsistence. The current world population is less than one million, and is declining. Commercial fishing operations may be contributing to the decline, by decreasing availability of fish and entanglement in fishing gear. Also, fur seals are especially sensitive to changes in their environment, as seen in the record numbers of sick or starving fur seals rescued at The Marine Mammal Center during El Niño years.

AT THE MARINE MAMMAL CENTER: In normal years, The Marine Mammal Center admits about five northern fur seals. During El Niño years, this number dramatically increases (22 in 1993, 30 in 1997). This is because northern fur seals are very sensitive to the warming ocean waters of El Niño.

HARBOR SEAL Phoca vitulina meaning of Latin name: calf-like seal

DESCRIPTION: Harbor seals have spotted coats in a variety of shades from silver-gray to black or dark brown. They reach five to six feet (1.7-1.9 m) in length and weigh up to 300

pounds (140 kg). Males are slightly larger than females. They are true or crawling seals, having no external ear flaps. True seals have small flippers and must move on land by flopping along on their bellies. In San Francisco Bay, many harbor seals are fully or partially reddish in color. This may be caused by an accumulation of trace elements such as iron or selenium in the ocean or a change in the hair follicle.

RANGE/HABITAT: Harbor seals are found north of the equator in both the Atlantic and Pacific Oceans. In the northeast Pacific, they range from Alaska to Baja California, Mexico. They favor near-shore coastal waters and are often seen at sandy beaches, mudflats, bays, and estuaries.

MATING AND BREEDING: In California, harbor seal pups are born in March and April and weigh about 30 pounds at birth. If born prematurely, harbor seals retain a whitish lanugo coat (which is usually lost before birth). A pup can swim at birth, and will sometimes ride on its mother's back when tired. Pups make a bleating noise that sounds like "maaaa." After about four weeks, the pups are weaned. Adult females usually mate and give birth every year. They may live 25 to 30 years.

BEHAVIOR: Harbor seals spend about half their time on land and half in water, and they sometimes sleep in the water. They can dive to 1,500 feet (457 m) for up to 40 minutes, although their average dive lasts three to seven minutes and is typically shallow. They are opportunistic feeders, eating sole, flounder, sculpin, hake, cod, herring, octopus, and squid.

While harbor seals swim safely in the surf, they will often curiously watch humans walking on beaches. However, they are wary of people while on land, and will rush into the water if approached too closely or disturbed. In fact, if disturbed too often, they have been known to abandon favorite haul-out sites or their pups.

STATUS: The total harbor seal population in the eastern north Pacific is estimated to be 330,000, and in California the estimated population was 40,000 in 1997. They are usually found in small groups, but sometimes occur in numbers of up to 500.

AT THE MARINE MAMMAL CENTER: From approximately mid-February through the end of June, The Marine Mammal Center's rescue and rehabilitation work is mainly focused around the care of harbor seal and elephant seal pups. Each year people find harbor seal pups on shore and pick them up, thinking the pups have been abandoned. Usually they are not abandoned; the mothers are just out hunting or watching nearby. This problem has caused many seals to be unnecessarily orphaned. These pups are then at further risk because they are unable to get needed antibodies from their mothers' milk, making them more susceptible to diseases. When they are being cared for at The Marine Mammal Center they are kept in an area away from the other animals so they do not catch other diseases. If you see a harbor seal pup alone on a beach, remember to call The Marine Mammal Center at 415. 289.7325 to find out what to do.