- The Washington Times - Wednesday, August 13, 2003

Friendly, playful bottlenose dolphins always have fascinated people, especially since the 1960s TV show “Flipper” made the warm-blooded marine mammals famous.

The average person, however, probably doesn’t realize how much researchers value the creatures, says Dr. Teri Rowles, coordinator of the Marine Mammal Health and Stranding Response Program at the National Oceanic and Atmospheric Administration (NOAA) in Silver Spring.

“It’s pretty amazing the amount of information you can get from one of these animals,” she says. “We use them as sentinels of the marine environment.”

Bottlenose dolphins, large animals with slightly hooked, broad dorsal fins, interest the scientific community for many reasons. They are frequently examined by researchers to simply learn more about the species. In addition, scientists use them to study pollutants and diseases in the ocean. The mammals also have been trained by the U.S. military for wartime procedures.

Dr. Rowles, who is a veterinarian and holds a doctorate in toxicology, says researchers in her department routinely perform necropsies on dead bottlenose dolphins that wash onto beaches. These procedures are similar to human autopsies, where the cause of death, such as infection or cancer, is better analyzed.

During necropsies, scientists try to learn information such as the age of the animal’s sexual maturity, its reproductive condition, what parasites may have infested it and what it has been eating. The creature’s age is determined by counting the growth layers in their teeth.

Although more evaluations need to be completed before a broad spectrum of conclusions can be drawn from the studies, scientists have been able to make some preliminary conjectures.

For instance, it seems the amount of pollutants in male bodies increases with age as they continue to eat contaminated food, while females eliminate pollutants through their milk, which is passed to offspring. The specific pollutants carried by the animals are identified through testing portions of blubber.

Live-capture examinations complement the tests associated with beach strandings, says Aleta Hohn, leader of the cetacean and sea turtle team with the NOAA Research Laboratory in Beaufort, N.C. Ms. Hohn, who holds a doctorate in biology, often works with Dr. Rowles.

“The more we look, the more we find new things about the animals,” Ms. Hohn says. “We’re looking more carefully now than we used to look.”

While examining living animals, technicians record their size and weight. To test for diseases and pollutants, they also take samples of blood, urine, feces and blowholes. For instance, the blood tests reveal which animals carry the antigen for the Moribillivirus that killed a large number of bottlenose dolphins on the East Coast in 1987 and 1988.

Unfortunately, research shows only a small number of dolphins have been previously exposed to the disease. Therefore, if a new outbreak were to occur, there probably would be another mass epidemic.

Researchers also frequently attach tags, which stay intact for about 10 months, to the dorsal fins of the mammals during live-capture examinations, Ms. Hohn says. This allows scientists to track their migration cycles through a satellite system.

For instance, by using the tags, Ms. Hohn followed a herd of bottlenose dolphins from fall 2002 to spring 2003, as the mammals traveled from the coast of Cape May, N.J., to North Carolina and back again. It is hoped that studying these patterns will allow the populations of dolphins along the Atlantic shoreline to be distinguished from one another.

To follow the animals for a longer period, the nicks and notches on their dorsal fins can be photographed, says Randall Wells, a conservation biologist for the Chicago Zoological Society, whose project is based at the Mote Marine Laboratory in Sarasota, Fla. These markings, which are unique to each animal, act as a type of fingerprint.

Mr. Wells, who holds a doctorate in biology, says his department takes about 20,000 pictures of bottlenose dolphins per year. This helps him keep track of more than 2,500 of the creatures. Through his work, he has learned that the animals usually travel in one of three sects — a nursery group with mothers and most recent offspring, juvenile groups and adult males.

“The studies help us know what is required for the animals to survive in the coastal habitats where they are exposed to a great deal of human activity,” he says. “These animals are long-term residents to very specific areas, so they can be impacted by people in those areas.”

For instance, Mr. Wells says he has noted how dolphins’ behavior changes as they are approached by boats. He is concerned about the long-term effect of these actions on the animals, especially because it happens frequently. As of now, he is not sure if it is damaging the animals, but he knows they change their dive and communication patterns when vessels are near.

Although some people have been critical of human interaction with the mammals, such as the Navy’s use of bottlenose dolphins for wartime tactics, animals in the open ocean are free to swim away from anything that bothers them, says Tom LaPuzza, public affairs officer of the Space and Naval Warfare Systems Center in San Diego, a Navy research development and engineering center.

“An animal that works for us has the ability to swim away, but they never do,” he says. “Occasionally, we lose one here or there because they can’t find their way back … but they are very enthusiastic. It’s like seeing your dog running around wanting [you] to throw a bone.”

Mr. LaPuzza says the creatures are taught by certified trainers through repetition to find objects for military officials, such as mines or people. The procedures were designed by Navy scientists who are behavioral psychologists. They have researched many aspects of the animals, including their health, natural sonar, hearing and reproduction.

Since the beginning of the war in Iraq, a team of human divers, unmanned sea vehicles and bottlenose dolphins has found about 235 mine-like objects near the harbor of Umm Qasr, Iraq.

When a bottlenose dolphin finds something resembling a mine, it returns to the handler, and the handler gives the animal an electronic marker, which the animal places near the mine. Then, a diver investigates the situation.

The mammals are especially good at finding items in shallow water that the sonar systems in Navy ships might miss.

The procedure is similar when the creatures find people in the water. Although the animals cannot tell whether people are enemies, they can alert the handler to a person’s location.

“They seem to be incredibly effective,” Mr. LaPuzza says. “They will find exactly what you want. Or they will find something exactly like it that you didn’t know was there. They can do things a diver can’t do. They can dive over and over again with no problem because that’s what they do all the days of their lives.”

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