DOLPHINS AND HUMANS
Flipper and Luke Halpin in 1963 Plutarch once said the dolphin is "the only creature who loves man for his own sake." Around 50 to 100 dolphins come to meet humans and play with them in a section of the open ocean off of the Bahamas and the swim into shore to meet bathers at Monkey Mia in Australia.
Dolphin sometimes seek out surfers and scuba divers to play with. Such contacts have been reported in Greece, New Zealand, Bahamas and Australia. Spotted dolphins off of the island of San Salvador in the Bahamas have played with divers and even pulled their hair and gently mouthed their arm "like a puppy." Some dolphins that have had their pens cut open by animal rights activists have preferred to stay in captivity with humans than escape to the open sea. ⊗
According to the Egyptian newspaper Al-Masa, a dolphin in the Mediterranean Sea retrieved the body of a truck drier who had drowned and carried his body to a beach near Port Said. The man had drowned while swimming and divers and police had been unable to locate the body.
The Flipper television series, which ran during the 1960s, is credited with making dolphins popular. The show was shot at several locations, including Nassau in the Bahamas. There was a real Flipper and several stand ins that would take his place at different locations. After the show ended the dolphins were deposited in small metal tanks. Kathy, a dolphin that appeared in the show for several years, reportedly "committed suicide" out of loneliness. Heartbroken by what happened to the former Flippers, one of their trainers,Ric O'Barry became an advocate for dolphin rights and made it his goal to free dolphins kept in inhuman conditions. He has been very active trying to prevent the slaughter of dolphins in Japan.
Websites and Resources: National Oceanic and Atmospheric Administration noaa.gov/ocean ; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Ocean World oceanworld.tamu.edu ; Woods Hole Oceanographic Institute whoi.edu ; Cousteau Society cousteau.org ; Montery Bay Aquarium montereybayaquarium.org
Websites and Resources on Fish and Marine Life: MarineBio marinebio.org/oceans/creatures ; Census of Marine Life
coml.org/image-gallery ; Marine Life Images marinelifeimages.com/photostore/index ; Marine Species Gallery scuba-equipment-usa.com/marine
Dolphins, Myths and Human History
Greek and Roman legends describe dolphins helping shipwrecked sailors and playing with children. According to the ancient Greeks dolphins were originally pirates that made the mistake of kidnaping Dionysus, the god of wine. To punish the kidnapers for their deed Dionysus turned their ship sails into grape vines. When the pirates leaped into the water they turned into dolphins.┵
Pliny the Elder wrote about a dolphin that fell in love with a boy. The boy used to call for the dolphin on his way to school in Pozzouli and feed his friend fish from his hand. The dolphin used to let the boy ride on his back across the bay. One day the boy died. After repeatedly coming to the meeting place on the bay and not finding the boy there the dolphin passed away "undoubtably from longing," Plin said. ┵
Stories about dolphins helping shipwrecked sailor and purposely driving away sharks are largely regarded as myths. Sharks and dolphins are natural enemies and the presence of dolphins sometimes keeps sharks away. Dolphins "helping" sailors are more acts of curiosity than benevolence. Some scientists theorize they play with humans the same way they would with a piece of debris or another sea creature.
Swimming with Dolphins and Dolphin Therapy
In recent years petting and swimming sessions with captive dolphins have become popular all over the world. Visitors pay up to several hundred to pet and hang out with dolphins kept in tanks and pools at ocean parks or luxury hotels. Trained dolphins cost about $70,000. Untrained one can be purchased from fishermen for about $7,000.
Tickets often sell for $50 or more and often sell out. For that money tourists often expect a dorsal fin ride and maybe a double foot push, which is a bit like waterskiing. Captive dolphin petting sessions are generally regarded as safe. The dolphins are usually well trained and they are handled by professional trainers. Sometimes injuries occur. One woman in Japan was struck in the chest by a dolphin, breaking here ribs and a bone in her back.
Dolphin therapy describes a treatment in which people suffering depression and other mental illnesses spend time with dolphins. One study found that patients who took part in such a program with bottlenose dolphins for two weeks experienced relief from their symptoms while patients in control group that spent time in the water and sun without dolphins dd not enjoy the same benefits.
In some places tour groups sponsor swims in the open sea with wild dolphins. Describing a dolphin encounter in the Bahamas," Kenneth Norris wrote in National Geographic, “When...I entered the water, about a dozen dolphins swam right over to us. They circled, pirouetted around and under us, gave us a pump or two with their flukes, and glided off into the blue like sail planes four times faster than we could go. There was no doubt the dolphins came to play. The speckled-bellied juveniles came most often, waiting graciously for us to do something mildly exciting.”┺
Aggressive Dolphins and Negative Side of Swimming with Dolphins
Atlantic white-sided dolphin Conservationists oppose the swim-with dolphins programs, saying they are stressful to the animals. The industry is unregulated. Some of the dolphins are kept in depressingly small tanks and given little rest by trainers who have bought the dolphins for as little as $800 on the black market and have little interest in anything but making money. Outrage reached a high point after one dolphin died at a marine park in Mexico. An autopsy revealed extensive stomach ulcers. In 1968, two captive dolphins killed themselves by swimming full speed into walls in their tank.
Dolphins are caught with several boats that surround a small herd with nets and gradually move in on the dolphins. Some dolphins injure themselves when they panic and struggle and try to get away. Some go into shock. Around 30 percent of those captured die within the first two years. Survivors live into their 30s and 40s.
Pacific white-sided dolphin Swimming with wild dolphins in the open sea can have a negative side. In the United States, the Federal Marine Mammal Protection Act bans “harassing” dolphins, which means pursuing or annoying them to the point that it hurts them or changes their behavior. Violators face a $20,000 fine. Trevor Spradlin, a biologist with the National Marine Fisheries Services, says swimmers should stay at least 50 feet away from dolphins and use binoculars to get a closer look. An American ban on feeding wild dolphins is routinely ignored.
Not all dolphins are friendly. There have been numerous reports of people bitten, bumped and prodded by dolphins. People have even been pulled underwater by them. One woman told the New York Times she feed some dolphins and then jumped in the water to swim with them and was attacked by a dolphin. She said, "I literally ripped my left leg out of its mouth. She had to spend a week in the hospital recovering.
Commenting on reports of an increase in dolphin-related injured to people, Dr. Amy Samuels of Woods Hole Institute said, "Just because dolphins have a smile doesn't mean they're nonaggressive." Dr. Andrew Reed of Duke University's Marine Laboratory told the New York Times, dolphins "are big, wild animals. And people should respect them as such."
Trained Dolphins and the U.S. Military
U.S. Navy Marine Mammal Program In the 1960s, the U.S. Navy Marine Mammal Program in San Diego switched from studying dolphin’s swimming and acoustic ability to investigating their potential as vehicles of war. The Navy also studied sea lions, beluga whales and other marine animals. [Source: Tony Perry, Los Angeles Times, April 2007; Dwight Holing, Discover, October 1988]
The dolphins were trained to respond to acoustic signals, such as the noise made by a toy cricket clicker, and they were give rewards of fish as positive reinforcement. Described as "marine operational systems," they performed best at retrieval tasks and identifying mines but were also taught to pull regulators from the mouths of divers and deploy bombs.
Dolphin sonar is considered better than anything used in the military. Trained dolphin can locate mines from a distance of several hundred meters with 100 percent accuracy. On several occasions the Navy has said it would develop technology to make the use of dolphins obsolete but thus far it has been unable to achieve this goal. In the late 1990s the U.S. government gave one group several million dollars to develop an electronic mine-detecting robot dolphin. The project proved to be too difficult and was dropped.
The Navy denies that dolphins have been trained to carry explosives to blow up enemy vessels or kill anyone. They also say there is no truth to the claim that dolphins were trained to kill enemy frogmen with hollow lances worn over their beaks during the Vietnam War.
A half dozen dolphins were sent to Vietnam to protect Cam Rahn Bay and locate potential saboteurs during the Vietnam War. Five dolphins with a 25-man support team were sent the Persian Gulf during the Iran-Iraq war in the 1980s. In 1996, dolphins guarded the bay next to the San Diego Convention Center during the Republican convention. Soviet intelligence once claimed the CIA planed to use dolphins to assassinate Fidel Castro.
The nefarious capabilities of dolphins was highlighted in the 1973 sci-fi thrilled Day of The Dolphin with George C. Scott. In the film evil corporate executives kidnap two talking dolphins and enlist them in a plan to assassinate the U.S. president by plowing up his yacht.
Current Status of Trained Dolphins and the U.S. Military
U.S. Navy Marine Mammal Program As of 2007, there were 74 dolphins at the U.S. Navy facility at Point Loma, California, which also has 25 California sea lions (a Navy beluga whale is kept nearby at SeaWorld). With the end of the Cold War, the number of dolphins in the program was reduced from 95 to 75 and the "excess" dolphins were sold to theme parks in Florida and the Bahamas.
Dolphins outfit with cameras on their flippers were mobilized as minesweepers for the war in Iraq from 2003 to 2005. The dolphins along with some sea lions were sent to the Persian Gulf in advance of the U.S. invasion of Iraq. At that time dolphin lovers sent a protest petition to the U.S. Department of Defense stating: “No member of a civilized society should condone the abuse and exploitation of dolphins for military purposes.”
A 1990 presidential panel declared that dolphins were definitely non-combatants. The statements were made after rumors were spread, as they had in the past, that dolphins were being trained to use explosives, attack enemy ships and drag underwater terrorists to their deaths. When Hurricane Katrina hit the southeast United States, a British newspaper reported that Navy killer dolphins had gotten loose in the Gulf of Mexico. In response to this and other similar assertions, the U.S. Navy website states: “The Navy does not now train, nor has it ever trained its marine mammals to harm or injure humans in any fashion or to carry weapons to destroy ships.”
The controversy over the military applications of dolphins was back in the news in 2007 when it was announced that dolphins and sea lions were being considered for use as guards at the Kitsap-Bangor Naval Base in Washington, home to the U.S.’s largest nuclear arsenal. The plan called for 30 dolphin and sea lions working in shifts---primarily at night when humans, even with detection equipment, tend be less effective---to guard the base, where Trident submarines are based. Conservationists opposed the plan, claiming among other things that the cold water around the base harmed the dolphins, an assertion the Navy refuted.
The dolphins working outside Kitsap-Bangor have a special device outfit on their snouts. When they encounter a swimmer they releases a flashing beacon on the surface which alerts security teams to the location of the swimmer. Dolphins and sea lions are are also on duty in waters off the submarine base in Kings Bay, Georgia. Among them is Toad, who is in her late 40s and served in Vietnam. Some aspects of the Navy dolphin and sea lion program remain secret such as the hearing and vison capabilities of the animals and how many soldiers accompany them to provide “force protection.”
Trained Dolphins and the Soviet Military
U.S. Navy Marine Mammal Program The Kazachya naval base in Sevastopol, Ukraine had facilities for a special unit of 70 "killer dolphins" that had been trained to "seek, find and kill" frogmen, and sniff out mines and torpedoes and attach a special glue to metal ships that enabled navy personnel to blow the ships up. [Source: Richard Paddock, Los Angeles Times, October 9, 2000]
The dolphins reportedly were taught to kill divers by a attaching a cigarette-box-size device that injected a lethal dose of carbon dioxide and were dropped from helicopters and planes with parachutes. They were used to locate sunken vessels, submarines and crashed planes. Some reportedly were killed in kamikaze missions with explosive strapped to their backs.
With the collapse of Communism, the killer dolphin detachment suddenly found itself without funding and a mission. Attempts to persuade oil companies to take the dolphins were unsuccessful. As of the early 2000s, scientists were promoting dolphin therapy, charging $10 per session and promising to cure a wide range of ailments with their "natural ultrasound" and ability to improve people's auras. In most sessions people swim around with the dolphins in an outdoor pen with oil tanks and rusted naval ships nearby.
Kazachya also makes money with a dolphins show and charging money for pictures painted by dolphins (apparently painting for a dolphin is not all that different than disarming a mine). Some of the dolphins have been contracted out to dolphin shows in Cyprus, Saudi Arabia, the United Arab Emirates, Russia and other parts of the parts of the Ukraine. The dolphins have also been trained to work on offshore oil rigs, locate accident victims at sea and do underwater exploration for geological surveys.
Dolphin fishing Dolphins are vulnerable to toxic pollutants. They store food energy in their blubber, where toxins also tend to accumulate. Dolphins are fine except when they have to draw food from their blubber, causing the the toxins to circulate through their system in extremely high doses.┺
Spotted dolphin and eastern spinner dolphin populations are only a fraction of their historical numbers. Of the six porpoise species the two that live in open oceans---and thus have the least exposure to gill nets---are faring much better than their shallow-water relatives. Populations of Dall’s porpoise (Phocoenoides dalli) in the North Pacific and the spectacled porpoise (Phocoena dioptrica) in the Southern Ocean are in relatively good shape. On the Yangtze River in China, an endemic population of finless porpoise (Neophocoena phocoenoides), the world’s only freshwater porpoise population, is in steep decline. The causes? Unmanaged fishing and rampant development on the river. The marine populations of finless porpoise are somewhat better off, depending on how much fishing is done in their home waters. The message is clear: if there’s a net in the water, a porpoise will find it.
There have been problems with dolphins beaching themselves like whales. In March 2005, a pod of rough-toothed dolphins beached themselves in the Florida Keys near where the U.S. Navy was using sonar in military exercises, At least 23 of 70 dolphins died, after they became stranded at Marathon key. Some speculate that the normally deepwater dolphins could have become disoriented from decompression after sonar made them surface too quickly.
Hunted dolphins in the Faroe islands As an explanation of why heavily fished tuna survive better than dolphins a single tuna with a ten year life span may produce two million eggs each spawning season, while female dolphin may have a dozen offspring in her 35 year life.┺
Dolphins in Japan, The Cove See Separate article
Threatened Dolphins and Fishing Nets
Sonar may cause causes a decompression sickness in dolphins like it does with whales. See Whales.
In the late 1980s it was estimated that over a million dolphins a year were being killed by fisherman trying to catch tuna, squid and other food fish. Most of the dolphins died by getting entangled in drift nets up to 40 miles long or encircled by purse seine nets, used to capture schools of tuna.
Hunted dolphins in the Faroe islands Tuna fishermen have traditionally looked for schools of dolphins because yellowfin tuna tend to congregate underneath them. Scientists speculate the tuna do this because the dolphins protect them from predators and help them locate food. The confusion of being trapped in a seine net often forces the school of dolphins to sink to the bottom of the net in a helpless pile. Dolphins could easily prevent themselves from being trapped by purse string nets that they could easily jump over but they don’t. Fortunately drift nets are no longer used and techniques have devised to drive the dolphins from the seine nets without affecting the tuna catch.┺
Changes introduced in U.S. fisheries in the 1990s reduced the numbers of dolphins accidently caught by a third. The United States introduced the dolphin-safe label which placed on cans of tuna in which tuna were caught using methods that minimized the harm to dolphins. Starkist, Chicken of the Sea and Bumble Bee all went along. In 2002, the Bush administration changed the definition of dolphin-safe to allow the encircling of dolphins to catch tuna in the name of free trade and globalization and a concession to the Mexican fishermen who want access to the American market.
In the mid 2000s it was estimated that 300,00 dolphins, porpoises and whales were still being killed by fishing nets each year, with dolphins in the Philippines, India and Thailand being under the greatest threat. Many of those killed in the open sea are killed by gill nets. Deaths can be reduced by using simple, low cost safety measures such as making slight modifications to fishing gear.
Researchers Find Beached Dolphins are Often Deaf
Dead Risso's dolphin
on Norwick Beach David A. Fahrenthold wrote in the Washington Post,”New research into the cause of dolphin "strandings" - incidents in which weakened or dead dolphins are found near shore - has shown that in some species, many stranded creatures share the same problem. They are nearly deaf, in a world where hearing can be as valuable as sight. That understanding - gained from a study of dolphins' brain activity - could help explain why such intelligent animals do something so seemingly dumb. Unable to use sound to find food or family members, dolphins can wind up weak and disoriented. [Source: David A. Fahrenthold, Washington Post, November 15, 2010]
Researchers are unsure what is causing the hearing loss: It might be old age, birth defects or a cacophony of man-made noise in the ocean, including Navy sonar, which has been associated with some marine mammal strandings in recent years. The study, published Nov. 3 in the journal PLoS One, examined several species of marine mammals - including dolphins and small whales - in the Gulf of Mexico, Atlantic Ocean and Caribbean Sea. The animals had been found stranded in the wild and taken in for medical treatment and feeding.
Each year, 1,200 to 1,600 whales and dolphins are found stranded off the U.S. coast, according to the National Oceanic and Atmospheric Administration. Most are dead: In 2007, the most recent year with data, 195 out of 1,263 animals were found alive. But many are euthanized on the scene or die later. Others survive but are too young or too debilitated to be returned to the wild. Of the 195 animals found alive that year, five were released.
Washed up dolphin at Eskmeal Trying to study what put these animals in distress, the researchers faced a puzzle. How do test a dolphin's hearing? "They can't raise their flipper" if they hear a tone, Mann said. Instead, researchers looked for reactions to the sound inside the animals' brains. The researchers affixed sensors to the creatures' heads with suction cups, which could detect electrical activity in the brain. They then played a series of tones: If the animals could hear them, the sensors would detect millions of neurons firing to process the sound.
In some of the species they studied, the tests showed that stranded animals could still hear normally. Three Risso's dolphins, two pygmy killer whales and a spinner dolphin showed no problems. But the researchers found severe to near-total hearing loss in two species. Among bottlenose dolphins, four out of seven stranded animals had hearing problems. Among rough-toothed dolphins, the total was five out of 14. That, they said, could be a serious problem for animals that live in often-murky waters. "These animals are living in an environment where vision can't play the same role it does on land," said Randall Wells, a senior conservation scientist at the Chicago Zoological Society who was another of the study's authors. "Sound is probably the most important sense that they have."
What Caused the Dolphins to Go Deaf
David A. Fahrenthold wrote in the Washington Post, “Without the ability to hear these sounds, scientists said dolphins can be helpless. In some cases, the animals had lost more than 99 percent of their echo-locating capacity: If a normal animal could detect prey at 100 yards, these dolphins could do it only at a yard or less. [Source: David A. Fahrenthold, Washington Post, November 15, 2010]
The research did not indicate what might have caused the animals to lose their hearing. Mann said he thinks the problem is most likely a combination of old age, birth defects and disease. But other researchers have also identified a contentious and growing issue: too much noise in the ocean. Dolphins evolved when the only source of loud sounds underwater would have been thunderstorms or unusual events such as volcanic eruptions.
Now, however, there are the sounds of powerboats and huge oceangoing ships. Oil and gas exploration efforts use loud noises to conduct seismic tests of the seabed. Navy exercises fill the water with the sounds of explosions and sonar. In Sarasota Bay, Fla., home to about 160 dolphins, researchers have calculated that a powerboat passes within 100 yards of every dolphin every six minutes.
"These animals that are very finely tuned acoustic machines are now having . . . to deal with noises, with sounds that their ancestors never knew," Wells said. He said it's possible, but not certain, that chronic noise played a role in damaging some dolphins' hearing.
Scientists study dolphins by observing them in the wild, performing experiments and tests with captive dolphins, periodically taking wild dolphins from the water to take measurements, and doing analysis of their DNA.
In the 1960s scientist Dr. John C. Lilly released all of the dolphins he been attempting to teach English to because he "no longer wanted to run a concentration camp for my friends,"⊗
Fuji, a dolphin at a marine park in Okinawa, lost must of his tail to a strange disease. Enough of the tail for a rubber prosthesis designed by sculptor Kazukiko Yakushiji to be affixed with plastic reinforcements and metal screws. With her new tail she was able to do tricks at the marine park like other dolphins.
Image Sources: 1) Wikimedia Commons 2) NOAA
Text Sources: Mostly National Geographic articles. Also the New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
© 2009 Jeffrey Hays
Last updated March 2011