Dolphins: Our Kin of the Sea
My first personal encounter with a dolphin was at the petting pool of Sea World, San Diego, California, in 1987. I had already read The Dolphins and Me by Donald C. Reed, and had watched nearly every episode of Flipper when the television series appeared on NBC in 1964.
When I attended Michigan State University in the fall of 1970, I considered Marine Biology as a goal for a course of study. Jacques Cousteau had influenced me with his documentaries aired through his The Undersea World of Jacques Cousteau series.
Legends of dolphins rescuing swimmers and protecting them from sharks have always held a place in my heart. Now, here in the 21st century, there are still some people on the planet who are abusing these creatures through malicious killings, some for meat, others for sick pleasure.
This article is my tribute to the dolphin with the hope that all will come to recognize the true value of this wonderful creature.
"Diviner than a dolphin is nothing yet created."
--Oppian of Corycus (169 A.D.)
Dolphins Appear in History
The frescoes in the Palace of Knossos in Crete, Greece, depict dolphins, recording man's encounter with them as early as the 15th century.
Dolphins appear in earlier works of art and sculpture wherever the Greeks had influence, in Knossos, from Palestine and Mesopotamia in the east to Rome in the west, and later throughout the Roman Empire. Even in the rock city of Petra, miles from the sea and hidden in a cleft in the Jordanian desert, there is a carving of a dolphin.
It is from the writings of Ancient Greek poets that we get the tales of Apollo disguising himself as a dolphin, Dionysos turning repentant pirates into dolphins, Arion's and Paros' rescues by dolphins, and Aelian's story of a deep love of a dolphin for a boy.
In Christianity, a dolphin saved the life of Saint Martinian, the hermit who threw himself into the sea to avoid the temptations of a woman (400 AD).
Dolphins in Military Maneuvers
The U.S. Navy Marine Mammal Program (NMMP) trains bottle-nose dolphins and sea lions to help with ship and harbor protection, mine detection and clearance, and equipment recovery.
One team of dolphins is trained to detect and mark the location of tethered sea mines floating off the bottom, while others detect and mark the location of mines on the sea floor or buried in sediment. Dolphins can also swiftly identify mine-free corridors for the initial landing of troops ashore.
How this works is that a dolphin awaits a cue from its handler before starting to search a specific area echolocation. The dolphin reports back to its handler, giving particular responses that indicate whether a mine is detected. The handler then sends the dolphin to mark the location of the object by releasing a buoy, so it can be avoided by Navy vessels or neutralized by Navy divers.
Mine-clearance dolphins were deployed to the Persian Gulf during the Iraq War in 2003. Dolphins effectively detected more than 100 anti-ship mines and underwater booby traps.
Dolphins and sea lions can act as sentries to protect harbor installations and ships against unauthorized human swimmers. Dolphins performed this task during the Vietnam War (1965-1975) and in Bahrain (1986-88). When an enemy diver is detected by a dolphin, the dolphin approaches from behind and bumps a buoy-attached device onto the back of the diver's air tank. The buoy which then floats to the surface and alerts Navy personnel of the intruder. The animals possess superior underwater senses and swimming ability to successfully perform these military-related maneuvers.
The NMMP is scheduled to end in 2017 when robotics will replace the animals.
Typical Makeup of Pods
- a male and female pair
- females and their young
- older and younger males
Social Habits of Dolphins
Dolphins live in pods, which may consist of two to hundreds of dolphins. The larger pods are called "herds" or "schools" and may have more than one species. The Spinner and Spotted dolphins are examples of this type of mixed-species grouping. The two types have different diets, so do not compete for food sources.
Dolphins are extremely social. Relationships, excluding male and female pairs, between dolphins are long lasting.
In their natural environment, they engage in group hunting. The pod also offers protection in numbers. Dolphins have been known to attack sharks and killing them by butting their hard nose into the creatures' gills.
When a pod meets another pod, the dolphins greet each other in a kind of ceremony.
Dolphins are intelligent and enjoy engaging in play. Pod members in the open sea have been seen playing "catch," for example, by tossing seaweed back and forth to one another.
The following video demonstrates the dolphin's ability of self-recognition, something that only animals of higher intelligence do.
Dolphin Behavior: Self Recognition
Another video (below) shows the dolphin's ability to make choices. In other experiments by trainers and persons studying dolphins, our kin of the sea can also create new things and exhibit basic planning skills.
Dolphins' Ability to Choose with Echo Location
- The size of the dolphin brain, relative to its body, is second only to ours.
- Gestation may take anywhere between 11-17 months, depending on the species.
- Calves, the name for newborn dolphins, are generally born tail first.
- Fish and squid are the principals of diet.
- Orcas, also known as "killer whales," are part of the dolphin family.
- Dolphins communicate by frequency modulated whistles, burst-pulsed sounds, and clicks.
- Pod members assist when a dolphin is distressed, indicated by a special whistle.
- Individual dolphins have signature whistles, a sound unique to each.
Hazards to Dolphins
- purse seine, driftnets, gill-nets, and by-catch fishing methods that kill
- potential entanglement in fishing gear
- inhumane captivity
- marine pollution resulting in habitat degradation
- low frequency sonar
- boat and ship traffic
We have a close relationship to all the animals in our world. Dolphins are especially unique in their adaptation to the sea. Their brains function in ways scientists are barely beginning to understand.
When I visited Sea World in San Diego, the trainer entertained the audience with dolphin tricks. I found the animal's ability to recognize geometric symbols and correctly follow a swim path requested by the trainer truly remarkable. At one point, my elder daughter had even considered becoming a dolphin trainer herself. She enjoyed the playful antics of the dolphins that would come up close to her during her body board lessons at Redondo Beach, California.
I secretly dreamed about putting some lady synchronized swimmers together with dolphins for an incredible performance. After doing research for this article, that day-dream doesn't seem all that far-fetched.
Because of this mammal's intelligence, cooperation with man, and joyful nature, we need to pay more attention to its protection and marine environment.
There are many organizations today that are active in the protection of dolphins and other sea mammals.
Sea Shepherd Conservation Society was founded in 1981 and is based in Oregon. Marine life protection is conducted in many cases by direct action. The ship "Sea Shepherd" has made over 200 voyages around the world in its efforts to protect marine life. Particular to dolphin advocacy, the organization has focused against the killing of dolphins in the Faeroe Islands and Japan.
Global Volunteer Network (GVN) has a Dolphin Conservation program along the coast of Kenya for researching the quality of marine life. Dolphins being studied include the bottle-nose, humpback, and spinner species. GVN is endorsed by Bill Gates.
The Oceanic Society has an Adopt-A-Dolphin program that keeps members informed with pictures and news of their chosen dolphin residing in the Bahamas. The Society is based in Ross, California, and does dolphin research and engages in marine ecology and conservation. A $40 membership supports their work.
The MarineBio Conservation Society is based in San Diego, California, and offers year-round learning programs. Informing the public about marine ecology and acting as a coordinator of many marine conservation groups, MarineBio provides listings of U.S. colleges and universities offering degrees in marine biology and oceanography.
Ric O'Barry's Dolphin Project is part the Marine Mammal Project of Earth Island Institute, a non-profit organization founded in 1982. The primary aim of the project is to stop global dolphin slaughter and exploitation. Animal Planet's mini-series Blood Dolphin$ is a film production of this group.
Credits and Resources
http://www.pbs.org/wgbh/pages/frontline/shows/whales/man/myth.html (Dolphins in Mythology)
Photo credit: http://www.ancient.eu.com/image/393/ (The Frescoes at Knossos)
http://www.dolphins-world.com/dolphin-social-structure (Dolphin Social Behavior)