Diving

From mating to sleeping to hunting, dolphins have it covered

Atlantic bottlenose dolphins ride in the wake of a dive boat.
Atlantic bottlenose dolphins ride in the wake of a dive boat.

Our dive boat was cutting tight “donuts” at cruising speed creating waves that any surfer would love.

The surfers riding the waves weren’t the human variety but Atlantic bottlenose dolphins.  

It was hard to tell who was enjoying the experience the most — the dolphins, the scuba divers on the boat or the boat captain with an ear- to- ear grin pushing on the throttle to make ever larger waves.

The boat was filled with the sounds of happy shouts and camera shutters clicking away.

The game ended and we continued on to the dock after another great day of diving with the added bonus of a dolphin experience.

Cool!

Being able to enter into the underwater world and witness the wonders of sea life is what motivates most scuba divers to put on all the gear and jump off the dive boat. The experience gets even better when accommodating dive boat captains are on the look-out for opportunities for divers to observe amazing sights, like the Atlantic bottlenose dolphins, on the way to and from a dive site.

Bottlenose dolphins are famous and loveable. They are popular exhibits at public aquariums and sea park attractions. If you are old enough, you undoubtedly remember the 1960s “Flipper” movies and TV shows. If not, you are sure to have seen or heard stories about dolphins including the accounts (real or imagined) of dolphins saving swimmers or capsized boaters.

Visitors to the Florida Keys, besides seeing them in the ocean, have a wide variety of opportunities to see or to get up-close-and-personal with dolphins at locations from Key Largo south towards Key West.

 The terms "dolphin," "dolphinfish" or "mahi-mahi" are also used to refer to a  very popular game fish with a blunt, flat forehead and body colors of gold, blue, green, white and yellow. So, if you see dolphin on the menu, don’t worry — you aren’t about to eat “Flipper.

People use the terms dolphins, porpoises and whales to describe marine mammals belonging to the order Cetacea (from the Greek work ketos, “large sea creature”). The orca or killer whale is the largest member of the dolphin family.

 Dolphins and porpoises are sometimes confused. Dolphins tend to have prominent, elongated “beaks” and cone-shaped teeth, while porpoises have smaller mouths and spade-shaped teeth.

The dolphin’s hooked or curved dorsal fin (the one in the middle of the animal’s back) also differs from the porpoise’s triangular dorsal fin. Most scientists agree that there are 32 dolphin species and only six porpoise species found in temperate and tropical waters around the world.

Dolphins are mammals — just like you and me. They are warm blooded, give live birth, nurse their babies and, at least for a short time, have hair. A baby dolphin is born with whiskers — on its upper jaw (rostrum) — that fall out soon after birth. Female dolphins are called cows, males are called bulls and young dolphins are called calves.

Dolphins live about 40-50 years, with a lifespan of 40-45 years for males and more than 50 years for females. Males grow to lengths from 6.0 to 12.5 feet, with males slightly larger than females. Adults weight from 300-1400 pounds.

Sexual maturity varies by population and ranges from 5-13 years for females and 9-14 years for males. Calves are born after a 12 month gestation period and are weaned at 18 to 20 months. Calving occurs every 3 to 6 years. Females as old as 45 years have given birth.

Turns out that dolphins are, well there is no other way to say it, promiscuous. A pair of dolphins usually engages in mating for a few days, but then the male goes on to mate with other females.  And, just like humans, dolphins have sex for other reasons than reproduction. If food is scarce they may not mate at.

Bottlenose Dolphins have 72-104 teeth. They only get one set of teeth for life. Dolphins use their teeth to catch food and then they swallow it whole.

They use several hunting strategies, including "fish whacking," where they strike a fish with their flukes and knock it out of the water.

Bottlenose dolphins have excellent vision both above and below the water. They produce an oily substance to protect their eyes and help them see underwater. Dolphins can see well at night.

Dolphins also have excellent hearing and use echolocation (biological sonar) for finding the exact location of objects. The “melon” shape of the top front of their head helps transmit the “sonar.”

Some people say they can feel the buzz from dolphin echolocation when the people are in the water. Biologists say dolphins can even determine if a person has a metal implant and will, in dolphin water parks, swim by to check-out a person with an implant.

Dolphins need to be conscious to breathe or they will suffocate.

What about sleep? Dolphins have solved this problem by letting one half of their brain sleep at a time. Wish I know this trick going through boring classes in college.

Threats to dolphins include: injury and death from fishing gear, such as gillnet, seine, trawl, and longline commercial and recreational operations; exposure to pollutants and bio-toxins; viral outbreaks; and harvesting in Japan and Taiwan.

Feeding wild dolphins is illegal and can result in a significant fine.

After living four years in the Upper Keys, my wife and I decided it was time to have a dolphin experience and visited the Dolphinsplus bayside facility in Key Largo.

Dolphinsplus, which offers research, animal care and veterinary internships, has been in Key Largo for 35 years. It now has locations on both the bay and ocean sides of the Overseas Highway.

Dolphinsplus, which pioneered the swim with dolphin experience in 1980, is a research and education facility that plans to have 30 of its projects peer reviewed (reviewed by other experts) and published this year. One of its programs is recreational therapy for special needs children.

The organization is heavily involved in the community and is in the process of helping to raise funds for musical instruments for school aged kids.

It operates the not-for-profit organization, Dolphins Plus Marine Mammal Responder, which responds to stranded dolphins and whales for all of Monroe County. While I was interviewing Art Cooper, vice president/director of operations for Dolphinsplus, received a call to respond to two whales stranded at the base of the Seven Mile Bridge.

During our visit to the bayside facility my wife and I were given an informative briefing on bottlenose dolphins, fitted with life vests and then went to the water to interact with the dolphins — a memorable experience that gave me a new Facebook profile image and some great information for this story.

For more on Bottlenose Dolphins see: http://www.nmfs.noaa.gov/pr/species/mammals/dolphins/bottlenose-dolphin.html

For information on Dolphinsplus see: http://www.dolphinsplus.com/

Don Rhodes, in addition to a career in government affairs, has taught scuba for 29 years. He and his wife retired to Tavernier four years ago, where he works as an instructor for Conch Republic Divers .

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