Photo by Wendy Wilson Billiot
This baby dolphin, named Cayenne, was trapped in a borrow canal not far from the author’s bayou home. She was later transported to Marine Life in Gulfport, Mississippi. She was removed from the center before Hurricane Katrina; upon her return, Cayenne contracted a fungal infection that caused her death.
Those of a particular generation acquired their first and only knowledge of dolphins through Flipper, the mid-1960s TV series about a precocious dolphin and its relationship with an adolescent boy. In the series, Flipper exhibited high intelligence and an extraordinary understanding of human motives, behavior, and vocabulary. This trained dolphin’s abilities, we now know, reflected the startling intelligence of the species.
Among other locales, bottlenose dolphins inhabit the warm waters of the Gulf of Mexico, where they comprise about thirty percent of the total population of bottlenose dolphins in U.S. waters. (Often, bottlenose dolphins are referred to as porpoises, but there are no true porpoises residing in the Gulf of Mexico.) Members of the whale family, bottlenose dolphins are just one of thirty-two species of dolphin. Warm-blooded marine mammals, they breathe via lungs, bear live young, and nurse them. Sound familiar? The parallels do not stop there.
Like humans, dolphins exhibit a social structure that reflects the old adage “safety in numbers.” These sleek marine mammals travel in groups, called pods, which offer them protection from larger predators and make them more efficient hunters. But dolphins are also protected by laws. The Marine Mammal Protection Act of 1972 makes it illegal to disturb wild dolphins at any time. It is against these protective laws to hunt, harass, capture, kill, or collect these creatures; and doing so carries fines of up to $25,000 and imprisonment of up to one year. They can, however, be watched from a distance of at least 150 feet; and the easiest place to observe dolphins in their natural habitat along the Louisiana coast is from the sandy beaches of Grand Isle.
In these shallow, salty waters, dolphin pods feed and frolic, putting on a veritable sea show free of charge. Adult and juvenile dolphins seem to play chase, swimming to and fro, slapping their tails on the surface of the water, and leaping out of the waves. But no matter the amount of play, they always stick together.
One way they accomplish this is by means of echolocation, or sonar, which enables them to sense their proximity to one another as well as to other objects. This ability is aided by a fatty deposit called a melon, located between the skull and the blowhole. The melon directs and focuses dolphins’ communications, which sound like clicks to us. Although they have excellent eyesight, turbidity of the water prevents dependency on eyesight alone.
Another way the pods stay together is through the use of distinctive whistles. Each dolphin creates a whistle that researchers believe is an identifier, like a name. For example, when a calf gets separated from its mother, either or both dolphins repeat the whistle until they rejoin. In times of distress, the whistle is louder and frantic, analogous to a human scream. Their whistles also serve another vital purpose: ringing the dinner bell.
When a pod locates a food source, the whistles of its members call other pod-mates to assist in rounding up schools of fish for consumption. But it’s not always a free-for-all—they share. Once the pod circles and entraps a school of fish, members take turns swimming into the center of the ring, consuming their portion of the fish.
To further confirm that dolphins are social animals, researchers have observed them rubbing pectoral fins, as though in a handshake. They’ve been observed swimming side by side, resting fins on one another, as in a gentle caress. And like all social creatures, they have their squabbles, as indicated by the direction from which they approach each other. A friendly approach comes from behind or from an oblique angle. An aggressive approach would be displayed by either a direct or perpendicular approach.
Ever curious, dolphins may approach a boat and can be observed swimming at great speeds alongside cruise ships or yachts. They may approach smaller fishing boats, too, coming within just a few feet, surfacing, taking a look, submerging, and resurfacing several times as though checking out the boat and its occupants. A boater in this situation must remember not to feed, touch, or in any other way interact with them. The best advice is to wait until the dolphins satisfy their curiosity and depart. Otherwise, the boater must very slowly and carefully motor away from the pod, thereby adhering to the 150-foot distance requirement.
The 2010 BP oil spill, which spewed two hundred million gallons of crude oil into the Gulf of Mexico, caused great concern over the future of the local Atlantic bottlenose dolphin population. After studying dolphins living in Barataria Bay, researchers found many underweight and anemic dolphins, with some showing signs of liver and lung disease as well as other health issues. According to a 2016 study by the National Oceanic and Atmospheric Administration, there are still higher-than-average strandings of dolphins and whales along the Gulf Coast (which happens when they are sick or dying) each month than before the spill.
If dolphins of the Louisiana coast are as resilient as their human counterparts, they will make a full comeback; and these intelligent, playful marine mammals will grace our Gulf coast for many years to come.