Wednesday, February 19, 2020

Dolphin Dangers: What’s in the Water?

Stepping Stones


Photos by Bob McConville | Parton will bear a scar around the eye and back but survived a shark attack.

s there anything more pleasant in life than to be by the water, or on a boat, and have a dolphin come by, look at you and give you that sweet little smile that we always long to see? Life in a dolphin’s world seems so simple; they feed, they play and they rest. What could go wrong with a lifestyle like that? Unfortunately, the answer is that plenty of things could cause them problems.

Starting right at birth, dangers abound for these small calves. In addition to providing milk and teaching the young of year how to survive, the mothers must remain ever vigilant against the enemies and threats that constantly surround them. Let’s look at a few of these obstacles that befall the baby dolphins.

Because they are so small at birth, about 2-3 feet long and 25-30 pounds, they are an ideal meal for several area predators. In the waters surrounding Marco Island, there is a population of shark species. Most worrisome for the young dolphins are bull sharks and hammerheads. Babies are not very fast or agile when they are young so they would be a prime target for the above-mentioned predators.

Throughout the last 13 years of studying the local dolphin population, the research team on board the Dolphin Explorer has catalogued many births, only to have a small percentage of those newborn disappear. Most likely, a shark took advantage of the lack of swimming skills of a youngster, costing it its life.

Mothers are fierce competitors in trying to protect their young, but the battle is not always successful. Sometimes a group of dolphins will surround a calf in hopes of deterring an attack as well, trying to keep the youngster safe.

Sometimes the battle is won. We have two dolphins that are shark bite survivors. Parton is now three years old and survived an attack about 1½ years ago, sustaining wounds on the back and around the right eye. Skipper was bitten at eight months old in the stomach area and is now six years old. Both will carry scars for life but are doing well.

There is another danger to calves and, surprisingly to many, it comes from their own kind. Several eyewitness events have captured aggressive male dolphins attacking newborn. It is called “infanticide” and is probably more common than we would like to believe. Events have been filmed of a female giving birth and, almost immediately, two males began an assault on the calf. In spite of the mother’s best efforts to protect the baby, the aggression of both males was too powerful for her to fight.

A tour guide on the south end of Marco Island actually witnessed this not too long ago. The mother tried to keep the calf against the roots of a mangrove island, using her own body as a shield against the aggressing male. Unfortunately, the male was successful in its endeavor.

During the week of November 4th our team witnessed an adult female named Rangle with a new calf. By the weekend this female was being stalked by two males and no calf was in sight. It is suspected that they may have eliminated the baby in order to mate with the female. There was another female in our area that we thought would be giving birth this fall. Although no new calf was ever seen with the female, these same two males followed her for several weeks, exactly as they are following Rangle now.

Skipper, bitten by a Bull Shark in the midsection at 8 months old, is now 6 years old and doing well. Others were not so lucky.

There are other dangers to dolphins of all ages as well. Just a few years ago, Red Tide was the reported cause of death of more than 200 dolphins from northern Collier County all the way up to Tampa. This is not the first such event recorded like this, with the deadly toxin taking a toll on hundreds of other dolphins in the past several decades.

Lastly, the other danger to dolphins is man. Too often, small boats travelling fast in shallow waters might strike a dolphin causing life-ending injuries. Even the curious tourist tossing a shrimp or a fish from a boat doesn’t realize the habits that can be formed by feeding these mammals. They could be on the lookout for an easy meal from other boaters. This, too, has cost dolphins their lives. They stop doing what comes naturally and depend on an easier source of food.

Recently a dolphin following a fishing boat was speared because of this activity and the boater is facing a felony charge for killing a protected species. The Marine Mammal Protection Act prohibits feeding of dolphins and it is a serious offense.

So the next time you see a dolphin, with that special smile meant just for you, remember that life is not as simple as feeding, playing and resting. They, too, must deal with the dangerous side of life.

Bob is a Naturalist on board the dolphin study vessel Dolphin Explorer. He is the author of two books, available locally, and an award winning columnist for this newspaper. In addition to his love for nature, Bob loves his wife VERY MUCH!

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