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wild dolphins

Florida’s Wild Dolphins Reveal Unique Social Feeding Behavior

For the last decade, the Taras Oceanographic Foundation, under a general authority of the National Marine Fisheries Service, has been conducting dolphin surveys in Palm Beach County. We position or boat within three miles from shore, and travel at slow speed, until we see dolphins. We will then follow the dolphins long enough to photograph each dolphin and document their behavior. And although we have studied wild dolphins for decades, we still find new and different behaviors that are remarkable.

There are days when bait fish seem to fall fro m the sky. On those special days, when the seas are flat, we watch all kin ds of fish jumping out of the water; some high in the air in a single arc, others low and repeatedly as they travel some distance. Flying fish routinely glide, with ease, for several meters. Ballyhoo and Bonita will jump to avoid being eaten. Every once in a while, a clever dolphin will take advantage of these jumping fish; a clever dolphin like Odyssey, and her offspring.
Odyssey was conducting a master class in the art of catching fish. And when I say ‘catching fish’ I mean CATCHING fish. She was throwing a fish into the air, and artfully catching with in her mouth. She demonstrated the process a few times for her calf, and then did something remarkable.

She bit off the head of the fish, before throwing the body in the air, for her calf to catch. We could not help but make the comparison of a mother cutting the crust off a sandwich, before serving it to her child. But it is more than that; she was keeping her calf safe.
For the significance of this simple act, we need to first ex­ amine the basic anatomy of a fish. Fish use gills to acquire oxygen from the water. These gills are located just at the base of the head. When a fish breathes, it draws in a mouthful of water and pulls the sides of its throat together, forcing the water through the gill openings, which expand away from the body.

Dolphins do not chew their food. It is imperative, therefore, for a dolphin to swallow their prey, head first. If a fish were eaten tail first, it might expand its gills while passing through the throat of the dolphin and become wedged. In all the necropsies I performed, I once found one dolphin with a fish caught in its throat. The fish was swallow ed tail first, and the res ult was deadly. Back to Odyssey and her calf.
She was biting the heads off the fish, so her calf would not catch the fish backwards and choke to death. She threw the fish body high in the air, and her calf made repeated attempts to make the catch. More likely motivated by the game than the food, the small dolphin was still nursing and probably not too hungry. Over the next few months, as this calf grows, Odyssey will insist it hunt down its own food. The catching strategies learned now, will be all the more important in the future.

But even the best strategies and the most prepared youngster will not grow to be an adult unless there continues to be the abundance and variety of fish to eat. We are currently living through the sixth mass extinction event this planet has experienced. ln the past, these epic occurrences were the result of volcanic eruptions or asteroids striking the earth, but this time they are our own doing.

Why is it important to study dolphins? Sure they are cute and all, but why should anyone support such endeavors? Because in many ways, we are alike. Dolphins eat the fish we eat. They raise their kids to be better citizens and work every day to make a living and support their families. They are the masters of the ocean environment; a subject about which we are remarkably naive. And the ocean is vital to the survival of us both.

Although we continue to harvest the resources the oceans provide, at unsustainable rates, we could learn from the marine mammals how to find areas of highest productivity and hunt selectively. As we increase the noise in the ocean with our recreational watercraft, commercial ships and military exercises, we learn from the dolphins that in the deep ocean, it is by listening and hearing we can have the best vision. Marine mammals are the ocean canaries, warning us about the disastrous effects of pollution and habitat destruction, and they can be our guides to find answers, to questions we have not yet thought to ask about the ocean realm.

It is through the long- term studies like the one we have been carrying out in Palm Beach waters, that dolphins teach us about the ocean, the world and ourselves. We just have to keep going to school.

 

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We all depend on a healthy ocean; a healthy ocean depends on us. Let us be the change we would like to see in the world. Our new Ocean Sentinels Club is proof that conservation can be fun, rewarding and effective. The Club unites and empowers citizens to advocate for the conservation of dolphins and the marine environment across Palm Beach County, and beyond. Join us. The time is now. It begins with you.

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Dolphins as Sentinels for Oceans and Human Health

Over the past 50 years, a great number of previously un-known human diseases emerged, while other well-known maladies, including cholera and tuberculosis, have seen a significant resurgence. Not surprisingly, dolphins and other marine mammals experience a similar trend, with various papillomaviruses, dolphin poxvirus, lobomycosis, various neoplastic diseases, and algal bloom bio-intoxication being among the better-understood disease agents or diseases. Our experience in human medicine should cause all of us to be concerned about the deterioration of aquatic eco-systems, coastal freshwater or marine, especially since they support more than half of the population in the U.S. alone.

Monitoring the overall health status of dolphins provides an excellent avenue to evaluate the wellbeing of entire aquatic systems, and identify possible environmental trends. Dolphins are the ocean canaries, warning us about existing and emerging threats not only to the aquatic eco-systems, but also to human health. But dolphins are also charismatic and instill the desire to be part of a solution in many people who otherwise may not care. No doubt, it is in our own best interest to closely observe any patterns that could affect us.

Let’s focus here on the most talked about water-related issue in the past two months in south Florida has been the catastrophic, harmful algae bloom that descended onto the Port St. Lucie River lagoon and associated waterways all the ay to the coastline. Algae blooms have become a regular occurrence in this area for years, but this year’s outbreak was larger by order of several magnitudes.

While some people may think that such algae blooms represent little, if any dangers, it is well established that such blooms produce neurotoxins that can kill dolphins and other marine life, as well as biotoxins that affect human health. Among those threats to our own wellbeing are brevetoxins and saxitoxins that cause poisoning, and okadaic acid, which causes diarrhea.

Some recent disease outbreaks (epizootics) among bottlenose dolphin populations in southeast Florida serve as prime examples of how studying dolphins can help us manage health risks. Several of these outbreaks were associated with brevetoxins, produced by a dinoflagellate called Karenia brevis. That is the same species causing the so-called red tides. Brevetoxins are known to kill and/or contaminate fish and shellfish. Once we consume those, or simply inhale toxic aerosols, we will fall ill. It is noteworthy to emphasize that the actual exposure may be delayed, meaning that the risk to human health continues long after, or far away, from the original dinoflagellate bloom.

In sum, any increase in toxins, whether due to natural or anthropogenic cause, in our coastal habitats must be of great concern to us. While we may not yet fully understand how these toxins are absorbed and travel through the entire food chain, there is no doubt that dolphins can serve as the sentinels for ocean and human health.

We all depend on a healthy ocean; a healthy ocean depends on us. Let us be the change we would like to see in the world.  Our new Ocean Sentinels Club is proof that conservation can be fun, rewarding and effective.  The Club unites and empowers citizens to advocate for the conservation of dolphins and the marine environment across Palm Beach County, and beyond. Join us. The time is now. It begins with you.

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Why It Is Important To Study Wild Dolphins

Most people love whales and dolphins. They think of them as intelligent creatures. They have heard stories of dolphins coming to the aid of stranded sailors, guiding swimmers back to shore and engaging in cooperative hunting with local fishermen. They feel whales and dolphins are important. And they are right! Maybe more than you might think!

Whales and dolphins embody most of what we need to understand about oceans. They are predators at the top of the food chain and can tell us a lot about what is important in the ocean; where are sites of high productivity, what is the most energy efficient way to travel, and what are the best senses to use in the water.

Because of their complex behavior and social structure, whales and dolphins are especially interesting. But they also offer us a window into the physiological and anatomical adaptations to aquatic life; information we can apply to echolocation and boat sonar. More than valuable intellectual exercises, these studies help us understand phenomena such as population decline, recovery, and extinction, and teach us to care about the world. Generally, understanding begets caring.

Further, whales and dolphins are a vibrant part of the global ecosystem and their populations have been severely affected by, and continue to be extremely vulnerable to human impact, including interactions with fisheries and whaling. Above all, marine pollution and habitat degradation looms as the most menacing threats of all. If we have any philosophical leanings towards preserving nature, either for future generations or for its own value, than learning enough to prevent this damage is crucial.

Lastly, whales and dolphins, are the archetypal ‘charismatic mega-vertebrates’. Throughout centuries, whales and dolphins have played major roles in myths and legends. Every culture that has come into contact with an ocean, have created myths and legends about how whales and/or dolphins came into being, and what their existence means to the world and to us.

In our times, whales and dolphins have come so symbolize, more than any other species, the concern for the environment and have become a special symbol of sharing the earth. People react to them with empathy and express concern for their welfare. They epitomize and illustrate many of the problems humans inflict on the sea. They engender, in people who might not otherwise care, a wish to improve the ‘health’ of the marine environment. The huge interest in these animals can therefore be used to encourage interest in the sea more generally, with whales and dolphins becoming flagships or ambassadors of the oceans.

All that makes it important to study these wonderful creatures. If you understand dolphin echolocation and how it works, then you have the tools to apply that knowledge. If you are a conservationist and are concerned about dolphin entanglement in nets, knowledge allows you to reduce that risk. The application of the knowledge depends on what you value: for an academic, to further knowledge and understanding; for an applied researcher, to be able to provide information to managers on the implications of a range of management options, for a conservation biologist: to find ways of ensuring the health of populations and habitats.

For more than thirty years, bottlenose dolphins (Tursiops truncatus) have been studied along the west coast of the United States, the Gulf of Mexico and along the eastern sea border, from the Carolinas to the southern tip of Florida. I have been involved with Coastal Dolphin Conservation through the Palm Beach Dolphin project of the Taras Oceanographic Foundation, headquartered in Jupiter, Florida. This project provides critical information on coastal dolphin communities, their lives and societies and shed light on how the health of these top predators, and the conditions of the natural resources they depend on, may directly or indirectly impact our own health and well-being.

In light of the enormous impact whales and dolphins have on humans and their lives, it is not difficult to understand why studying them serves the support of all of us. Search the Internet for the word dolphin sometime and see how many ‘hits’ you get. People believe that whales and dolphins have value and people put their money in things they hold interesting.

Why do dolphins hear sounds up to 150kHz while we hear only to 15? What is there to listen to anyway? Why do only male humpback whales sing and why don’t females? What directs Humpback whales in Hawaii to swim directly north in the summer? How do they know which way is North? Do dolphins ‘see’ an image in their brain from echolocation signals that is similar to what we see with our eyes? Does a dolphin think, and if he does, what does he think about? Do whales dream? Why are blue whales the biggest animals that have ever lived on earth? Why do dolphins have pointy rostrums? But most importantly why does anyone care about the answers to these questions? The main point is that people do care, and this is why we should all take a stand, and invest our time and money into understanding and protecting these marvelous marine mammals. No doubt, life is better with dolphins around.

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