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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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The Objectives of Marine Mammal Research

The aim of marine mammal research is to develop progressive knowledge and understanding of their biology, adaptations, behavior and ecology, which will lead to better protection of species and their habitats, contributing to biodiversity in such a way that a sustainable use of the sea becomes possible.  Furthermore, such research strives to understand how we affect their lives and how we can gain from them, e.g. through tourism.

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, the knowledge allows you to build better fishing nets that will not harm them.  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.

In the end, all this will contribute to a better understanding of the impact we have on our planet.  You can’t have seven billion people growing and running around on a planet without having some major impacts.  Right now we are making choices we don’t even understand; better to make an informed choice don’t you think?

There are various tools that can be used to achieve this goal, including expanding the knowledge base through biological inventories, research, monitoring, training of professionals, planning (environmental impact assessment), action plans and integrated area management, regulating threats to marine species and ecosystems, establishing protected areas, and ensuring active involvement of citizens in government decision making.  Public education is very important in all conservation efforts.

 

Most of science consists of answering very small questions.  Each one may not have much value in and of itself, but when the whole picture is to be seen, each of the many small pixels of knowledge will be required.  So in the long term, we can expect to truly understand some of the things that are affecting cetaceans and their behavior.  In the short term, however, one cannot expect too much.  Important results in this field are usually gained through long-term research, which will then constitute the wisdom and the power to make the best possible decisions about the future.  Research aimed only at solving a specific, well-understood short-term problem is not going to provide us with the answers we need ten or twenty years from now.  We need to commit some fraction of our resources, our dollars, to basic science, understanding that it is a risk-taking investment; not all science hunches pay off, but when they pay off, they pay off big.  And this investment of resources should not be done because it is `en vogue’ to be concerned about the animals, the oceans and the planet, but because it is intellectually and morally the correct thing to do.  By better understanding one group of marine creatures, with which we compete for resources – prey and habitat -, we may be able to better manage our affairs on this planet.

In sum, excellent research provides several results: Firstly, it leads to a deeper understanding of the world and its basic mechanisms of function, or in other words, an increased appreciation of the world in which we live.  Secondly, it provides a baseline of data against which we can measure changes and information that can be put to practical use, thus reducing our impact on these animals and their environment.  And third, the advancement of knowledge usually entrains an increase in public awareness and then support from the general public, which is a crucial determinant for maintaining biodiversity, the survival of the variety of species and their habitats and a wise resource use by man.

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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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Threats to Whales and Dolphins

Whales and dolphins are a vibrant part of the global ecosystem and their populations have been severely affected in various ways.

Many species have been over-hunted in the past, and several populations are reduced to a small fraction of their original levels. They are vulnerable to entanglement in fishing gear and incidental catch in gillnets is one of the most serious threats to marine mammals.  These fishery operations may well cause the extinction of several small cetacean populations within the next few decades, including the Vaquita and Chilean dolphins. Collisions between larger whales and ships (ship strikes) occur with regular frequency and represent a significant cause of death and traumatic injury.  Because toothed whales and dolphins are top predators and thus at a higher tropic level in the food chain, they are especially prone to bio-accumulating toxins, such as heavy metals, persistent organic pollutants (POPs) and endocrine disrupting chemicals (EDCs). However, as recent research has demonstrated, such toxins and pollutants also negatively impact baleen whales.

Another threat to the health of whales and dolphins comes from the petroleum industry. Seismic surveys, which are used to discover oil and gas field situated below the seabed are, at a minimum, suspected to damage the complex hearing system of these marine mammals. Once the oil extraction processes is under way, the negative impacts shift habitat loss and exposure to hydrocarbons, lubricants and outright pollutants and toxins used in the process.

Loss of whale and dolphin habitat is directly linked to increasing human activity in and along marine environments. The aggregation of wastes we allow to flow into our streams and estuaries, and ultimately into the oceans, is a biochemical soup carrying thousands of different chemicals. Rainwater and snow melt, that run off from congested urban areas, collect street oil and chemicals as well as many metals. Runoff into streams and rivers adjacent to farmlands carry tons of suspended particles of soil. This is not only damaging to fish but can also choke-out submerged oxygen-giving grasses in coastal woodlands, bays or estuaries. Runoff from timber harvesting activities, especially clear cutting, deprives the exposed land of thousands of tons of soil and has caused the pollution of some of the most valuable spawning grounds for trout and salmon in the Pacific Northwest. Runoff of the nitrogen and phosphorus components of fertilizers leads to an oxygen depletion in the water. This depletion has caused massive fish die-offs and can wipe out whole areas of marine habitat necessary to maintain the life cycles of myriads of species of aquatic life.

Marine debris is a visible expression of human impact on the marine environment. Debris is more than an aesthetic problem, it poses a real danger. Ocean currents carry milk cartons, toothbrushes, cigarette lighters, and other familiar plastic items around the world. In some areas, such as the Central Pacific Gyre, plastics outnumber plankton seven to one.

The number of marine mammals that die each year due to ingestion and entanglement of debris approaches 100,000 in the North Pacific Ocean alone. Worldwide, 82 of 144 bird species examined contained small debris in their stomachs. Plastic is the most far-reaching man-made threat facing many marine species. Over time, it reacts with sunlight and turns into small plastic polymer molecules. It turns out that these plastic polymers are sponges for DDT, PCBs and other toxins that don’t dissolve in seawater. Plastic pellets have been found to accumulate up to one million times the level of these poisons that are floating in the water itself. These pellets are consumed by baitfish, which in turn are consumed by larger fish, eventually finding their way into the stomachs of large predators, such as dolphins and toothed whales, and our own.

Other human activities, such as the construction of shipping channels and marinas, and the recreational use of coastal areas, including resort development, are likely to have a negative impact on the lives of whales and dolphins using the same areas.

Last but not least, climate change, with its changes of sea temperature, sea level rise, changes in salinity, just to name a few, will undoubtedly change the socio-ecology of whales and dolphins. Species inhabiting the high latitudes, such as bowhead, narwhal, beluga may be the first to feel the impact due to diminishing food resources, such as krill. But other species, such as humpback whales and killer whales will likely experience significant changes in their food supply, resulting in changes of existing migration patterns and a shift of home ranges.

Whales and dolphins are facing enormous challenges and threats. They are the ocean canaries, warning us about the disastrous effects of pollution and habitat destruction, and they can be our guides to where to look for answers about how our oceans work. If we have any philosophical leanings towards preserving these wonderful creatures and the oceans, either for future generations or for its own value, than learning enough to prevent any further damage is crucial.

 

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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