Dolphins are marine mammals that are one of the most intelligent creatures on Earth. They are beautiful animals that have caught the attention and love of millions of people all across the globe. However, they often face many hardships and problems that are caused by humans from direct contact or issues that the human race has triggered in general. Perhaps this topic can shed some light on these problems that they undergo while also informing everyone about interesting dolphin facts along the way.
Here is a quick overview of the problems that dolphins face in no particular order:
- sonar testing
- mercury poisoning
- dolphin hunting
- I am sure that nearly all of us have seen or heard about dolphins in captivity, and many of us enjoy or desire to see and interact with them. Even I was fortunate enough to participate in the interactive dolphin program at SeaWorld, San Diego many years ago for my birthday. The experience was like a dream come true for me. I had the honor of getting in the water with a dolphin named Daisy, performing tricks with her, and then finishing the session off with a picture of me having my arms around the creature in a loose hug. What 10 or 11-year old wouldn't want to partake in something so extraordinary? The dolphin that I interacted with was a female, and she had recently had a baby. The newborn actually swam out of its pin and into the large pool that we were in to see her for about a minute, until they put him back in his holding area. A classic, adorable act between mother and child, right?
Although I do not regret my experience with this dolphin, it would have been nice to know all of the problems and difficulties that animals such as these face in captivity. Dolphins are creatures that can swim up to around 100 miles a day in the wild, but in places such as SeaWorld and dolphinariums, they resort to swimming in circles or jumping through hoops during performances. Even with that one fact, it is clear that if I were a dolphin, I would be pretty miserable in captivity. What if you had to learn and perform tricks for your food? It doesn't take a marine biologist or other expert to know that this is a demeaning act for animals such as dolphins. These animals have a lifespan of 45 to 50 years, but over half die within their first two years of captivity due to problems such as stress, diseases, and the pollution(chemicals, bacteria, etcetera) in their tanks. Clearly, captivity is not a healthy environment for dolphins.
Also, tapping on their holding tanks is disorienting and stressful for these creatures. Since they rely on echolocation and can be sensitive to certain sounds, constant thuds and taps on the glass of their tanks can often be unbearable. This may vary depending on the thickness of their tanks, but either way, it isn't necessary to touch the glass. This correlates with direct human contact, as well as feeding a dolphin dead fish. If a dolphin is released, it is highly probable that it will not be able to survive if it has been fed already dead fish for quite an extensive period of time. Thus, they could die of starvation or simply have no choice but to return to their captive state because they cannot survive on their own. Previously captive dolphins have been known to be attacked or ignored by other wild dolphins, or are simply afraid to join a new pod once they have been released.
What if the dolphin was born in captivity?
This is a question that many people probably ask. Sure, a wild dolphin might not be able to survive, but what about one that was born in captivity? Well, this does not change or protect a dolphin from the stressful and unhealthy environment that captivity has to offer.
All of this has made me wonder what became of that juvenile dolphin that I mentioned earlier...
Positive Side of Captivity
Yes, there happens to be a few main facts about captivity that is considered positive: dolphin awareness and the accruing(growing) knowledge of this species. Seeing dolphins in captivity has raised the interest and awareness of millions of people around the world. Without many marine parks or aquariums, most people probably wouldn't care about these creatures as much as many do now. However, my main concern is that people grow to love them for the wrong reasons, such as the tricks that they perform in captivity. Experts have also learned much about dolphins while they have been in captivity. Although the cons seem to exceed the pros in this matter, it is still important for people to know both the positive and negative sides to dolphin captivity, no matter which side they are on.
- Here is a nice piece of information from one of my source sites(www.thecovemovie.com) that sums this section up quite nicely:
Does Navy sonar testing harm dolphins?
Navy testing from next generation sonic devices has been know to cause damage to the brains of cetaceans miles away from test areas. Even at 100 miles away whales and dolphins would hear the sound at 140 decibels, like standing next to an f-15 fighter jet taking off. Whole dolphin and whale pods are frequently found washed up on the shore near navy sonar test sites around the world.
- The disposal of trash, waste, and chemicals via the world's oceans obviously affects the ecosystem of not only dolphins, but all marine life. Dolphins can get sick or become diseased if they come in contact with these waste products. Humans could not live a happy and healthy life if our homes, cities, breathing air, etcetera were infested with filth and trash either.
- The following excerpts will help you understand mercury poisoning:
How does mercury enter the food chain?
Mercury is the most toxic non-radioactive element in the world and it is released when coal is burned. There is no such thing as clean coal. Mercury falls to the ground and is distributed to streams, rivers and lakes and to the oceans where it is consumed by bacteria and becomes methyl-mercury, an organic form that is then easily absorbed by plankton and zooplankton. Mercury is an immortal element; there is no way to get rid of it once it is released in the environment. Once heavy metals and POP’s (persistent organic pollutants like PCB’s or pesticides) are digested they are very difficult to get rid of and they bio-accumulate in all organisms.
As a general rule, every step up on the food chain these toxins are found, they are magnified about 10 times. The result is that at the top of the food chain, apex ocean predators such as dolphins and swordfish have about a million times more pollutants in them than the water surrounding them. When you consume a pound of swordfish you are consuming the equivalent of a million pounds of floating plankton absorbing toxins. Mercury has a half-life in the human body of about 70-90 days but while it is in the human brain it is destroying neurons vital for sensory perception, memory and motor skills. Advanced stages of mercury poisoning in humans look remarkably similar to mental whale, cerebral palsy or dementia in adults.How does mercury affect the dolphins?
Studies have shown that dolphins too are affected by mercury poisoning. Many dolphins washed ashore have been shown to have etched[to produce or possibly ooze, in this case] out grey matter from mercury poisoning.
When people consume dolphin meat, the mercury passes onto them, which lead to the problems that were mentioned above. This was a serious concern in Japan that the documentary film, The Cove, was partly about. Japan had even considered distributing dolphin meat in school lunches for students until the horrible effects of mercury poisoning were made known to them.
- Although the hunting and capturing of dolphins is regulated in many parts of the world, there are still some countries and areas where they are not, including Japan. In Japan, dolphin meat is eaten on a regular basis. The Cove documentary's website, which has a ton of interesting information about dolphins, has a video on its front page that ties in both dolphin hunting and mercury poisoning. It's not graphic or lengthy, and I'm sure that some of you are tired of reading all of what I have typed. x) Here is the link if you want to watch it:
The following elaborates on what I briefly mentioned and what the film sort of covers:
How are dolphins captured?Who eats dolphin meat?
Much of the dolphin meat sold around Japan is actually mislabeled or sold as counterfeit whale meat from larger a whale, which sells for far more money than dolphin meat. Hundreds of samples of dolphin meat tested from around Japan has all been shown to be toxic and far exceeds their own ministry of health recommendations. Some internal organ meat for sale at the Okura markets near Taiji was analyzed to have 5000 times more mercury than the health advisory of 0.4 ppm.
The oceans around industrialized countries such as China, Japan and the United States is some of the most polluted in the world and the dolphins residing in those waters are some of the most toxic in the world. For instance, if fish has more than 2 ppm (parts per million) of PCB’s, the EPA requires that it not be fit for human consumption. Bottlenose dolphins off the East Coast of the United States can have up to 6800 ppm and if one washed up on the shores it would be eligible for clean-up as a super-fund site.
There are probably many different tactics, but "drive hunting" is the one that I will share with you all for now.
In The Cove, they filmed the Japanese fishermen driving the dolphins into a small cove(hence the film's name) by using boats. They would send a small "fleet" of their ships out, and then once they found the dolphins and tried to drive them into the cove, they would place these long metal poles into the water and bang on them. The sound underwater from this clangor would mess with their echolocation, causing the dolphins to feel confused and disoriented, leaving them no choice but to be chased into the cove. Here, they blocked off the cove while they sent much smaller boats of fishermen to literally stab the mass of dolphins to death. Trainers from nearby marine parks were shown there as well. They would capture a few dolphins that they guessed would be trainable, and other than those dolphins, there were no survivors.Source: http://en.wikipedia.org/wiki/Dolphin_drive_hunting wrote:Dolphin drive hunting, also called dolphin drive fishing, is a method of hunting dolphins and occasionally other small cetaceans by driving them together with boats and then usually into a bay or onto a beach. Their escape is prevented by closing off the route to the open sea or ocean with boats and nets. Dolphins are hunted this way in several places around the world. The largest number of dolphins are hunted using this method in Japan, however the practice also occurs in places as far apart as the Solomon Islands in the South Pacific, the Faroe Islands in the North Atlantic, and Peru in South America. Dolphins are mostly hunted for their meat; some are captured and end up in dolphinariums.
INTERESTING FACTS ABOUT DOLPHINS
- Dolphins are very social animals. Here is an interesting paragraph about their socialization:
Dolphins are the most social creatures on the planet, often both male and females stay in the same pod for life. Orcas, the largest of the dolphin family, stay with their mother for life. If the matriarch of the pod is killed or captured, much of the knowledge of the pod is not passed on to the survivors.
- Dolphins use echolocation to communicate with one another and for hunting purposes.
Source: http://www.dolphinkind.com/echolocation.html wrote:Dolphin Echolocation
Echolocation is a sensory sonar system that dolphins use for communication and for locating things in their environment.
Dolphins release a focused beam of clicking sounds (sound waves) and then listen to the echo. From this they can determine the following about an object (such as a fish).
* internal structure (depending on the object)
Echolocation enables the dolphin to see in a much more complex way than it might seem. In fact, the information available from echolocation includes things that we would not notice or see with the naked eye. Depending on the object, sound waves can enter beneath the surface therefore giving feedback and information of the internal structure of an object.
The dolphin's echolocation sensory system is fascinating and complex and remains a mystery in many ways. There are theories that dolphins may view their surroundings holographically and are able to transfer these holographic images to other dolphins. We do know that echolocation is extremely sensitive and allows dolphins to examine small objects hundreds of yards away!
- There are 32 different species of dolphins. The most commonly known species is the bottlenose dolphin, and it is considered one of the easiest to train, which is why it is the commonest species in marine parks or dolphinariums.
Orcas, or Killer Whales, are one of these thirty-two species. Many people are often confused or mislead about this fact.
If you would like in-depth information about each of these species, here is a site I found that lists them all and has information for each of them: http://www.everythingdolphins.com/SpeciesPG.htm
- Dolphins are the only known wild animals that will come to the rescue of a human being. In the OPS film David Rastovich, probably the best-known free surfer in the world, tells how he was rescued from a shark attack by a bottlenose dolphin. On a dive trip to Rangiroa in Polynesia, a pod of resident dolphins playing in the deep blue around director Louie Psihoyos left suddenly to attack and push away an approaching large great hammerhead shark. (Source: www.thecovemovie.com)
- A bottlenose dolphin can dive up to 300 meters(990 feet)
However, the depth that a dolphin can dive to depends on the species. Most dolphins tend to live in shallow waters that are around seven feet deep.
- The average dolphin species can hold its breath for about 8 to 10 minutes.
Because dolphins can store more oxygen in their blood, they can stay underwater longer than the average human.
(Here, I have listed the sources that I used to compile much of this information. Although I credited them above in a few areas, I just want to ensure that they are fully credited in this section. This post wasn't purely copy and paste. It was generally written in my own words, minus the quotes.)
http://www.ehow.com/about_4598087_can-d ... reath.html