Dolphins are truly remarkable creatures that live in the oceans of the earth. They are actually part of the group referred to as cetaceans and are directly related to whales. Indeed, they are a type of toothed whale, in the same family as the orca and pilot whale. Dolphins live mostly in the temperate and shallow waters of the continental shelves and are generally grey in color. There are also five species of dolphins that live in some of the world's rivers. These amazing creatures have an extremely high level of intelligence, so much so that they have been studied in great depth. They are also very social animals who love to play and even enjoy human company. Sadly, many species of dolphins are threatened or endangered and about 95% of the deaths of dolphins worldwide are directly related to the actions of humans.
One of the greatest threats to dolphins all over the world is the threat of getting caught in nets. Thousands and thousands of dolphins die each year in shark nets and as bycatch in fishing nets. Since the dolphin is a mammal, they have lungs and, thus, they need to come to the surface for air at regular intervals. Unfortunately, when a dolphin gets caught in a net it usually drowns because it cannot get to the surface in time to breathe. In addition to this, many dolphins die in collisions with ships or by getting caught in the ship's propeller.
Another major threat to dolphins has to do with their sonar. Dolphins detect where they are going in the same way that bats do, by sending out sounds and hearing them rebound off objects. By using sonar, dolphins can tell how far away an object is and how big it is. Humans have created a variety of different and unnatural sounds beneath the water's surface, including ships engines, oil drilling, and especially navigational sonars. These sounds can injure dolphins and can frighten and confuse them so that they lose their way. It has been suggested that this underwater noise pollution is one of the main causes of beached dolphins. In addition, the noise pollution often keeps dolphins away from their feeding and breading grounds.
Of course, we all love dolphins and since they are so very sociable and they will deign to swim with humans, we certainly take advantage of it. So much so in fact, that we are adding to the stresses on the dolphin population by capturing them and keeping them in captivity. The process of capturing a dolphin and transporting it is stressful to say the least. Once they are in captivity, they face possible exposure to diseases they never had to face in the wild and they simply do not live as long. That means more dolphins must be captured to replace them. Even the ones we leave in the wild are at risk due to our attention. The rise in tourists who flock to wild dolphin areas so that they can see them and swim with them have increased the risk to these incredible animals and their habitat.
What about pollution? Of course, there is plenty of that in the oceans thanks to human activity and the dolphins suffer from the effects of it just as all other marine animals do. Oil, chemicals, and heavy metals all end up in our oceans and these have been proven to cause contamination of the dolphin's food, which includes fish, squid, and crustaceans, and there is also high dolphin infant mortality rates and illness as a result.
So what can we do to save these amazing creatures? Fortunately, there are efforts around the world to save the dolphins and help their numbers rebound and stabilize. The ones that are the most endangered are the Chinese river dolphin, the Indus River dolphin, and the orca (killer whale) and these ones are protected under the Endangered Species Act. The Convention on International Trade of Endangered Species offers protection for the Amazon River dolphin, the snubfin dolphin, Indo-Pacific humpbacked dolphin, and the Atlantic humpbacked dolphin. Many dolphins are also protected under the Marine Mammal Protection Act. With these efforts, the protection of the dolphin habitats around the world, and the enforcement of laws regarding the capture and safety of dolphins, we should be able to enjoy the beautiful dolphins in our oceans for generations to come. After all, these intelligent creatures may have something to tell us one day.