| Dolphin, Chinese River | |||
| Genus | Lipotes | ||
| Species | vexillifer | ||
| Status | Endangered | ||
| Habitat | Rivers, ocean | ||
| Distribution | China | ||
| Behavior | Dolphins navigate through the ocean by using echolocation. This is done by producing a series of clicks that travel as soundwaves through the water. The waves hit an object and reflect back, and the returning "echo" tells the dolphin the location, size, and shape of the object. They can also use echolocation to avoid enemies such as sharks. | ||
| Conservation |
Dolphins are mainly endangered because of a fishing method devised in the 1950s. Fishing crews would spot dolphins feeding above a school of tuna fish, circle the entire school, and drop their nets. But when they did this, they captured not only the tuna, but the dolphins also. The dolphins were either drowned or crushed in the fishing machinery before they could be released.
By 1972, nearly four million dolphins had been killed by this method, and many injured animals escaped only to die later. In the 1970s laws were passed to stop this practice, but they were not enforced, so dolphins continued to die in large numbers. Finally, in 1987, a tuna boat killed between 200 and 300 Costa Rican spinner dolphins, which made up half the population of this rare species. These killings were filmed and shown on television. It was discovered that during the 1980s, 113,000 dolphins were killed in nets each year. People were so outraged that they stopped buying tuna, forcing tuna companies to use other methods of fishing that wouldn't hurt dolphins. Unfortunately, some crews still use the old methods. Dolphins also face ocean pollution and decreasing numbers of fish, two more factors that reduce their populations. | ||
| Interesting Facts |
All dolphins have teeth and belong to the family of toothed whales. The smallest dolphin species is the Heaviside's dolphin, and the largest is the orca, or killer whale.
Dolphins and porpoises are often confused, and though they are related, they look very different. A porpoise is smaller than a dolphin and has a rounder snout. It doesn't have a beak and its teeth are spade-shaped. A dolphin has more pointed teeth in both jaws, a rounded forehead (called a melon), and possesses a beak-like snout. | ||
| Animal Communication Panel | |||
 Back
|
|