Whales Essay Research Paper IntroductionWhale is a

Whales Essay, Research Paper

Introduction

Whale is a large mammal that lives its entire life in water. Like other mammals, whales have a large highly developed brain and nurse their young with milk. Whales resemble fish in many ways, but they are not. Fishes are cold blooded and breathe underwater using gills. Whale maintains a warm, constant body temperature of about 37 degrees Celsius (about 99 degrees Fahrenheit) and breathes underwater using lungs. Unlike fish, whales move their tails up and down when they swim instead of moving side to side done by the fish.

Whales can be found in all oceans and seas in parts of the world, rivers and lakes in Southeast Asia, South American tropics, Northern America and various other parts of the world. Whales are enormous in size compared to other mammals but at the same time, it is also one of the biggest animals living today. There are over seventy- five different species of whales and each species has its own unique characteristics. Now today, I would like to start the presentation off by talking about the different groups of whales and the different species within the groups. Since there are so many different types of whales, I would like to talk about the whales that I believed to be very important.

Whales are divided into two groups; toothed whales and baleen whales. The toothed whales have jaws lined with simple pointed teeth. These whales actively hunt fish and squid. Toothed whales vary in size from one s that are six feet long to the great sperm whales that average fifty-five feet in length and can weigh nearly fifty metric tons. Among the more unusual toothed species are the narwhal and the beluga, which both inhabit the Arctic waters. From the toothed whales, I will be talking about the beluga whale. The second group known as baleen whales, instead of having teeth, they have mouths lined with giant flexible combs of a material called baleen, or whalebone which is used to filter small fish from the water. There are three types of baleen whales: the rorquals, the gray whales and the right whales. From this group I would like to talk about the southern right whale, northern right whale, bowhead whale, gray whale, blue whale and humpback whale. The reason why I chose these whales is because they are listed either as an endangered or vulnerable species.

Beluga Whale

The beluga whale is a small, toothed whale that is white as an adult. Belugas have a small blunt head with small beak, tiny eyes, and a thick layer of blubber. Beluga means white one in Russian. The beluga is also called the white whale. Beluga whales grow to be about 15 feet long on average and weighing about 3300 pounds. Beluga whales are social animals that tend to hunt and migrate in pods- groups consisting of about ten whales. Belugas live in frigid Arctic and sub- Arctic waters, but some populations migrate south to warmer water in the summer. Belugas at the same time also travel up northern rivers into brackish (partly salty) water to hunt prey. Killer whales and polar bears prey on belugas, especially the calves. People have hunted for belugas for hundreds of years but now only a few Arctic tribes hunt for them. It is estimated that there are about 40,000 to 80,0000 beluga whales worldwide. Although there are many still left, the St. Lawrence, Cook Inlet, and Alaskan belugas are classified as endangered. The St. Lawrence belugas are critically endangered with only about 700 remaining. The St. Lawrence belugas are a victim of shipping disturbance including collisions, noise pollution, habitat degradation, and above all toxic contaminants. The beluga is so contaminated by DDT and PCB s that dead carcasses have to be disposed of as toxic waster.

Humpback Whale

The humpback whale is one of the rorquals, a family that includes the blue whale, fin whale, sei whale and the minke whale. The shape and color pattern on the humpback s dorsal fin and fluke tail are different for each whale so it is similar to fingerprints of human. Because of this, new form of research known as photo- identification was made. Each whale is identified, catalogued and monitored so this gives researchers valuable information about humpback whale population, migration, sexual maturity and behavior patterns. Adult humpback measure 40 to 48 feet in length and weigh about 30 tons. Humpback whales are found in all the world s oceans. Most populations of humpback follow a migration routine, summering in temperate and polar waters for feeding and wintering in tropical waters for mating. Because their mating, feeding and calving grounds are close to shore, they were the target for early hunters. But in 1966, the IWC- International Whaling Committee gave them worldwide protection. At present, there are about 15,000 humpback whales living, which is around 15% of the original population.

Blue Whale

The blue whale is also one of the rorquals. On land an animal the size of a blue whale would be crushed by its own weight without the support of large heavy bones. But because its body is supported by water, there were no needs for such large supporting bones. Also with the availability of large food supply have made it possible for blue whale to reach an enormous size. This is why the blue whale is the largest animal ever to live. Blue whales are scattered all over the world but the northern and southern populations do not mix.