THE IMPORTANCE OF WHITE SHARKS http://www.sciencedaily.com/releases/2012/09/120929140238.htm

      


 

                                                                                                    
http://library.thinkquest.org/08aug/01316/Great%20White%20Shark.html
                Picture: This is a picture of a white shark. These sharks help to keep balance in the oceans ecosystem by their individuality and variation of their diets.

               Summary: White sharks, the largest predatory sharks in the ocean, are     thought of as apex predators that feed primarily on seals and sea lions. But a new study by researchers at the University of California, Santa Cruz, shows surprising variability in the dietary preferences of individual sharks. University of Wyoming student Sora Kim said, "We did find that white shark diets changed with age, as expected, but we were surprised that the patterns and extent of change differed among individuals." Paul Koch, professor of Earth and planetary science at UCSC said that not all sharks eat the same mix of prey. He also said, "We confirmed that the diets of many individuals observed at seal and sea lion rookeries shift from fish to marine mammals as the sharks mature. We discovered that different individual sharks may specialize on different types of prey. These two types of flexibility in feeding behavior are difficult to document using traditional methods, but may be very important for understanding how the population is supported by the eastern Pacific ecosystem and how it may respond to changes in that ecosystem." It is important to the ecosystem that these sharks don't go extinct because of human actions. These sharks keep a balance in the oceans ecosystem and they are self relient.   

http://www.globalchange.umich.edu/globalchange2/current/lectures/human_pop/human_pop.htmlPicture:

This is a picture of a graph showing the population of each continent.

Summary:

This article starts out with stating our population growth. Its only taken 40 years since 1950 to get the population to about 5 million. Now the prediction is for the population to reach 8 to 12 billion before the end of the 21st century. The current growth rate is at about 1.3% and thats about 90 million people a year, thats the highest its ever been. The population depends on the fertility rate. The more children the high the population. Some countries have higher birth rates than others. Also the mortality rate(death rate) depends on the population. The demographic transition is the shift from high birth and death rates to low birth as well as death rates. In the end different things help increase and decrease and balance out the population.