Ecological Impact of Humans(EXTRA CREDIT)

NOTE: IN ORDER TO RECEIVE CREDIT YOU MUST ANSWER IN COMPLETE SENTENCES ON A SEPARATE PIECE PAPER!!!!!!

Introduction (p.150)

1. What is biodiversity?

2. Why is biodiversity one of earth’s greatest resources?

3. Define Extinction.

4. What is an endangered species?

5. How does human activity reduce biodiversity (4 ways)?

6.What is habitat fragmentation and why are small fragments “bad” for species?

Pollution Questions (pg. 152)

  1. Why was DDT thought to be a perfect pesticide?
  2. Describe the two properties of DDT that made it dangerous.
  3. What process is described in figure 6-16? Summarize the process.
  4. Which trophic level(s) will experiences the highest levels of pollutants?
  5. Because of the roughly 90 percent loss of energy at each step in a food chain, any consumer has to eat far more food than it ultimately stores as body tissue. If the food contains some material which is not digested and cannot be excreted (usually fat soluble rather than water soluble) that material will accumulate in the consumer's body. A carnivore eating the first consumer will receive a high dose of the material, which it, in turn will retain and pass on to the next level if eaten. In a sample ecosystem there are 100 small fish, each with one part DDT in their system.
  6. Estimate how many large fish there would be in this ecosystem.
  7. Estimate the total DDT concentration (in parts) in each large fish.
  8. Estimate the number of fish eating birds in this ecosystem.
  9. Estimate the total DDT concentration (in parts) in each fish-eating bird.
  10. DDT has little effect on plankton and fish, but has significant effects on birds. Propose two reasons why DDT affects birds and not plankton and fish.
  11. DDT was banned in the U.S. in 1972, but a CDC study in 2002found that more than 50% of fish-eating birds sampled had measurable amounts of DDT. What are some reasons for these findings?

The following is a quote from U.S. Department of Health and Human Services and U.S. Environmental Protection Agency. “Mercury is a heavy metal that is stored in the fatty tissue of fish and mammals. Mercury occurs naturally in the environment and can also be released into the air through industrial pollution. Mercury falls from the air and can accumulate in streams and oceans and is turned into methylmercury in the water. It is this type of mercury that can be harmful, mostly to unborn babies and young children. Fish absorb the methylmercury as they feed in these waters and so it builds up in them. It builds up more in some types of fish and shellfish than others, depending on what the fish eat, which is why the levels vary.”

  1. The website continues to suggest that pregnant women and young children not eat Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury. What trophic levels are these fish?
  2. The website also suggests that the shrimp, salmon, pollock, and catfish are low in mercury. What trophic levels are these animals?

Introduced Species (pg. 153)

  1. What is an invasive species?
  2. Nutria, a water plant eating rodent, has been introduced in the southeastern United States. What are some likely problems caused by the Nutria?
  3. If the nutria, an herbivore, is introduced to a marsh ecosystem what could happen to the other herbivores in the ecosystem? What could happen to carnivores in the ecosystem?
  4. Fountain Grass (Pennisetum setaceum) is a local example of an invasive species. Fountain grass produces as quickly as and more quickly than many native species. Fountain grass seeds germinate as quickly as and more quickly than many native species. Fountain grass thrives in nutrient poor soil, such as sand and rock. Describe how fountain grass has displaced local vegetation in many of our costal areas.
  5. How can fountain grass influence the costal food webs? What happens to the native produces in the ecosystem? What could happen to the herbivores in the ecosystem?

Conserving Biodiversity (pg. 154)

  1. What is conservation?
  2. What is the current focus of conservation efforts? Why?
  3. The book states that conservation regulations must be based in solid research. Propose three research studies or experiments that you would conduct to better understand the coastal sagebrush or chaparral ecosystem, which is the one we live in.
  4. What are biodiversity hot spots? Why is it so important to protect them?
  5. If you have been to a zoo, wild animal park, game preserve, national forest, or state park draw upon those experiences to describe three examples of our current efforts to protect various ecosystems.