Activity Worksheet 1 – Using Figure 1
1. Name 8 organisms that are abundant in this ecosystem.
2. Name 3 rare organisms in this ecosystem.
3. List 2 producers in this ecosystem.
4. List 8 consumers in this ecosystem.
5. Within this food web, find and write out a 5-step or greater food chain.
6. What do the microbes eat?
7. Are microbes producers, consumers, or decomposers?
8. If whales and turtles become rare in this ecosystem, what would you expect
to happen to the number of jellyfish?
9. If whales, sharks, seals and alligators were removed from the ecosystem,
what would you expect to happen to the numbers of predatory fish?
10. If the oyster population was reduced (became less), what would you expect
to happen to the number of microbes, phytoplankton/algae and detritus?
Activity Worksheet 2 – Using Figure 2
1. Name 6 abundant organisms.
2. Name 8 organisms that are rare or extinct.
3. Redraw the food web including only the abundant species.
4. How is this food web similar to the original food web?
5. How is this food web different from the original food web?
6. Why do you think jellyfish are now abundant?
7. Why are there fewer (less) predatory fish if there are fewer whales, sharks,
seals and alligators?
8. Why have the phytoplankton (floating plants or algae) increased in number?
9. What happened to the seafloor plants? (Hint: Like all plants, what do the
seafloor plants need to grow? What does nutrient runoff cause to grow that
would limit that resource that the seafloor plants need to grow?)
10. How does this food web show the problem of high nutrient levels in the
water? (Hint: Oysters filter the nutrients, microbes, and phytoplankton from
the water. Use the food web to explain what happened to their numbers and
why.)
11. Make a hypothesis for how harvesting (collecting/catching) oysters affects
nutrient pollution.
Activity Worksheet 3
You will use the provided graph to graph 1)the oyster catch in relation to
years before present and 2) Nutrient levels in relation to years before
present.
1. What is the independent variable?
2. What are the dependent variables? (2)
3. Why do you think the nutrient pollution in the bay began to increase about
250 years ago? (Hint: It has to do with the arrival of European settlers.)
4. Nutrient levels stayed steady, or similar, for almost 200 years at 3 and then
suddenly increased 60 years ago to 8. Use your graph to decide what
happened to the oyster catch 60 years ago.
5. How might the shortage of oysters lead to an increase in nutrient levels in the
bay 60 years ago? Use what you know about the role of oysters in the bay’s
food web to answer this question.
6. Why are so few oysters being caught today compared with 100 years ago?
7. How could we help solve the nutrient problem and help the oyster industry
Activity Worksheet 4
1. How have humans affected the Chesapeake Bay food web?
2. Explain the role oysters play in keeping the nutrient levels in the bay low.
3. Use your food webs and data from Worksheet 3 to list at lease 5
consequences of the altered (changed) food web of the Chesapeake Bay.
4. How can understanding what a food web used to look like help us
understand today’s ecosystems?