Ecology Activity: Energy Transfer in a Model Ecosystem
Integrated Science 1-2 Name: Per: Date:
Introduction
One of the most important factors in any ecosystem is the flow of energy through the ecosystem. Plant tissues form energy–containing compounds, using the energy absorbed from the Sun. Animals that eat the plants obtain this energy. Food is the means by which energy is transferred from one organism to the next organism in the food chain. This lab will allow you to study how energy moves through a model food web in the San Francisco Bay/Estuary.
Procedure
1. Listed below are 9 organisms that are members of the San Francisco Bay Estuary.
2. You are to fill out the chart below showing which what plants and animals act as predators and prey, as well as producers, primary or secondary consumers.
3. Using Word or PowerPoint, you will then create a food web showing every possible (at LEAST 10) energy transfer through the ecosystem.
4. MAKE SURE YOU DRAW ARROWS POINTING IN THE RIGHT DIRECTION FOR THE ENERGY TRANSFER.
5. Once you are completed, you are to raise your hand and have the teacher check your food web. Make sure you are completed with the food web before raising your hand!
6. You are then to answer the questions based on the food web.
Food Web / Chart exhibiting relationships among organisms
Directions: Answer the following questions. If it asks to EXPLAIN, make sure you give a thorough and accurate response and do not just list answers. If you are only using one line to answer the question when there are multiple lines, you are probably not answering the question fully.
Questions based on the Food Web constructed (10 points)
1. Animals that eat plankton throughout their entire lives are called ______
2. EXPLAIN how pickleweed has adapted to living in salty conditions.
______
3. Give me 4 examples of invertebrates.
a)______b) ______
c)______d)______
4. List two endangered species in this Food Web tidal marsh habitat.
a)______b) ______
5. From the images taken from the food web, list at least two organisms for each of the following trophic levels:
Producers-
Primary consumers-
Secondary consumers-
Decomposer (list only 1)-
6. In regards to the food web illustrated, describe what the key factors in creating an ecosystem are (deals with the differing organisms ie: herbivores,
______
7. EXPLAIN why each trophic level in a food chain contains less energy than the level below it.
______
8. What would happen if the cordgrass was removed from the food web? EXPLAIN.
______
9. Why is it more energy efficient for people to eat plants instead of animals? EXPLAIN
Critical Thinking
10. Each year, large tracts of wetlands are filled in or paved over for commercial, residential, and recreational use. What effect could such development have on surrounding ecosystems? (recall it is wetlands being destroyed)
11. An estuary is semi-enclosed coastal body of water with a one or more rivers or streams flowing into it, and with a free connection to the open sea. The key feature of an estuary is that it is a mixing place for sea water and fresh water to supply fresh water.
What goes on with the primary producers in an estuary? Use the words detritus, nutrients and decomposition.
12. What are two major threats that are reducing the productivity and health of the bay. WHY are these two problems major threats. EXPLAIN.