QUESTIONS (C): 6. What areas of the ocean are the most productive? 7. How does the nature of the substrate affect the kinds of organism found at the shore? 8. What is the role of each of the following organisms in a marine ecosystem: phytoplankton, zooplankton, algae, coral animals, and fish? 9. List three differences between freshwater and marine ecosystems. 10. What is an estuary? Why are estuaries important?

1. Group 12:
1. PHAI MINEA [Leader: 0966153104] (ID: 2119055)
2. LAO SOKKEANG [0966973633] (ID: 2119639)
3. OL KIMMEY [098661176] (ID: 2120522)
4. RITH CHHAINGIM [0969071860] (ID: 2121245)
5. OSOTH RATANADAVID [086455494] (ID: 2119875)

2. REVIEW QEUSTIONS
QUESTIONS (C):
6. What areas of the ocean are the most productive?
7. How does the nature of the substrate affect the kinds of organism found at the shore?
8. What is the role of each of the following organisms in a marine ecosystem:
phytoplankton, zooplankton, algae, coral animals, and fish?
9. List three differences between freshwater and marine ecosystems.
10. What is an estuary? Why are estuaries important?

3. ANSWERS
PART(C):
6. What areas of the ocean are the most productive?
Answer 1:
Although they occupy less than two percent of the oceans, the coastal upwelling areas
in the eastern parts of the Pacific and Atlantic Ocean are among the biologically most
productive marine areas worldwide.
7. How does the nature of the substrate affect the kinds of organism found at the
shore?
Answer 2:
The kind of the substrate determines the kinds of organisms that live near the shore.
For example, rocks provide area for the attachment, that sand do not, since sand is constantly
moving. Mud usually has little oxygen for the construction of new living organisms. In water,
these are often in short supply.
8. What is the role of each of the following organisms in a marine ecosystem:
phytoplankton, zooplankton, algae, coral animals, and fish?
Answer 3:
the role of each of the following organisms in a marine ecosystem: phytoplankton,
zooplankton, algae, coral animals, and fish:
 Phytoplankton: is the planktonic organism that carries on photosynthesis.
 Zooplankton: It feeds on the large population of phytoplankton.
 Algae: provide both themselves and the coral animals with the nutrient for growth.
 Coral animals: eat zooplanktons and algae as primary food source.
 Fish eat the zooplankton and it is eaten by large fish such as shark, salmon, or tuna.
9. List three differences between freshwater and marine ecosystems.
Answer 4:
List three differences between freshwater and marine ecosystems:
Freshwater Marine
• It is not the largest ecosystem
• The less salt
• such as lakes and rivers.
• It is the largest ecosystem
• The more salt
• such as estuaries and the ocean.

4. 10. What is an estuary? Why are estuaries important?
Answer 10:
An estuary is a special category of aquatic ecosystem that consists of shallow,
partially enclosed areas where freshwater enters the ocean.
Estuaries are particularly productive ecosystems and nursery sites for fish and
crustacean.