Plankton: Ocean Drifters

What are Plankton?

• They are small plants and animals.
• They are any plants or animals that drift with the currents of the ocean.
• They are only microscopic animals.
• They are only microscopic plants.

Which is a kind of phytoplankton?

•  lion’s mane jellyfish
• sea butterfly 
• algae
• copepod 

How does the basket star catch plankton?

• It filters plankton internally.
• It eats small fish that have eaten plankton.
• It uses tiny arms to capture plankton from the water.
• It catches plankton with venomous tentacles.

What limits the growth of phytoplankton?

• The amount of nutrients in the water.
• The number of fish eating the phytoplankton.
• The amount of water that runs off into the ocean.
• The depth of the ocean.

What creates a thermocline?

• A change in the plankton population.
• A difference in the amount of plankton in the ocean.
• A series of strong ocean storms.
• A difference in water temperature.

Why might some whales migrate to the northern Atlantic waters in the spring?

• The whales prefer the cold fresh water of the northern Atlantic.
• Whales can travel to northern waters after the thermocline disappears.
• Plankton are abundant in northern waters in the spring.
• The southern Atlantic waters turn green because there is too much algae.

During the spring bloom, the plankton _____.

• move to the ocean’s surface
• change colors
• slow their growth
• multipliy

In the video, satellite images of the Atlantic ocean showed how plankton populations _____.

• decrease in northern waters in the summer
• increase in the tropics in the summer
• increase in northern waters in the winter
• decrease in southern waters in the fall

Which statement MOST agrees with the video?

• There is so much plankton, it is unlikely that pollution will have any affect on the food web in the ocean.
• Because all ocean life depends on plankton, it is important to make sure that pollution does not harm the production of plankton.
• People need to be careful about pollution only during the plankton bloom.
•  If pollution harmed the production of plankton, only the smallest fish and a few whales would be affected.