Cockles

There are three tasks focusing on cockles: one looking at observations; one reading food chains; and one looking at relationships in a marine ecosystem.

Cockles live in sheltered coastal areas around New Zealand.

cockles

They are a very important food source in some marine ecosystems.
 

Question Change answer

Question 1
Question 1 is about some of the observations and inferences made by scientists about how cockles are suited to their tidal environment.
Observations are what you notice. What you think about your observation is an inference. Below are observations and inferences that scientists have made about cockles.
 
Sort the statements into the correct boxes. 
Cockles could dry out when exposed to the air
Cockles feed on plankton because they cannot move to hunt for their food
Cockles are sessile (move very little)
When you open a cockle shell water falls out
Strong waves have damaged cockle shells
Cockles have a sturdy heavy shell
Observations
Inferences

Question

Question 2
Question 2 is about cockles in food chains. In a food chain the arrow shows the direction in which the energy flows. In one food chain cockles eat phytoplankton and are eaten by crabs.
 
Which food chain below shows this?

    • phyto-to-cockle-to-crab.png

    • Both-arrows-towards-cocckle.png

    • Both-arrows-away-from-cockle.png

    • Crab-cockle-pytoplankton-(arrows-leading-to-pyhtoplankton.png

cockles

Cockles are an important link in the food web of organisms that live in the coastal waters of New Zealand. Imagine what would happen to the organisms of this food web if people took large numbers of cockles for themselves. 

Questions 3 & 4 assesses your understanding of the interdependence of organisms in a food web.

Question

Question 3a)
 
food web for decreasing cockle numbers
 
Use the food web to decide all the organisms that will be immediately affected by a decrease in cockle numbers.

    • Cod

    • Bivalve molluscs

    • Crabs

    • Rock lobsters

    • Shrimp

    • Zooplankton

    • Phytoplankton

    • Seabirds

3b) Choose one organism that you ticked would be immediately affected. Explain how it will be affected.

Question

Question 4a)
food web for decreasing cockle numbers
 
Choose all the organisms from the food web that will be affected in the long term by a decrease in the cockle numbers. 

    • Cod

    • Bivalve molluscs

    • Crabs

    • Rock lobsters

    • Shrimp

    • Zooplankton

    • Phytoplankton

    • Seabirds

4b) Choose one organism that you ticked would be affected in the long term. Explain how it will be affected.