Key Words
Predator
Prey
Scavenger
Parasite
Mutualism
Commensalism
The diagram below shows a coastal food web for an environment off the coast of Canada.
Killer whales
Grey whales
Ducks
Surf
birds
Gulls
Humpback whale
Krill
Sea
lion
Bears
Crab
Herring eggs
Hagfish
Ecology FWR L3
Herring
Phytoplankton
 ORB Education. Visit http://www.orbeducation.com for a range of quality teaching materials.
1. Complete the table below using the animals from the coastal food web, the food web (the
first line has been completed for you)
Predator
Prey
Humpback whale
Herring
2. Grey whales (Eschrichtius robustus) are baleen whales that carry small exoparasites on
their bodies near their heads. One of these is the barnacle, which ‘hitches’ a ride and lives
off plankton and food scraps. The other is a small crustacean called ‘whale lice’, that cling to
the whale and eat their skin.
a.
State the type of relationship that the barnacles have with the whale.
_______________________________________________________________
b.
State the type of the relationship that the lice have with the whale.
_______________________________________________________________
c.
The whale, whale lice and barnacles have a unique connection with each other. Which
organism is the host?
_______________________________________________________________
d.
From the coastal food web, name an organism that:
i. Is part of a commensal relationship _________________________________
ii. Is part of a parasitic relationship
e.
_________________________________
Whale lice are described as exoparasites. What does the “exo” prefix mean?
_______________________________________________________________
_______________________________________________________________
Ecology FWR L3
 ORB Education. Visit http://www.orbeducation.com for a range of quality teaching materials.
3. A study was conducted on the stomach contents of killer whales. The type and number of
various mammal species found in the stomach were recorded. The results are shown below.
Prey Species
Harbour seal
Porpoise
Whale
Sea lion
Elephant seal
Bird
Squid
Total
Number of animals
found
8
3
3
3
1
2
1
% of total
number found
a.
Complete the table above, then construct a graph showing the percentage of each
species found in the stomachs of the killer whales.
b.
What conclusion can be made about the dominant prey species of the killer whale?
_______________________________________________________________
c.
Predict the migratory patterns of killer whales and seal populations.
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Ecology FWR L3
 ORB Education. Visit http://www.orbeducation.com for a range of quality teaching materials.