Q39 - Limpets and Urchins Have Unequal Effects on Seaweed Cover
Sea urchins (Echinoidea) are a major food source of otters (Enhydra lutris). Sea urchin populations tend to explode where sea beds have been damaged by human activities. Sea urchins, limpets (Patella vulgata) and seaweeds can live together. Seaweed coverage was measured in an experimental area where the populations of urchins and limpets was artificially controlled.
Using the information and data, determine which of the statements are true or which are false.
A. Limpets affect seaweed growth when sea urchins are present.
B. Sea urchins have a bigger effect on seaweed than limpets have on seaweed.
C. Sea urchins help damaged seabeds recover.
D. Increasing the number of otters increases ocean primary productivity.
Question reproduced from IBO 2017, Theoretical Exam A, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Official answer key & worked solutions