Answer:
More number of algae is present on coral reef.
Step-by-step explanation:
The population of algae present on the coral reef highly increases because the sea urchin feeds on the algae present on the coral reef. Sea urchin abundance of species populations is very important for coral reefs as a counterweight. It acts as a balancer of coral reefs due to the sea urchins themselves which generally eat algae found on coral reefs so if sea urchin population decreases, the algae present on coral reef increase in population.