Question

tide pools are habitats for several kinds of organisms that attach to the rocky surface and depend upon tides for food and oxygen. sea stars present in these tide pools feed on mussels and other shellfish that have no other natural predators. how will it most likely impact species diversity if all of the sea stars are removed from the tide pool ecosystem?
diversity will increase as the rate of predation decreases.
diversity will decrease as competition for space increases.
diversity will increase as the recycling of nutrients decreases.
diversity will decrease as food and oxygen supplies increase.

Explanation:

Sea stars are predators. When they are removed, their prey (mussels and shellfish) will have less predation pressure. But since these prey attach to rocky surfaces (limited space), without sea - star predation, their population will grow. As their numbers increase, competition for the limited space (a crucial resource in tide - pool ecosystems) among these prey species will intensify. This increased competition will lead to a decrease in species diversity as some species are outcompeted and may disappear from the ecosystem.

Answer:

Diversity will decrease as competition for space increases.