Answer: There will be a decrease in the population of sea stars.
Explanation:
Sea starts depend on mussels and other shell fish for their food. if there is an oil spill in the water body and it causes the mussels of an particular area to die then the population that is dependent on mussel as their soul source of energy will decrease in population.
This will happen because of food scarcity. The main source of survival is food and without food the organisms would not be able to survive.
Here, the star fish eat mussels to live, decrease in the number of mussel will decrease the population of sea star.