What happens when a population reaches its carrying capacity?

Diversity Increases.

New Individuals will immigrate.

Organisms form random distribution patterns.

The ecosystem cannot support more growth.

The ecosystem cannot support more growth.

Explanation:

The ecosystem is at its maximum capacity, like how many people you can fit in a room. If there's too many people then everyone would suffocate. Just like if there is too many organisms, the food, or water, would run out and they would starve, or die of thirst.