If you’re talking about too many people I’m guessing the limitation factors would be lack of resources and that would include lack of food and space.
Viruses is the answer to this
D. Predators
Predators keep populations of other species in check. This was pretty clearly demonstrated in Yellowstone National Park after the wolves were eradicated there. The deer populations increased to the point that the aspen trees nearly disappeared due to the saplings' being eaten by deer. Since the reintroduction of wolves to the park, the aspen trees have begun to flourish once again.
When the capture starts to increase, the fish population
from 50 capture start to 100 capture start upsurges. At 200 capture start, though,
the population augmented in the beginning up until it touched 300 months where
it significantly dropped.
Numerous environmental factors can affect the populace of
fish. First, when there is a hurricane, the fish population will be affected
because the water will move and change.
Second, pollution. When individuals pollute the ocean, it
affects the fishes’ ability to live.
Lastly, when there is a lot of hunters that feed on fish. This
may cause many fishes to be consumed and their population will be reduced.
