What would happen to the small fish population when there are less big predator fish?

If there are fewer big predator fish, the small fish population would likely increase. Here's why:

* Reduced Predation: Big fish are a primary source of mortality for small fish. With fewer predators, the small fish face less risk of being eaten.

* Increased Survival: As a result of reduced predation, more small fish will survive to adulthood and reproduce.

* Increased Reproduction: A larger population of small fish means more individuals are available to reproduce, further increasing the population size.

* Competition for Resources: The increased small fish population might lead to increased competition for food and other resources.

However, this scenario is complex and depends on other factors:

* Availability of food: If there is plenty of food available, the small fish population can thrive. However, if food becomes limited, competition for resources will increase, possibly leading to a decline in population.

* Other predators: Even with fewer large fish, other predators (like birds or smaller fish) could still prey on the small fish.

* Disease: A crowded small fish population may be more susceptible to disease outbreaks, which could negatively impact their numbers.

* Environmental Changes: Changes in water quality, temperature, or habitat can also influence the small fish population, regardless of predator presence.

In summary, while a decrease in big predator fish would likely lead to an initial increase in the small fish population, the long-term impact would depend on a complex interplay of factors.