What role do zooplankton play in freshwater ecosystems?

Zooplankton play a critical role in freshwater ecosystems, primarily by serving as a food source for various aquatic organisms, including fish and larger predators. This position in the food web is essential for transferring energy from primary producers, like phytoplankton and other microscopic plants, to higher trophic levels. By consuming phytoplankton, zooplankton facilitate the conversion of this primary production into energy that can support larger animals, thus maintaining the balance and health of the ecosystem.

Moreover, the presence of zooplankton can influence the dynamics of the food web, as their population dynamics can affect the growth and survival of fish populations. They also help in nutrient cycling within the ecosystem, contributing indirectly to the overall productivity and diversity of freshwater habitats. This makes them vital not just as a food source but as key players in the functioning of ecosystem processes.