Zooplankton refers to a diverse array of small, drifting animals that inhabit bodies of water, primarily oceans, seas, and freshwater systems. The term "zooplankton" is derived from the Greek words "zoo," meaning animal, and "planktos," meaning wanderer or drifter. These organisms are defined by their lack of swimming ability against currents, making them largely at the mercy of water movements.
Zooplankton constitutes a crucial component of aquatic ecosystems, serving as primary consumers and critical links in the food chain. They include a variety of organisms, such as tiny crustaceans like copepods, krill, and shrimp, as well as various larval forms of fish, mollusks, and other invertebrates. Some species of jellyfish, comb jellies, and certain types of worms are also considered zooplankton.
These microorganisms play a vital role in marine and freshwater food webs, serving as a food source for numerous larger organisms. They consume phytoplankton, microscopic algae suspended in water, and in turn, serve as prey for many larger predators, including fish, marine mammals, and seabirds. Additionally, zooplankton contribute to the carbon and nutrient cycling in aquatic ecosystems, as they release waste products that can be recycled by other organisms or sink to the ocean floor.
Due to their abundance, diversity, and sensitivity to environmental conditions, zooplankton are often utilized as indicators of water quality and ecological changes within aquatic ecosystems. Studying zooplankton populations can provide valuable insights into the health and dynamics of marine and freshwater environments, aiding in the assessment and conservation of these vital ecosystems.
