CategoryHierarchies.com

Plankton encompasses a diverse group of drifting organisms, predominantly microscopic and residing in both freshwater and marine ecosystems. These minuscule life forms are integral to aquatic food chains and contribute significantly to global biogeochemical cycles. They can be broadly categorized into two primary groups: phytoplankton and zooplankton. Phytoplankton, often referred to as the "grass of the sea," consists of photosynthetic organisms such as algae and cyanobacteria that generate their own energy by converting sunlight, water, and carbon dioxide into oxygen and organic matter through the process of photosynthesis. Zooplankton, on the other hand, are heterotrophic organisms that feed on phytoplankton or other zooplankton and include a wide variety of species such as crustaceans (e.g., copepods, krill), jellyfish, salps, and various larval forms of fish and invertebrates. Plankton populations are influenced by environmental factors such as temperature, light availability, nutrient concentrations, and water motion. They play a crucial role in the ocean's carbon cycle and serve as an essential food source for many larger aquatic organisms, including whales, seals, fish, and birds.