Phytoplankton, also known as microalgae, are microscopic, single-celled photosynthetic organisms that live suspended in water and form the base of the aquatic food web

. They are similar to terrestrial plants as they contain chlorophyll and require sunlight for photosynthesis

. Phytoplankton can be found in both marine and fresh water environments

. Some key characteristics of phytoplankton include:

• They are primary producers in the ocean, transforming inorganic carbon into organic compounds

• They provide food for a wide range of sea creatures, including shrimp, snails, and jellyfish

• They can form harmless algal blooms (HABs) when there are too many nutrients available, which can produce toxic compounds harming fish, shellfish, mammals, birds, and humans

There are two main classes of phytoplankton: dinoflagellates and diatoms

. Dinoflagellates have whip-like tails and complex shells, while diatoms have rigid shells made of interlocking silica

. Phytoplankton are crucial for maintaining the balance of marine ecosystems, as they generate about half of the atmosphere's oxygen and form the base of virtually every ocean food web