Do plankton provide oxygen and food for other aquatic organisms?

Yes, plankton play a crucial role in aquatic ecosystems by providing both oxygen and food for other organisms. Phytoplankton, a type of plankton, perform photosynthesis and produce a significant portion of the world's oxygen. Additionally, zooplankton feed on phytoplankton, serving as a vital food source for various marine animals, including fish and whales, thus supporting the entire aquatic food web.