Plankton play a crucial role in marine food chains as they are the primary producers at the base of the food chain. Phytoplankton, which are plant-like plankton, use sunlight to photosynthesize and produce food, serving as a source of energy for other marine organisms. Zooplankton, which are animal-like plankton, feed on phytoplankton and in turn, are consumed by larger marine animals such as fish, whales, and jellyfish. Therefore, plankton are essential in transferring energy from the sun to higher trophic levels in the marine ecosystem.