The removal of plankton from an ecosystem would have a significant impact on the food chain. Plankton are a major food source for many species of fish, crustaceans, and other aquatic organisms. Without plankton, these species would have to find alternative food sources, which could lead to a decrease in their populations. Additionally, the removal of plankton could lead to a decrease in the populations of species that feed on these organisms, such as whales, dolphins, and seabirds.