In an antarctic ecosystem, phytoplankton are eaten by krill, which are eaten by baleen whales. if the population of phytoplankton suddenly decreased: the population of whales would increase. the population of whales would decrease. the population of krill would increase. none of the above.

The population of whales would decrease.

Explanation:

Organisms feed on one another in their name environment in order to obtain energy needed for their life processes. The habitat described here is aquatic, and it involves a series of organisms involved I feeding pattern called FOOD CHAIN. Every food chain starts with an autotroph i.e. an organism that is capable of making Its own food by trapping light energy from the sun.

This autotophs are called PRODUCERS. The producer in this case are PHYTOPLANKTONS, which starts the food chain. If the population of the producer (phytoplanktons) decrease, there will be a reduction in the number of consumers at each trophic level i.e. the number of krills and whales will also decrease because only a producer is capable of starting a food chain.