According to Whale Facts, whales are important because they are an essential part of the ocean ecosystem. For instance, they keep the flow of food regulated and the food chain intact. In turn, certain species of marine wildlife don't overpopulate.
Blue whales consume an incredible amount of krill per day. If they weren't present to balance the krill population, the food web would become unbalanced. Phytoplankton use the nutrients in whale feces to grow and thrive. In turn, other marine life feed off of phytoplankton. Also, phytoplankton clean the air, removing up to 400,000 tons of carbon from the atmosphere per year.
Scientists learn about echolocation, or sonar, by observing whales. Researchers aim to understand how whales use echolocation as a way to learn more about other marine species and devise better ways to protect ocean animals from man-made noise. Several species of whales have been used by the military for rescuing people and locating underwater mines.
Whales are also important to the economy. At one point, whale parts such as oil and blubber were sold for use in manufacturing. Now, whales are important to the economy from a tourism standpoint. People pay money to whale watch, which boosts local economies.