What will happen if the blue whale gets extinct

Whales play an important part within the marine ecosystem, and if they were to disappear, the delicate balance of nature would be disrupted. According to Scitable, every time a whale dies, it leaves behind a carcass that provides food and vital nutrition for literally hundreds of marine life organisms. For instance, species of scavenger crustaceans and worms feast upon whale carcasses for sustenance.  

Other species of fish, including sharks, also obtain food from a whale carcass. Without this bountiful source of food, certain parts of the ocean would cease to thrive.

Living whales also heavily contribute to the marine ecosystem in the form of whale feces. According to the Columbia Basin Fish and Wildlife News, a study found that whale feces is filled with rich nutrients that include nitrogen, which stimulates the growth of plants. Organisms, such as plankton, that feed the ocean food chain also benefit from tons of whale feces floating on the ocean's surface. The disappearance of this source of natural nitrogen is likely to have a negative effect on plant and food production.

An overpopulation of sea lions would quickly be evident as soon as the whales that prey on them vanished. Likewise, the economies of Canada and the United States would suffer from a lack of tourist dollars because whale watching is very popular.