An estimated 80% of the world's oceans remains unexplored, with a diverse range of species yet to be discovered, according to the National Oceanic and Atmospheric Administration.
But it's possible we might destroy our oceans before we even discover the extent of life living there. According to a 2016 study by the World Economic Forum, 8 million metric tons of plastic are dumped into the oceans every year, and that number is expected to increase. The oceans are full of distinct creatures from jellyfish and orcas to seals and turtles that have been threatened in recent years by pollution and over-fishing. In fact, humans have already been blamed for ending entire species.
Ahead of Earth Day on April 22, Insider found 20 photos of oceans and their inhabitants that remind us just what we have to lose.

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