Musicians from the West Australian Symphony Orchestra perform a “Symphony in the Sea” at North Cottesloe Beach on December 2, 2008 in Perth, Australia. (Photo by Paul Kane/Getty Images)

The sea otter (Enhydra lutris) is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Adult sea otters typically weigh between 14 and 45 kg (31 and 99 lb), making them the heaviest members of the weasel family, but among the smallest marine mammals. Unlike most marine mammals, the sea otter's primary form of insulation is an exceptionally thick coat of fur, the densest in the animal kingdom. Although it can walk on land, the sea otter lives mostly in the ocean.

The worlds largest cruise ship, the 361 metres long, Harmony of the Seas, arrives in port for her mayden voyage, in Southampton, Britain May 17, 2016. (Photo by Peter Nicholls/Reuters)

People manoeuvre into position as they take part in a mass nude art installation entitled Sea of Hull by New York based artist Spencer Tunick in Hull, England, Saturday July 9, 2016. (Photo by Danny Lawson/PA Wire via AP Photo)

In this Monday, March 28, 2016 photo, trainer Catrina Bloomquist works with Nav, an 11-year-old rescued California sea lion, as part of a new exhibit opening at the Georgia Aquarium. The aquarium is in the midst of celebrating its tenth anniversary, and as part of the festivities, patrons will be introduced to the newest faces in Atlanta, a group of rescued California sea lions. (Photo by David Goldman/AP Photo)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

An Iranian girl walks at the Tochal ski resort, in north of Tehran, Iran on December 12, 2019. (Photo by Nazanin Tabatabaee/WANA via Reuters)

A woman jumps with balloons while she poses for a picture at a park in Kiev, Ukraine May 6, 2018. (Photo by Valentyn Ogirenko/Reuters)