Scientists believe the Arctic is home to about 20,000 species, and an international team of researchers is working to pin that number down by documenting all of the Arctic's life forms.

The study will document all species from narwhals and polar bears to plants and single-cell organisms. (Associated Press)

The Arctic Council is conducting the Arctic Biodiversity Assessment project. Lead scientist Hans Meltofte said describing the current state of the Arctic ecosystem is the first step to understanding the changing state of life in the North.

“From single-cell organisms to blue whales, polar bears, anything. Plants, insects, invertebrates in the sea — you name it,” said Meltofte.

Meltofte said scientists believe most of the mammal, fish and bird species in the Arctic have already been identified and described.

But he expects there are still many insects, plants and smaller sea creatures that haven't yet been documented.