Blue question mark

Why can't we drink seawater?
— Jessy H., Grade 1

Mammalogist Robert Voss answers this question:

Hi Jessy,

If you drank seawater, the salt would get absorbed into your blood along with the water . That would make your blood too salty. So, your kidneys would have to remove the salt. But to do that they would need to use even more water! That's why drinking seawater would just make you thirstier. It can even make you sick if you drink it too often.

humpback whale

Some marine mammals, like whales, can drink seawater.

Although people can't drink seawater, some marine mammals (like whales and seals) and seabirds (like gulls and albatrosses) can drink seawater. Marine mammals have super efficient kidneys, and seabirds have a special gland in their nose that removes salt from the blood.

Explore More: 

Robert Voss

Robert Voss

Job Title:
Associate Curator, Division of Mammalogy

Known For:
Rob is a mammalogist. He studies mammals that live in the forests of the Amazonia and Andes in South America.

Cool Fact:
Rob is interested in how marsupials are related. Most people think that marsupials live in Australia, but there are lots of them in Central and South America. One species, the Viginia opossum, lives in the United States.

Image Credits:

whales, courtesy of NOAA; Robert Voss, © AMNH.