Are there any freshwater aquatic mammals?

Question

All of the aquatic mammals I know of like dolphins, whales, and seals are saltwater.

Answer 1

Only semi-aquatic, I think.  Otters, muskrats, nutria, capybara, beavers....

Answer 2

From tiny water shrews to moose & elephants, yes!!

Answer 3

Manatees, Baikal seal, river dolphins, platypus, beavers, hippos, etc. Dugongs are saltwater (we get them in Australia so I know). Intrestingly I’ve seen bottlenose dolphins in saltwater rivers and lakes.

Answer 4

Dugongs and Manatees, but they also venture into salt water. 

Answer 5

beaver and platypus is all I get off the top of my head.

Some dolphins can do fresh water or sea water.

Almost forgot otter.

Answer 6

Yes of course, there are marine mammals that have adapted themselves to fresh water. For example, the Yangtze River dolphin and the Amazon River dolphin live in fresh water. River otters, muskrats, beavers and the duck billed platypus spend a lot  more time in the water than on land. Many seals and sea lions in fact spend more time on land than river otters. Therefore it is often difficult to draw a line between semi-aquatic mammals and aquatic mammals. 

Answer 7

If I recall my course in limnology, mammals such as beavers, muskrats, and nutria, although they spend a lot of time in the water, are semi-aquatic, not aquatic. BTW, the ones you mention would be considered marine (for the most part), rather than aquatic.

Answer 8

There are Amazon River dolphins, and also South Asian river dolphins. The Baikal seal lives in Lake Baikal, Russia. Many other examples are listed, Wikipedia is your friend.

Source(s): https://en.wikipedia.org/wiki/Aquatic_mammal

Answer 9

Sure.  There are river dolphins.

There are also things like otters, beavers, muskrats, hippos, pygmy hippos.

... and then there are things like capybara and nutria.

Answer 10

Florida manatees can move freely between fresh water and salt water.

Source(s): https://en.wikipedia.org/wiki/Manatee#Ecology