What I learned today as a Whale Museum Docent - August

Every time I go into the Whale Museum to tend the display floor and answer questions - I end up learning new things about whales.

Today:

Question: Did you know that whale's have growth rings on their teeth? In a very similar fashion to growth rings on a tree, a whale's age can be roughly determined by how many growth rings there on a tooth.

Question: How do whales get fresh water?
Huh?
Well, they are mammals, afterall. This question was asked by the new education curator with a sparkle in her eye.
We talked about it and then I looked it up. Sure enough, whales get fresh water from what they eat. It isn't just that what they are eating have H2O in them, but one of the byproducts of eating the other critters is - you guessed it - water.
One of the articles I read said that many sea mammals - like whales - have very large livers that help them process the salt in the water they digest. Most sea mammal's urine has a very high concentrate of saline.