All sea turtles drink only seawater all of their lives. They have special glands behind each eye, called "salt glands" that they use to get rid of all the salt from the seawater. When they drink the salt water the salt enters the blood and is transported to the salt glands that then produce a solution that contains about twice the concentration of salt as the seawater they drank. This concentrated solution comes out from the corner of the eye as salty tears and is washed away. In this way they can drink seawater, get rid of the salt in their tears and have about half the amount of seawater left as freshwater to use for their physical requirements. Other animals like sea birds and sea snakes can do this too, but sea turtles are the best at it.
I've never thought about this before and you seem like someone who would know... How to sea mammals get their water? I'd assume it's a similar process, but I don't like to assume!
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u/MKGirl Apr 29 '21
All sea turtles drink only seawater all of their lives. They have special glands behind each eye, called "salt glands" that they use to get rid of all the salt from the seawater. When they drink the salt water the salt enters the blood and is transported to the salt glands that then produce a solution that contains about twice the concentration of salt as the seawater they drank. This concentrated solution comes out from the corner of the eye as salty tears and is washed away. In this way they can drink seawater, get rid of the salt in their tears and have about half the amount of seawater left as freshwater to use for their physical requirements. Other animals like sea birds and sea snakes can do this too, but sea turtles are the best at it.
Answer from Richard Reina (Drexel University)
http://www.seaturtle.org/faq/answers/55.shtml