Do Whales Drink Seawater

What do whales drink - fresh water, seawater, or nothing at all? Whales are mammals. So are we. And we need to drink lots of water - the standard recommendation is 6 to 8 glasses per day. So whales must need to drink water... or do they? Whales live in the ocean, so they are surrounded by salt water, with no fresh water in sight. As you probably know, us humans cant drink much salt water, because our bodies cant process that much salt. Our relatively simple kidneys would need a lot of fresh water to process the salt, meaning wed lose more fresh water than we were able to extract from the sea water. This is why we get dehydrated if we drink too much salt water. Staying Hydrated Although its not well known how much they drink, whales are capable of drinking sea water because they have specialized kidneys to process the salt, which is excreted in their urine. Even though they can drink salt water, whales are thought to get the bulk of the water they need from their prey - which includes, fish, krill, and copepods. As the whale processes the prey, it extracts water. In addition, whales need less water than we do. Since they live in a watery environment, they lose less water to their surroundings than a human does (i.e., whales dont sweat as we do, and they lose less water when they exhale). Whales also eat prey that has salt content similar to the salt content in their blood, which also causes them to need less fresh water. Sources Garrett, H. Do Whales Drink From the Ocean? ASK Archive. Accessed April 29, 2013.Kenney, R. 2001. How Can Sea Mammals Drink Salt Water? Scientific American. Accessed April 29, 2013.