It is well known that someone stranded out at sea in a small boat without water cannot drink the sea water. If they do, it makes them sick. Even if they can keep some of it down, they just get more dehydrated as the body gets rid of more water getting rid of the excess salt.
Sea birds don't seem to have this problem. Albatross species and terns and gulls live far from fresh water and drink sea water constantly without any ill effects. Their kidneys aren't any more efficient at getting rid of salt but they manage to stay healthy.
The trick they have up their sleeve, or rather their nose, is a small set of glands, between the eye socket and the nostril, which is that the top of the beak. These glands actively pump sodium ions and chloride ions out of the blood and into the secretions that come out of the nostril. They use these salt glands to get rid of the excess salt without putting undue pressure on the kidneys.
Sea birds don't seem to have this problem. Albatross species and terns and gulls live far from fresh water and drink sea water constantly without any ill effects. Their kidneys aren't any more efficient at getting rid of salt but they manage to stay healthy.
The trick they have up their sleeve, or rather their nose, is a small set of glands, between the eye socket and the nostril, which is that the top of the beak. These glands actively pump sodium ions and chloride ions out of the blood and into the secretions that come out of the nostril. They use these salt glands to get rid of the excess salt without putting undue pressure on the kidneys.
