Do dolphins, whales or other sea mammals drink seawater ?
If so, do their kidneys concentrate urine more effectively than mammals that drink freshwater. A: It is very likely that marine mammals incidentally ingest sea water with their food, although there is inadequate information about the exact amount taken in. Baleen whales and some pinnipeds feed on crustacean organisms, which have a high salt content compared to fishes. Since whales do not possess sweat glands, they must eliminate excess salt from the body via urine production. The kidneys of whales and seals are able to produce a urine which is more concentrated than seawater; whale urine is reported to have a chloride concentration of 820 mmol/L, while seawater is approximately 535 mmol Cl/L. Whale kidneys have numerous divisions which increase surface area, allowing a greater removal of salts from the blood than human kidneys. If a human were to drink 1 L of sea water, there would be a net water loss of approximately 350 mL. This is why, if you’re stranded at sea and severely dehydrat
