Why can't humpback whales survive in fresh water?

Question

My dad said that it was because God made it that way; true; I guess, but there has to be some scientific reason to it.

Answer 1

All animals have a 'niche' where they can survive, and with the possible exception of humans, niches are relatively narrow. A penguin can't survive in a desert since there are no fish and they would overheat. A zebra can't survive in a forest since they eat grass and trees keep grass from growing.

To begin with, humpback whales might not be buoyant enough in freshwater to keep from sinking. Also, freshwater environments probably do not produce enough of the food that a humpback eats. Humpback whales are big creatures that need a lot of food. They feed by opening their mouths and filtering tiny shrimp and other small plankton out of the water. There has to be very high densities of food for the whale to survive with this type of eating, and the only places in the world where the food is plentiful enough is in the ocean along a narrow band parallel to to coast. Water from deep parts of the coastal areas get pushed up to the surface, which brings all sorts of algae and nutrients for the shrimp and plankton. Humpback whales cannot survive in areas that do not have ocean upwelling, and there are no freshwater systems that have this type of environment.

Answer 2

A humpback whale can survive just fine in freshwater. It will not take in water and explode. The main reason the whale dies in freshwater systems is that there is no food for it there, the freshwater is much more shallow and the whale becomes sunburned and there are typically boats, people and land surrounding it which stresses the whale. Also, the pH of the freshwater is different which can irritate the whales skin, leading to parasites taking hold and stressing the whale. The whale is also probably is poor shape when it enters freshwater, which could be why it dies in the first place.

Answer 3

Well the answer to this question is valid for almost all marine animals.... Every marine animal has its body salt concentration and its body structured to prevent loss of water to high salt concentration containing saline water. So when you put the animal in freshwater (with much lower salt concentration then in saline sea water) it starts gaining water in a way which causes its organs to fail ,due to cell death.The phenomenon responsible for this is called osmosis.

Answer 4

http://en.wikipedia.org/wiki/Osmosis

"Osmosis is an important topic in biology because it provides the primary means by which water is transported into and out of cells."
That would be the key.

They pump full of water...they'd explode slowly, like cherries in too much rain.
On the other hand, if you put a fresh water creature into salt water, it dries out. You can see that on your hand - if you take a long bath, your hand is all crimpled because of the water drained out of your skin. :)

Answer 5

yes there is. Why don't pigs fly? Because they don't have wings.