Question

whales and dolphins often come up to the water surface. They even release a fountain of water some times while moving upwards. Why do they do so ?

Answer 1

Thank you for asking the question!
Whales and dolphins belongs to same category. They both can come up to the surface of water or ocean and also ejects the stream of water wile moving upwards. This is mainly because they tend to breathe the fresh air  and ejects carbon dioxide. The hole which ejects water is called ''blow hole''. And when they breathe air out of it, it appears like a fountain of water. Blow holes is surrounded by muscles which keep it closed when they are under water.
Hope it helps

Answer 2

Answer:

Whales and dolphins belong to the same category. They both can come up to the surface of the water or ocean and also eject the stream of water while moving upwards. This is mainly because they tend to breathe the fresh air and ejects carbon dioxide. The hole which ejects water is called a ''blow hole''. And when they breathe air out of it, it appears like a fountain of water. Blowholes are surrounded by muscles that keep them closed when they are underwater.