Question

Why do whales and dolphins often come upto water surface

Answer 1

to inhale oxygen
hope it helps.

Answer 2

Since whales and dolphins do not respire with the help of lungs or gills , they breathe in and out with the help of their nostrils . So they often come up to the water surface in order to breathe .
I hope this answer would help you .
Please my answer as brainliest.