How does a shark maintain buoyancy

1. Watch Mark Rober ... He's great!

2. A shark maintains his buoyancy because a shark was the same amount of force pushing awards as gravity is pulling is downwards. So instead of sinking it floats. I know that didn't make a lot of sense but seriously, watch Mark Rober and you will know everything! (unlike me, a freshman)

3. P. S. If you want to learn more about buoyancy, I suggest you watch the balls in the liquid sand video