What fish can bike through a coral? how do these fish contribute to beach formation?

There's actually an entire documentary made about this certain fish, its name is Parrot Fish.

The reason for its name is because it has a beak, which it uses to bite and eat through coral.

And at the end of the day, when the fishes poop, it turns into sand.

For example, one 2010 study in Marine Biology found that large parrotfish in Hawaii can churn out 840 pounds of eroded coral—i.e. white sand—per year. A single giant humphead parrotfish can produce 11,000 pounds of sand per year.

hope this helps!

Asmall closed hole formed in an outwash plain or moraine. forms when a  glacier retreats then remains stationary.