What would happen if the Atlantic Puffin became extinct?

Answer 1

IT is neither extinct nor endangered. Current population estimates are six million.

If it became extinct, there would be no more.

Answer 2

Then we would have to be content with the Prelated Horned Puffin (Fratercula corniculata) from the North Pacific.

Although the Atlantic puffin population is declining in some areas, it is rising or stable in many others.

See
http://en.wikipedia.org/wiki/Atlantic_Puffin