http://www.imdb.com/title/tt0371724/quotes :

Dolphins: [singing] So long, and thanks for all the fish / So sad that it should come to this / We tried to warn you all, but, oh, dear / You may not share out intellect / Which might explain your disrespect / For all the natural wonders that grow around you / So long, so long, and thanks for all the fish!
Dolphins: [singing] The world's about to be destroyed / There's no point getting all annoyed / Lie back and let the planet dissolve around you / Despite those nets of tuna fleets / We thought that most of you were sweet / Especially tiny tots and your pregnant women / So long, so long, so long, so long, so long! So long, so long, so long, so long, so long! So long, so long, and thanks for all the fish!
Dolphin: [singing] If I had just one last wish / I would like a tasty fish!
Dolphin: [singing] If we could just change one thing / We would all have learnt to sing!
Dolphins: [singing] Come one and all / Man and mammal / Side by side / In life's great gene pool!
Dolphins: [singing] So long, so long, so long, so long, so long / So long, so long, so long, so long / So long, so long and thanks for all the fish!