Yes, SURFFISH is a Scrabble word!

Letter values in Scrabble US: S 1, U 1, R 1, F 4, F 4, I 1, S 1, H 4.

Is it a valid word?

SURFFISH is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a fish of the Pacific coast of North America
small to medium-sized shallow-water fishes of the Pacific coast of North America

Also: yellowfin croaker, surf fish, umbrina roncador.