Nice idea this and there are some good shapes colours and textures on the shells. Not entirely sure it works, partly because of the reason above. Perhaps the light needed to be warmer, maybe it needed a macro lens to get in closer to an individual shell..... Still a good idea with lots to look at.
I love to collect these when at the beach, however I usually have to look hard for them. Looks like I would be leaving with a full bag from this beach. Lovely texture and colors to this shot!
~Kim