At least, I think it's algae. It doesn't quite look like the rhodophyta in this picture. But some of the images here are similar.
Here is a close up:
I guess I just don't know the beach very well. Yesterday we saw "jumping bluefish" out in Long Island Sound; the fishermen were out in force. Still, until someone explained to me what those little puddles and flecks out in the water signified, I was clueless there too.