my layman's understanding is that crustaceans stay pretty much to the sea floor and on land? I mean the fish that hunt them (i.e. trigger fish) tend to do things that get them up off the sandy bottom where they can easily be hunted.
Being tiny, a crustacean, and at the surface in open water is not a good thing. Perhaps someone else knows what these things are?
Uhmmm...Krill?
And, yes, I'm a skeptic, too.