Been a while since I've been to this chat page, this one has more than one chat page with the same picture, it happens sometimes, as equipment malfunctions, it is here to stay now , in any case, yes i saw the Crabs when I first looked at it, soooo none since, three years and no sightings of them tells me they have gone away or have been eradicated, likely as a nuisance, shame, it was nice to watch them scamper around when someone moved.  They seemed bigger than Fiddlers, so, some sort of local species I would guess