Probably "Xenylla littoralis" "Original description on Flickr:" :"When I was staying in Montagu on the NE coast of Tasmania, these Collembola were very common but interestingly, only just below the high tide mark, as was another species that I'll post up tomorrow. Within a few centimetres above this line, they disappeared and I couldn't find them, even with repeated searching. A lot of springtails seem well adapted to extreme conditions, these ones mainly under rocks, perhaps where air pockets could be trapped when the tide came in. The more I watch these animals, the more I'm impressed by how they can live in conditions unfit for most other things. They grazed on the algae you can see in the main photo, living in communal piles of up to fifty individuals that I saw. The ID comes from P. Greenslade."