As we went for another long beach walk kept noticing marks in the beach.  Finally realised that they were scrape marks from sand dollars.  Picked one up and placed it down again and it started to spin itself around and burrowed itself beneath the sand.

This one just dived into the sand like a flying saucer ploughing into the sand (like in the movies).

The beach here is zoned in animals related to moisture and tidal excursion.

In the upper shore are sand blubber crabs (Scopimera globosa), digging holes and making sand pellets.  They stay in their burrows during high tide and come out when the tide goes out.  The sand pellets radiate out from their holes and are washed away with the incoming tide.  The small crabs seem to be low down the shore, the bigger ones high up.  The dark colour of the upper shore is caused by lots of balls of sand. 

In this shot you can see tiny scratch marks.  The crabs come out of their holes, scrape up the sand feed it towards their mouths.  Not sure if the detritus is scraped off and eaten or whether all the sand is eaten.  Whatever, the sand balls are the ejected material.

You can just make out the crab here, almost dead centre.  Its hole is in the bottom RH corner.

In the wetter area towards the sea you get the sand dollars.  In the drier parts their tracks are all rucked up, in the wetter parts the tracks are smooth. 

These two were on a collision course.  They touched and then went their separate ways.

Those tracks I mentioned yesterday seem to be lower down the beach.  Now where did I leave my hat?