Gooseneck Barnacles

[update] – The source of the pumice is likely to be from the 2012 Havre Seamount eruption 800km NE of New Zealand. The eruption of this undersea volcano produced floating rafts of pumice estimated to be up 26,000 km²! Thanks for the info Matt!

These shelled creatures are known as Gooseneck barnacles. They were covering the recently washed up pumice on Elizabeth beach. Many of them were still alive, you could see them extending their fan like fronds.