|Leatherback Turtle near Green Island-Cairns North Queensland|
The special thing is that there are no published records that I can find for leatherback turtles (Dermochelys coriacea) near Cairns. The nearest record in the Atlas of Living Australia is from Mackay and dates from 1985. Another record shows on the map near Cooktown, however this record is for a fossil! Leatherback turtles are endangered, so this sighting is significant.
The water was clear and there were some small clumps of floating yellow-brown algae, probably sargassum and occasional lines of widely dispersed mangrove detritus. However there were no major collections of floating materials which would indicate a downwelling zone and there was no other wildlife activity in the area. In the water, transparent jellyfish with fine filaments at the edge of the bell were visible (Aurelia?) on the reef. I even photographed one strange jellyfish then realized that the bell had been eaten by something, probably a turtle. Leatherback turtles eat jellyfish as do green turtles.
Checkout the teeth a Leatherback has for dealing with jellyfish in this blog