Andy and Stefan are in Port Stephens just north of Newcastle completing a survey just outside the mouth of Nelsons bay form Boulder Bay to Broughton Island.

Sea urchins create urchin barren by grazing an area of all plant life. The urchins are then thought to recede due to a combination of lack of food and being eaten by predators such as grouper and snapper. It is hypothesised that if the number of the urchin predators in an area are reduced then the effects of the urchins  are amplified allowing them to become destructive to the marine environment.