The impact of urchins (i.e. Centrostephanus) on reef habitats in south-east Australia has been increasing for over a decade, and may be related to climate change (FRDC 2009/070). Urchins can clear and maintain areas of reef free from macro-algae, and reduce the productivity of abalone populations and other reef species. Extensive research projects to monitor urchin populations and reduce their impacts have been completed or are under-way in NSW, Victoria and Tasmania. There is an urgent need to consolidate the findings of these research projects, and to quickly plan and coordinate the on-going development of responses to the spread of urchins.
There is evidence that production from commercial fisheries in NSW, Vic and Tas has been reduced by the spread of urchins. Small-scale clearance of urchins, and the translocation of abalone, has demonstrated the ability to recover abalone populations impacted by urchins, but consequent return of production has not yet been demonstrated in any fishery. In eastern Victoria, a joint project between Industry and Government has recently seen commercial-scale removal of urchins from previously-productive abalone reef, and the consequent recovery of appropriate habitat for abalone over a large-scale. There is now a tactical opportunity and strong need to take advantage of these removals before urchins re-invade, to demonstrate that past research can be scaled up to larger areas of reef and recovery of larger abalone populations, with the intent to maintain them over long-periods to demonstrate outcomes of sustained productivity.
Recent observations indicate urchins have also spread to western Victoria, where abalone are still recovering from Abalone Viral Ganglioneuritis. There is also an urgent need to both develop a survey to estimate the extent of Centrostephanus in western Victoria, and to investigate the potential of translocating abalone at a large-scale to re-establish populations in depleted areas, before urchins spread further.