Waters along Australia’s most densely populated east coast are warming at 3.8 times the global average rate, which is the most rapid change in the Southern Hemisphere. Ecosystems in this region are likely to be severely impacted by climate change and significant biodiversity change is expected. The rapid nature of these ecosystem changes will require science-based decisions about where, how and when to apply adaptive management interventions. Predictive models have high uncertainty when extrapolated into new conditions, as do CC scenario models. Unless protocols for tracking and predicting ecological changes are well informed, the remote nature of marine habitats, with associated difficulties and expense when mapping biodiversity assets, will inevitably translate to sub-optimal management interventions. Potential management interventions could include targeted spatial closures to protect vulnerable habitats, targeted translocation of key predators, direct manipulation of abundances of threatening and or threatened species.Our project will address these challenges using Australia’s east coast as it is the region of greatest change and hence under the most imminent threat. Using the longest available worldwide (18-yr) ecological reef data record of fishes, invertebrates and macro-algae in marine reserves, we will identify thresholds in ecological responses such as significant assemblage shifts, kelp decline and predator-prey relationships. These outputs combined with future climate scenarios will empower, state management and NRM agencies with mproved capacity to build ecosystem resilience through spatial management actions. The project addresses three NCCARP priority questions by: (3.1) identifying priority ecosystems and species most vulnerable in this globally significant warming hotspot; (2.1) identifying vulnerable inshore reef species of commercial fisheries importance (including southern rock lobster, abalone, and temperate wrasses) and priority locations for adaptive management; and (3.2) clarifying management benefits from one intervention strategy – MPAs – for enhancing resilience of temperate ecosystems.

There is clearly potential for C. rodgersii barrens to cover ~50% of nearshore reefs on the east coast of Tasmania, as is already the case in NSW and the Kent Group in Bass Strait. This would reduce both the Tasmanian abalone and rock lobster fisheries by ~15%, with a loss of value totalling ~$25M (before processing). The need for a management response is self evident.

Large rock lobsters (=135 mm CL) are the key predators of C. rodgersii in Tasmania, and experiments have shown clearly they can prevent sea urchin populations from building to the point where overgrazing occurs. There is urgent need to assess the viability of controlling C. rodgersii populations through changing current management of the rock lobster fishery, and through targeted removal by divers as a tactical response on small scales.

However, before management instruments are invoked in an attempt to minimise the risk of further development of barrens habitat or rehabilitate existing barrens, it is imperative to carefully evaluate the effectiveness of potential management strategies. The proposed research will provide the necessary information and knowledge base to enable robust management decisions.

The proposed work has strong support from managers and the fishing industry in Tasmania, is acknowledged as a high priority by the relevant RAGs, and addresses several high priorities on both the State and TAFI strategic research plans.

Development of urchin fisheries in Australia is currently limited by economic viability due to low recovery rates. This fishery has a large opportunity to expand given:
1. There is a large sea urchin resource
2. The high price urchin roe fetches
3. Low cost of fishing (relatively shallow water).

The opportunity to develop this fishery into a highly profitable one is dependent on the development of innovative solutions. This proposal examines the potential for enhancing recovery rates using supplementary feeding for short periods. If this can be done cost effectively it opens the opportunity to dramatically increase the profitability and size of this fishery. Without this technology the urchin fishery will not fully develop. With this technology the fishery has the potential to be worth tens of millions. This project has been initiated by support through both existing permit holders and Aquaculturists.

With the decline in several other sea urchin fisheries around the world, there now exists a good opportunity to develop a large and valuable fishery for purple and red sea urchins in NSW. In addition, there is also interest in the further development of the purple urchin fishery near Mallacoota in eastern Victoria, and the white urchin fishery in Port Phillip Bay. This interest is evidenced in both NSW and Victoria by substantial capital investment in factories to process sea urchins and their roe. If these urchin fisheries could be further developed within an appropriate management framework, it could also lead to significant benefits for the abalone fishery, particularly in NSW, because of the interaction between the two species.

Because of the limited development of this fishery to date, it provides an ideal opportunity to assess stocks of sea urchins prior to any major depletion by fishing. Sampling techniques have already been developed for sea urchins in barren habitats, and could easily be transferred to habitats where commercial fishing will be concentrated. Such assessments may be particularly important considering the evidence from other urchin fisheries, where large virgin stocks have been rapidly depleted with only low rates of recovery from the recruitment of juveniles.

Preliminary information from NSW suggests a large proportion of the sea urchin population does not contain high quality roe. Unless high quality roe can be reliably collected, the costs of processing sea urchins may restrict development of the fishery. Two main techniques have been used in other fisheries to improve the supply of food to sea urchins on reefs, and hence the quality of roe that can be harvested. If these techniques could be adapted for sea urchins in NSW, significant improvements in yield and value would be possible. Further, as the simple, large scale removals are already being used in the industry, there is also a need to detect their impacts on other species.