There is clearly a concern in the Tasmanian lobster industry about the status of inshore component of the stock. Catch has declined in a number of areas, despite improvements in catch rates. In the Northeast, catch is at record lows, but CPUE has remained stable, which is a possible indicator of hyper-stability or false stability. The apparent stability in catch rates occurs because aggregations containing a major proportion of the population are fished down, as the fleet moves from one area of good catch rates to the next, resulting in a serial depletion of the aggregations, which is masked by the apparent stability in the fishing block. This can result in a very sudden decline in biomass once the entire block is depleted, posing a serious and immediate risk to the inshore component of the stock. There are two potential sources of this problem. Firstly, the scale of the current assessment model, of eight inshore areas (64m) and three offshore areas (>64m) is not be fine enough to detect localised changes in the CPUE or biomass. Secondly there are changes in fishing practices that have increased effort on inshore stocks, and it is unclear whether the extra effort in these practices is adequately recorded in estimates of CPUE. There has been a recent increase in potting effort, commonly referred to as double night fishing, whereby fishers set and haul their pots twice a night, compared to the standard practice of emptying pots once at dusk and/or once during the day. Currently we have no data on the composition of the catch in double night shots, and what proportion of captured lobsters are handled and released, and in fact what consequence this handling has on the overall health of the fishery.

Knowledge of changing environmental conditions and productivity as a result of climate change is essential for adaptive management. In addition to direct applicability to fisheries and aquaculture in southern Tasmania, this information will have numerous important applications to other industries and stakeholders in the broader catchment.

CSIRO and TAFI have established a program (INFORMD- Inshore network for observation and regional management: Derwent-Huon) to guide multiple use coastal zone development and management. Storm Bay is an integral component of the INFORMD region and a priority is to understand both the short term (climate variability) and long-term (climate change) drivers of productivity in the region and link these to production of fisheries and aquaculture. CSIRO have a project investigating novel observing technologies (NOTe) to characterize the Derwent to shelf environment and TAFI will fund a charter vessel to monthly sample water column environmental variables, and support the CSIRO observing system. Thus an opportunity exists to obtain nutrient and productivity data in the Storm Bay region in a very cost-effective manner by collaborating with the existing research program.

Important background information is that the East Australian Current is predicted to penetrate further south causing significant warming and decreased productivity. Previous work (Harris et al 1991) showed that the nutrient status of waters clearly indicated the influence of the EAC, and primary producers indicated the productivity of the region, demonstrating the potential for Storm Bay to act as an indicator of productivity for Southern and Eastern Tasmania. Such information is important to understanding changes in fisheries and aquaculture production and, as a consequence, to assist with developing climate change adaptive management strategies.

This project also provides an opportunity for FRDC to invest in a project that will have significant influence on multiple use management in Australia.