Conservation and field management of the freshwater crayfish, Euastacus spinifer (Decapoda: Parastacidae), in the Sydney Region, Australia

Much of the natural range of Euastacus spinifer, in the Sydney region, is now included in the metropolitan and associated urban areas. Whilst a green belt of National Parks provides some reserves, these refuges are known to have been modified to varying degrees and many waterways outside Park boundaries are severely degraded. Based on current biological knowledge of E. spinifer and experience with other Euastacus fisheries, a number of management options for this important macro-invertebrate are presented together with specific recommendations. Although effective conservation will require a number of interacting waterway and catchment programs, it is suggested that: recreational harvesting be restricted to the largest individuals (>85 mm CL) with small bag limits (5/person/day); a short annual closure (March-June) be declared; permanently closed areas be established with upgraded monitoring and response systems. The ease of individual marking, sedentary behaviour, limited physiological tolerances, polytrophic status and longevity are all characteristics enhancing the potential of E. spinifer as a biological indicator. The types of catchment features, local habitat characteristics and biotic site data considered important for inclusion in quantitative habitat assessment for this crayfish, are briefly discussed.