An Assessment of the Distribution, Biology, Threatening Processes and Conservation Status of the Freshwater Crayfish, Genus Euastacus (Decapoda, Parastacidae), in Continental Australia. III. Case Studies and Recommendations

Abstract

In our preceding paper 80% of Euastacus species were assessed as belonging in IUCN threat categories, the majority of these Endangered or Critically Endangered. As an essential part of our review and conservation assessment of this genus, we provide a species case study from each of the IUCN categories, and discuss research imperatives and conservation and management considerations for the genus in general. In addition to continuing basic taxonomic and biological research, on-going population monitoring should be implemented, and research urgently needs to be initiated into the susceptibility of most species to increasing temperature, increasing dryness and/or reduced flow, land use practices, and exotic species (particularly the toxic cane toad, Bufo marinus). For those species with fragmented distributions extending across a number of separate drainages, population genetics studies are required to clarify if the isolated populations are in fact distinct taxa. Conservation prospects of this genus would be enhanced by recognising threatened species under relevant State Conservation legislation, rectifying the chronic shortage of funding for basic, inexpensive and critical research, and adopting the well documented management recommendations. Given their wide distributional parameters, and their presence in essentially the entire spectrum of Australian climatic zones and habitats, Euastacus species will likely be the first to be broadly impacted by the combined effects of the various threats identified: a "sentinel" genus. We suggest Euastacus could serve as early warning indicators for other fauna in Australia, and perhaps other regions of the World.