Is the giant freshwater crayfish threatened, vulnerable or endangered?

Depends who you ask. It is listed as vulnerable under both the Federal Environment Protection and Biodiversity Conservation Act (1999) and the Tasmanian Threatened Species Protection Act (1995). However, it is classified internationally as endangered on the IUCN Red list. Whichever way you look at it, the giant freshwater crayfish is in trouble. Populations are low and fragmented and it survives in a very limited geographical area.