Document ID: chunk:federal_register_of_legislation:F2017L01040:body:0:p13
Version: federal_register_of_legislation:F2017L01040
Segment Type: other
Provision Reference: 
Character Range: 36567–40193

Sub-catchment       Private Freehold, Permanent Timber Production Zone                                               Regional Reserve
  Ringarooma Catchment         Private Freehold, Permanent Timber Production Zone, Future Potential Production Forest (Crown)   Regional Reserve
  Welcome Catchment            Private Freehold, Permanent Timber Production Zone                                               N/A
  Montagu Catchment            Permanent Timber Production Zone, Private Freehold                                               Regional Reserve
May occur***                     Musselroe Catchment                                                                            Permanent Timber Production Zone, Future Potential Production Forest (Crown)                     Regional Reserve
Trans-located pops****           St. Patricks Catchment                                                                         Private Freehold, Permanent Timber Production Zone, Future Potential Production Forest (Crown)   N/A
  Clyde Catchment              Private Freehold                                                                                 N/A

* Known to occur = all locations where the species has been sighted since 1990, including biologically important areas where the species is known to breed, feed or forage. This category is primarily associated with high quality habitat, characterized by low to no sedimentation, no flow modifications and intact riparian vegetation which can allow for recruitment of in-stream woody debris. Note: 'known to occur' and 'likely to occur' categories have been amalgamated in Figure 1 to protect the location of known sites from potential illegal fishing.

** Likely to occur = areas where the species or species' habitat is likely to occur, such as locations adjacent to known distribution polygons or locations where the species has been previously sighted (i.e. pre-1990). Habitat may exhibit a reduction in quality of riparian vegetation and an increase in sedimentation impacts, and densities are expected to be lower.

*** May occur = areas where the species or species' habitat may occur, including locations of anecdotal sightings. Habitat may be significantly compromised.

**** Translocated populations = individuals have been introduced into these catchments and have subsequently established populations; these catchments are not a part of the species historic 'natural' range.

Figure 1: Modelled distribution of the giant freshwater crayfish (Astacopsis gouldi).

4 Threats

4.1 Historical causes of decline
The principal threats affecting giant freshwater crayfish in past decades were fishing pressure and habitat disturbance (Lynch 1967; Hamr 1990b; Horwitz 1994; Growns 1995; Lynch & Blühdorn 1997), with relatively common reports of localised extinctions and large declines in numbers attributed to these threatening processes (Hamr 1990a; Horwitz 1991, 1994; Maxwell et al. 1997). Many of the streams inhabited by the species have been subject to disturbance from agricultural, forestry and urban activities and much of the floodplain riparian area within its range has been heavily modified (Jackson & Blühdorn 1999). With expansion of road construction, primarily a result of forestry activities, many of the species' upland refuges have become more easily accessed for fishing (TSS 2006).
The recolonisation of impacted streams appears to be very slow (e.g. Maxwell et al. 1997), indicating that dispersal is naturally slow or that the animals available for such migrations may no longer be plentiful. The species' slow growth and relatively