of fire roads and double track trails can consequentially allow illegal fishers to access previously unexploited populations. Habitat disturbance Habitat disturbance for A. gouldi includes the removal or destruction of native riparian vegetation, bank erosion, removal of snags, stream flow alterations such as culverts and farm dams, siltation and toxic chemical runoffs. The clearance of riparian vegetation causes the destabilisation of waterway banks, which impacts the burrowing habitats for A. gouldi and increases sediment runoff into waterways. Increased sediment levels arising from agricultural and forestry related land-uses have been correlated with decreased abundances of freshwater crayfish. The increase in turbidity impacts the ability of the crayfish to effectively transpire oxygen through its gills. Sediment depositions arising from upstream forestry operations have been observed to impact in-stream habitat for considerable distances downstream of up to 10 km. Loss of riparian canopy cover allows more light to reach the water and has a negative impact on habitat by increasing water temperatures. While Tasmanian river basins have been found to be generally less impacted by flow alterations than other catchments across Australia, some river basins (such as the Mersey and Pipers–Ringarooma river basins) are heavily impacted by hydro-electric schemes, with the use of in-stream barriers reducing the dispersal potential of the crayfish. Water extraction for irrigated agriculture and urban water use is of concern to a lesser degree, however there has been an identified lack of contingency plans in the event of reduced environmental flows in waterways. Anecdotal reports indicate that low environmental flows caused the death of giant freshwater crayfish in several catchments in the north-west and north-east of Tasmania in 2006–07 Notable events In 1994, a large spill from a holding dam at a pyrethrum extraction plant caused a major kill in the Hogarth Rivulet and the main channel of the Great Forester River. Reports from locals and fisheries officers suggested that there was little life left in much of the main channel, and the incident is believed to have severely harmed any populations that were in the waterways at the time of the spill. The 2016 Tasmanian floods, which killed 3 people, raised concerns about the future for the Tasmanian giant freshwater crayfish after up to 100 carcasses were found washed up along the banks of the Leven River on a property in North West Tasmania, likely caused by the high water flows during the flood. Previous population surveys in