THREATENED SPECIES SCIENTIFIC COMMITTEE Established under the Environment Protection and Biodiversity Conservation Act 1999 The Minister approved this conservation advice and included this species in the Critically Endangered category, effective from 07/12/2016 Conservation Advice Euastacus dharawalus Fitzroy Falls spiny crayfish Taxonomy Conventionally accepted as Euastacus dharawalus Morgan, 1997. Summary of assessment Conservation status Critically Endangered: Criterion 2 B1(a),(b)(v) The highest category for which Euastacus dharawalus is eligible to be listed is Critically Endangered. Species can be listed as threatened under state and territory legislation. For information on the listing status of this species under relevant state or territory legislation, see http://www.environment.gov.au/cgi-bin/sprat/public/sprat.pl Reason for conservation assessment by the Threatened Species Scientific Committee This advice follows assessment of information provided by New South Wales as part of the process to systematically review species that are inconsistently listed under the EPBC Act and relevant state and territory legislation/lists. Public Consultation Notice of the proposed amendment and a consultation document was made available for public comment for 33 business days between 28 July 2015 and 11 September 2015. Any comments received that were relevant to the survival of the species were considered by the Committee as part of the assessment process. Species Information Description The Fitzroy Falls spiny crayfish ( Euastacus dharawalus ) is a medium-sized, long-lived freshwater crayfish of the Euastacus genus. The Euastacus (spiny-shelled) and Cherax (smooth-shelled) genera form the two most specious groups of freshwater crayfish species in Australia, with Euastacus having the highest number of species, with 50 named by 2012 and this number is likely to increase (McCormack 2012). Euastacus crayfish are generally identified from other groups of Australian freshwater crayfish by having a spiny outer, often referred to as lateral, edge to their claws (McCormack 2012). Fitzroy Falls spiny crayfish are commonly olive green or green in colour, sometimes brown, on the head and back, lightening to pale orange to cream on the underside (McCormack 2012). Claws are green with yellow or orange spotting on their edges, with purple tips. Individuals grow to at least 86 mm occipital carapace length (OCL) (a standard measure unit for crayfish, which is defined as the length from between the eyes and end of main body segment) and 300 g in weight (McCormack 2012). Euastacus dharawalus (Fitzroy Falls spiny crayfish) Conservation Advice Page 1 of 12 Distribution The Fitzroy Falls spiny crayfish is only found in part of the Wildes Meadow Creek catchment, a small catchment which is a part of the Shoalhaven River catchment, a large, eastern-draining, river system which meets the sea on the south coast of New South Wales (McCormack 2012; NSW DPI 2012, McCormack 2013). Field observations from preliminary surveys undertaken between 2006 and 2011, as part of the Australian Crayfish Project, have found this species in the main creekline of Wildes Meadow Creek and in all feeder streams from the permanent water to the headwater ephemeral areas (McCormack 2013). The species is only found within the Wildes Meadow Creek catchment above Fitzroy Falls, which is an 80 m drop on the main creekline that forms a natural barrier to other, more aggressive species of freshwater crayfish, including other related species of spiny crayfish such as the widely-distributed; southern lobster (E. yanga ), and eels (Anguilla australis and A. reinhardtii ), which inhabit the creek below the falls (McCormack 2012; 2013). Surveys of the surrounding catchments have detected other species of freshwater crayfish, including the southern lobster, the giant spiny crayfish ( E. spinifer ), the hairy crayfish ( E. hirsutus ) and the translocated Murray-Darling species (the freshwater yabby, Cherax destructor ) (McCormack 2013) but not the Fitzroy Falls spiny crayfish. The naturally occurring distribution of the Fitzroy Falls spiny crayfish is limited to a stretch of approximately 12 km of waterway along Wildes Meadow Creek, of which 750 m downstream of the Fitzroy Falls Reservoir is considered high quality habitat for the species, as it is protected within the northern tip of Morton National Park (NSW DPI 2012). 3.2 km of the original creekline of Wildes Meadow Creek has been inundated by the Fitzroy Falls Reservoir, which was constructed in 1974, and surveys have indicated that the species does not inhabit the reservoir (NSW FSC pers. comm. 2015). The remainder of the waterway, upstream of the reservoir, is bordered by agricultural land (NSW FSC 2011). Since the reservoir’s construction, there are now two populations of the species isolated from each other, one below the wall and one upstream of the reservoir water. Surveys have indicated that mainly smaller (likely immature) individuals inhabit the headwater and ephemeral feeder streams of the catchment system (McCormack 2013). Relevant Biology/Ecology Fitzroy Falls spiny crayfish seem to be active at day and night with field observations indicating that peak activity is in the late afternoon and early evening (McCormack 2012). Observations have noted that burrows can be found just above or below the waterline along the earthen banks of the creek, but only the burrows below the waterline are inhabited and that individuals often wander for food outside their burrows during daylight (McCormack 2012; 2013). There is a lack of focussed research on the Fitzroy Falls spiny crayfish to enable reliable estimates of species’ longevity, average life span or generation length. However, there is a common and consistent suite of biological characteristics that apply to species in this genus. Euastacus species are generally very slow growing and long lived (between 20 to 50 years), as evidenced in other species such as the Glenelg spiny freshwater crayfish ( E. bispinosus ) (Honan & Mitchell 1995) and the blue spiny crayfish ( E. sulcatus ) (Furse & Wild 2004; Coughran 2013). Considering the Fitzroy Falls spiny crayfish occupies habitat at a reasonably high altitude (approximately 600 m above sea level), in relatively cool temperate conditions year-round, and it being a relatively large species in the genus (Coughran 2008); it is reasonable to assume that growth rates will be slow and that the species will be long-lived. Breeding starts with fertilisation in May and June, with females releasing juveniles in December (NSW FSC 2011; McCormack 2012). Recent field observations counted 512 crimson/burgundy coloured eggs on a large female individual (McCormack 2013). Euastacus dharawalus (Fitzroy Falls spiny crayfish) Conservation Advice Page 2 of 12 Threats Barriers to movement have been created by the impoundment water that is Fitzroy Falls Reservoir and the dam wall. These stop the two isolated populations of Fitzroy Falls spiny crayfish, one below the dam wall and one upstream of the reservoir, from mixing (McCormack 2013). The 3.2 km of stream length which has been inundated by the reservoir has removed habitat for the species and stops the species moving through this area. Sampling by the New South Wales Department of Primary Industries in Fitzroy Falls Reservoir has not detected the species living within its lentic habitats (NSW FSC pers. comm. 2015). Fitzroy Falls Reservoir is part of the Shoalhaven Scheme for water supply and hydro-electric power generation. Water is transferred between Lake Yarrunga, Bendeela Pondage and Fitzroy Falls Reservoir. Intake screens prevent large fish being transferred between water storages, but translocation of juvenile or small fish, including alien species, is still possible (WaterNSW pers. comm. 2015). The smaller headwater and feeder streams of the Wildes Meadow Creek catchment have rural farm dams constructed across them, limiting the available habitat area and restricting water flow (McCormack 2013). While it is unclear to what extent surveying has focussed on locating the species in these farm dams, there are as yet no definitive reports of the species occurring in the habitats that these farm dams provide (McCormack 2013). Farm dams restrict water flow in the feeder streams within the upper parts of the catchment (McCormack 2013). A desktop analysis of recent topographical and satellite imagery maps for the area counted at least 40 farm dams or impoundments within the Wildes Meadow Creek catchment upstream of Fitzroy Falls Reservoir (DoL 2006; Google Maps 2015). The presence of stream flow seems to be important to the Fitzroy Falls spiny crayfish, as surveys indicate it does not utilise lentic waters and is restricted to parts of the catchment where there are flowing stream conditions (McCormack 2013; NSW FSC pers. comm. 2015). The presence of these farm dams in the Wildes Meadow Creek catchment represents another potential threat to the species. Another potential threat to the Fitzroy Falls spiny crayfish is the damage to, or removal of, riparian vegetation. A majority of the upstream habitat area within the Wildes Meadow Creek catchment has been cleared for agriculture, and feeder streams meander through grazing paddocks (DoL 2006; McCormack 2013; Google Maps 2015). Field observations have noted that freshwater crayfish burrows, and the banks in which these occur, are being impacted by stock trampling (McCormack 2013). There are also observations of the effect of stock grazing on stream riparian