Euastacus dharawalus is NSW’s rarest spiny crayfish species and in 2006 the Australian Crayfish Project identified an additional threat of significance to this species. Euastacus dharawalus is only found in one small stream (Wildes Meadow Creek) roughly 11 km long above Fitzroy Falls. The Falls is an 80 m straight drop and we surmise that E. dharawalus is just a remnant population isolated from all the other species in the surrounding area by the barrier of the falls.
A water supply reservoir was constructed on this small creek as part of the supply of drinking water to Sydney. This huge reservoir on the tiny creek has significantly altered the hydrology of the area and impacted on the states rarest spiny crayfish. Now, to exasperate the problem an invasive crayfish species The Yabby Cherax destructor has been introduced to the area and it has gone forth and multiplied creating an ongoing and growing threat to the endemic Euastacus dharawalus.
We arrived on site just on dark and set up camp as the first priority whilst there is light. Were in far northern NSW near the Qld border in the drainage of the Clarence River.
New Year’s eve 2010 was spent up the mountains in Nundle and Tuggolo State Forests about 250km north of Sydney. These are forests along the top of the Great Divide around the 1200 to 1300mtrs high which is pretty high for Australian Mountains. A few months ago in spring when we were last here it was snowing but now its summer and its cool but sunny and dry. The forests are a mixture of native eucalypts and plantation pines. The pine areas are easily accessible but much of the native forest in only accessed by long distance hikes.
As part of the Australian Crayfish Project (ACP) we are researching a high altitude Euastacus crayfish species that is only found in the streams above 1000m in this section of the Great Divide. Euastacus gamilaroi is a small crayfish that is found on both sides of the Great Divide and that’s a bit unusual as most species are usually on one side or the other.
(Any fauna that lives in a groundwater system)
Blind Syncarids, Isopods, Amphipods, Gastropods & Beetles
Near Narrabri NSW is Maules Creek, it is a semi arid region in the area from the base of the Nandewar Range (Mt Kaputar) to the Namoi River and I was out there to survey the creeks draining this area for freshwater crayfish. Whilst there I met up with Peter Serov. Peter is into all things aquatic with a particular passion for Groundwater Dependent Ecosystems (GDEs). This was all new to me so I teamed up with Peter and I helped him with his groundwater surveying in the area and he helped me with my creek surveys.
Over Xmas 2010 as part of the Australian Crayfish Project (ACP) we were surveying coastal NSW for the Northern
Coastal Yabby (Cherax cuspidatus). This expedition was from Bonny Hills to Harrington, NSW.