Murray crayfish rescue in Edward River

Australia is home to over 100 crayfish (McCormack, 2012). Many of them are considered as threatened. Recent flooding in late 2022 in the Murray-Darling Basin has caused several instances of ‘hypoxic blackwater’ (low oxygen water) that negatively impacts certain aquatic animals, such as Murray Crayfish (Euastacus armatus). Murray Crayfish is a large and iconic species in Australia. At multiple locations Murray crayfish “walked” out of the water in high numbers in different parts of the Murray River and its tributaries, including the Edward River. The Inland Fisheries Research Group from the Gulbali Institute of Charles Sturt University worked together with the Edward-Wakool Angling Association (EWAA) and the Joint Indigenous Group (JIG) rescued a total of 115 Murray crayfish from the Edward River. These were rescued from three distinct sites along the Edward River: 42 from the Boat Club, 33 from Twin Rivers, and 40 from the 4-post (Figure 1). Unfortunately, eight crayfish died during storage before being transported to the laboratory. The Murray crayfish were then transported to the Aquatic Laboratory of the Charles Sturt University for safekeeping until water quality improved. They varied in weight (body weight: 75 – 1100 g) and size (occipital carapace length: 40 – 135 mm). Funding for the rescues was provided by the Murray Darling Basin Authority with logistical and permitting support from NSW DPI – Fisheries.