Silver perch (Bidyanus bidyanus) Moderate to long-lived 8 years in 10 Australia ACT, NSW, Vic, SA, Qld Formerly a recreational species but take is now restricted due to threatened status. Heavily impacted channel specialist. Flow-cued spawning. Flows govern recruitment strength in this species, with spawning and recruitment enhanced by spring/summer flooding and high within-channel flow pulses. Spawn and recruit in flowing habitats. Flows stimulate movement of both adults and juveniles. Large-scale movement requirements that are interrupted by loss of flows and barriers to connectivity: flows (current velocity) disperse early life stages (larval drift) large scale spawning migrations. Southern & Northern Basin Golden Perch (Macquaria ambigua) Moderate to long-lived 8 years in 10 No (but a no-take population in Vic) Key recreational target species. Important economic asset. Impacted channel specialist. Flow-cued spawning. Flows govern recruitment strength in this species, with spawning and recruitment enhanced with spring/summer flooding and high within-channel flow pulses. Spawn and recruit in flowing habitats Flows stimulate movement Flows (current velocity) disperse early life stages. Golden perch have more flexibility in spawning and recruitment than silver perch. Southern & Northern Basin Murray cod (Maccullochella peelii peelii) Moderate to long-lived 8 years in 10 Australia Vic, SA Iconic species. Key recreational target species & key economic asset. High importance to aboriginal peoples. Formerly a commercial species before fishery declined. Heavily impacted channel specialist. Large-scale movements that are critical in the life-cycle (e.g. spawning migrations and larval drift) are interrupted by loss of flows and barriers to connectivity. Requires access to fast and moderate flowing in-channel habitat of good quality. Spawn and recruit in flowing habitats—loss of these habitats has major impacts on this species. Seasonally appropriate flows (with rising water levels) are required to stimulate migration. Flows also increase productivity and available habitat. Highly impacted by blackwater events—flow is important to maintain water quality. Spawning is independent of flooding but recruitment can be enhanced by elevated flows. Nesting species that requires stable water depths for the duration of nesting to ensure adults do not abandon nests. Requires flowing water during this time period to maintain water quality. Flow (current velocity) then disperses larval stages. Southern & Northern Basin
Table Important Basin environmental assets for native fish Environmental asset Key movement corridors High Biodiversity Site of other Significance Key site of hydrodynamic diversity Threatened species Dry period / drought refuge Southern Basin Coorong, Lower Lakes and Murray Mouth * * * * * Swamps on the lower Murray channel, between Wellington and Mannum (swamp geomorphic region) * * Kerang Lakes * * Katarapko anabranch * * Pike anabranch * * Lower River Murray main channel (from Darling junction downstream) * * * * * Murray main channel (from Hume dam to Darling junction) * * * * * * Chowilla anabranch * * * * * * Lindsay–Walpolla–Mularoo Creek * * * * * * Lower Darling main channel * * * * * *