As above As above Age of golden Golden perch that recruited to the perch lavae lower River Murray in 2012 were and generally not spawned in year (YOY) association with the delivery of Commonwealth environmental Spatial origin water to the lower Murray channel. of golden Nevertheless, substantial volumes perch lavae (4,000–5,000 ML d-1) of and YOY using environmental water delivered otolith down the Darling River from chemistry January–February 2012 would have aided the downstream dispersal of early life stage golden perch spawned in the Darling and the subsequent recruitment of these fish in the lower Murray Salt and Increased flows Salt transport A significant reduction in salinity – will transport salt nutrient Lock 1 to levels in the Northern Coorong. The through the transport and Southern greatest influence was observed River Murray export (water Ocean during February 2012, with and export the quality and modelling suggesting that salinity salts from the nutrient was reduced by up to 70% in the system, cycling) Northern Coorong) providing Nutrient sufficient flow transport – Increased export of salt and out of the Lock 1 to Murray Mouth particulate organic nutrients to the Southern Southern Ocean associated with Increased flows Ocean environmental water releases, will transport which were associated with nutrients through elevated outflows through the the River Murray, Murray Mouth and reduced Lower Lakes and By Coorong, seawater incursions. The greatest stimulating influence was observed during model primary February 2012, with modelling productivity suggesting that environmental water accounted for 70% of the total salt exports and 50% of the particulate organic nutrient exports from the Murray Mouth 1b. Summary of larval fish reponses to high flow years including 2011-12 watering year.
As above As above Age of golden perch lavae and (YOY) Spatial origin of golden perch lavae and YOY using otolith chemistry Golden perch that recruited to the lower River Murray in 2012 were generally not spawned in association with the delivery of Commonwealth environmental water to the lower Murray channel. Nevertheless, substantial volumes (4,000–5,000 ML d-1) of environmental water delivered down the Darling River from January–February 2012 would have aided the downstream dispersal of early life stage golden perch spawned in the Darling and the subsequent recruitment of these fish in the lower Murray Salt and nutrient transport and export (water quality and nutrient cycling) Increased flows will transport salt through the River Murray and export the salts from the system, providing sufficient flow out of the Murray Mouth Increased flows will transport nutrients through the River Murray, Lower Lakes and Coorong, stimulating primary productivity Salt transport – Lock 1 to Southern Ocean Nutrient transport – Lock 1 to Southern Ocean By model A significant reduction in salinity levels in the Northern Coorong. The greatest influence was observed during February 2012, with modelling suggesting that salinity was reduced by up to 70% in the Northern Coorong) Increased export of salt and particulate organic nutrients to the Southern Ocean associated with environmental water releases, which were associated with elevated outflows through the Murray Mouth and reduced seawater incursions. The greatest influence was observed during February 2012, with modelling suggesting that environmental water accounted for 70% of the total salt exports and 50% of the particulate organic nutrient exports from the Murray Mouth 1b. Summary of larval fish reponses to high flow years including 2011-12 watering year. year
ecological-response-monitoring-murray-11-12-final-report.docx