Category 1. Did the estimated biomass of In contrast to relative abundance, there was a decrease in the ratio (total biomass) of common Fish (channel) common carp in the Gorge zone carp to flow-dependant, native species (golden perch and silver perch) at four of the five sites # increase during the current year, sampled in autumn 2017, relative to the previous year. In 2017, the site where the estimated biomass relative to the previous year, of carp increased at a greater rate than flow-dependant, native species was Overland Corner A. whilst the estimated biomass of During 2016, the mean site ratio was 2.10 kg of carp (± 0.65 S.E.) to every 1 kg of flow-dependant, flow-dependent native species native species. In 2017, this ratio decreased to 1.48 kg of carp (± 0.33) to every 1 kg of decreased?* native species. Category 1. What did CEW contribute to In 2016/17 a substantial high flow event provided a seasonal hydrograph that encompassed Hydrology providing a seasonal variation in discharge, velocity and water levels. Environmental water supplemented this event by (channel) hydrograph that encompassed reducing the recession in water levels in the order of 0.7–0.9 m and resulted in an increase variability variation in discharge, velocity in lower flows over the first six months of 2017. and water levels? Category 3. What did CEW contribute to Environmental water provided on the flood recession slowed the reduction in velocity during Hydrological providing diverse hydraulic January. After this event, environmental water increased weir pool median velocities to a small Regime conditions and complex habitat degree (0.05 – 0.07 m s-1), with some sections of the river being greater than 0.17 m s-1, particularly for flow dependant biota and during an event in March. processes?
Category 1. Fish (channel) # Did the estimated biomass of common carp in the Gorge zone increase during the current year, relative to the previous year, whilst the estimated biomass of flow-dependent native species decreased?* In contrast to relative abundance, there was a decrease in the ratio (total biomass) of common carp to flow-dependant, native species (golden perch and silver perch) at four of the five sites sampled in autumn 2017, relative to the previous year. In 2017, the site where the estimated biomass of carp increased at a greater rate than flow-dependant, native species was Overland Corner A. During 2016, the mean site ratio was 2.10 kg of carp (± 0.65 S.E.) to every 1 kg of flow-dependant, native species. In 2017, this ratio decreased to 1.48 kg of carp (± 0.33) to every 1 kg of native species. Category 1. Hydrology (channel) What did CEW contribute to providing a seasonal hydrograph that encompassed variation in discharge, velocity and water levels? In 2016/17 a substantial high flow event provided a seasonal hydrograph that encompassed variation in discharge, velocity and water levels. Environmental water supplemented this event by reducing the recession in water levels in the order of 0.7–0.9 m and resulted in an increase variability in lower flows over the first six months of 2017. Category 3. Hydrological Regime What did CEW contribute to providing diverse hydraulic conditions and complex habitat for flow dependant biota and processes? Environmental water provided on the flood recession slowed the reduction in velocity during January. After this event, environmental water increased weir pool median velocities to a small degree (0.05 – 0.07 m s-1), with some sections of the river being greater than 0.17 m s-1, particularly during an event in March.