Figure 1.
A severe hypoxic blackwater event resulted in extensive fish kills in the Murray-Darling Basin, Australia in 2010/11.
Photograph shows a Murray cod Maccullochella peelii (Mitchell) appearing to perform aquatic surface respiration (ASR) during the hypoxic blackwater event in the Edward River near Moulamein, New South Wales. Printed under a CC BY license with permission from L. Pearce, 2011.
Table 1.
Mean body size measurements and water quality parameters for hypoxia experiments conducted on Murray-Darling Basin fishes.
Figure 2.
Lethal oxygen concentrations of four Murray-Darling Basin fishes.
Proportion of juvenile Murray cod Maccullochella peelii (Mitchell), golden perch Macquaria ambigua (Richardson), silver perch Bidyanus bidyanus (Mitchell) and eel-tailed catfish Tandanus tandanus (Mitchell) dead at different dissolved oxygen concentrations at 25–26°C. Solid black and dashed green lines represent significant (P<0.05) logistic regressions fitted to simulated hypoxic blackwater and hypoxic freshwater experiments respectively. Circles represent model predicted values.
Table 2.
Generalised Linear Mixed Model (GLMM) estimates ±SE combining all factors to predict mortality and aquatic surface respiration (ASR) responses of four Murray-Darling Basin fishes exposed to hypoxic freshwater and simulated blackwater.
Table 3.
Logistic function parameters predicting lethal concentrations (LC) of dissolved oxygen (DO) in four Murray-Darling Basin fishes.
Table 4.
Mortality (%) of four Murray-Darling Basin fishes exposed to simulated blackwater experiments and confirmed mortalities associated with natural hypoxic blackwater events in the Edward-Wakool river system in 2010/11.
Figure 3.
Aquatic Surface Respiration (ASR) in four Murray-Darling Basin fishes.
Proportion of juvenile Murray cod Maccullochella peelii (Mitchell), golden perch Macquaria ambigua (Richardson), silver perch Bidyanus bidyanus (Mitchell) and eel-tailed catfish Tandanus tandanus (Mitchell) performing ASR at different dissolved oxygen concentrations at 25–26°C. Solid black and dashed green lines represent significant (P<0.05) logistic regressions fitted to simulated hypoxic blackwater and hypoxic freshwater experiments respectively. Circles represent model predicted values.
Table 5.
Logistic function parameters predicting the proportion of live fish performing aquatic surface respiration (ASR) over 48 hrs at different dissolved oxygen (DO) concentrations.