Lake Eyre Basin Rivers 48 species can complete their life histories within isolated waterholes during dry periods when there are no channel flows these include yellowbelly, bony bream, spangled perch, carp gudgeons, rainbowfish and glassfish (Table 4.1). These opportunistic species can maintain recruitment or replace their populations in isolated waterholes irrespective of season, channel flows or floods, but if channel flow or flood events occur, new recruits are available to disperse or colonise newly available habitat (Balcombe and Arthington 2009 Kerezsy et al. 2011 Cockayne et al. 2015). Three fish species have a seasonal recruitment strategy. Australian smelt probably commence spawning in mid to late winter (July–August) in the Cooper Creek catchment when the timing of breeding is linked with seasonal temperature cues rather than flow conditions. Summer-cued recruitment is characteristic of silver tandan and Cooper Creek catfish. These species breed on an annual cycle, with spawning occurring in early summer, and spawning events take place irrespective of antecedent hydrology and flow conditions (Balcombe and Arthington 2009 Kerezsy et al. 2011). The remaining species are either dependent on, or heavily influenced by, the occurrence of channel flows or flooding (Hyrtl’s tandan, Barcoo grunter and Welch’s grunter). Recruitment of Hyrtl’s tandan in Cooper Creek and other Lake Eyre Basin rivers is triggered by major flooding (Balcombe and Arthington 2009 Kerezsy et al. 2011). Similar recruitment patterns have been reported in populations of Hyrtl’s tandan from the Murray–Darling Basin (Balcombe et al. 2006). Three members of the Cooper Creek fish fauna (yellowbelly, spangled perch and glassfish) show particularly flexible breeding patterns by spawning when there is no flow as well as demonstrating flow-related recruitment. Fig. 4.2. Catching fish using fyke nets in a waterhole of the Mulligan River in the Georgina River catchment of the Lake Eyre Basin (photo, A. Kerezsy).
Previous Page Next Page