caa a22 4500 477116418 CHVBK 20180405111623.0 cr unu---uuuuu 170330e19960901xx s 000 0 eng 10.1007/BF00002376 doi (NATIONALLICENCE)springer-10.1007/BF00002376 Drought, differential mortality and the coexistence of a native and an introduced fish species in a south east Australian intermittent stream [Elektronische Daten] [Gerard Closs, P. Lake] Synopsis: The longitudinal distribution ofSalmo trutta andGalaxias olidus, a small salmoniform fish, was mapped over four summers (1985-1988) in the upper reaches of the Lerderderg River, an intermittent stream in central Victoria. Over the four successive summers of the study, the distribution ofS. trutta expanded upstream. Coincident with the expansion ofS. trutta was a contraction in the distribution ofG. olidus upstream. In the summer of 1988, an extended dry spell resulted in high levels ofS. trutta mortality at the upstream limits of their distribution. This suggested that the upstream distribution ofS. trutta could ultimately be constrained by an inability to tolerate prolonged periods of low stream flow and high temperatures that tended to occur in the headwaters of the stream. A study of summer mortality was conducted over three successive summers (1989-1991) at three reaches along the river. The two downstream reaches contained onlyS. trutta, the upstream reach contained bothS. trutta andG. olidus. Salmo trutta mortality was consistently higher at the most upstream reach compared with lower reaches. High levels ofS. trutta mortality at the two downstream reaches were only observed in 1991, a particularly dry year. In contrast,G. olidus survived in scattered small pools throughout the upper reaches of the stream. The results of the study suggest a shifting pattern ofS. trutta andG. olidus distribution determined by the duration of low stream flow periods and summer high temperatures. Kluwer Academic Publishers, 1996 Trout nationallicence Salmo trutta nationallicence Galaxiidae nationallicence Galaxias olidus nationallicence Lotic fish nationallicence Biotic interactions nationallicence Longitudinal zonation nationallicence Closs Gerard Department of Ecology and Evolutionary Biology, Monash University, 3168, Clayton, Victoria, Australia aut Lake P. Department of Ecology and Evolutionary Biology, Monash University, 3168, Clayton, Victoria, Australia aut Environmental Biology of Fishes Kluwer Academic Publishers; http://www.wkap.nl 47/1(1996-09-01), 17-26 0378-1909 47:1<17 1996 47 10641 https://doi.org/10.1007/BF00002376 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00002376 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Closs Gerard Department of Ecology and Evolutionary Biology, Monash University, 3168, Clayton, Victoria, Australia aut NATIONALLICENCE 700 1- Lake P. Department of Ecology and Evolutionary Biology, Monash University, 3168, Clayton, Victoria, Australia aut NATIONALLICENCE 773 0- Environmental Biology of Fishes Kluwer Academic Publishers; http://www.wkap.nl/ 47/1(1996-09-01), 17-26 0378-1909 47:1<17 1996 47 10641 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer