Aquatic Ecosystems of Arid and Semi-Arid Regions
Morrongiello, J.R., Crook, D.A., King, A.J., Ramsey, D.S. and Brown, P. 2011. Impacts of drought and predicted effects of climate change on fish growth in temperate Australian lakes. Global Change Biology 17: 745-755.
Noting that such warmer and drier conditions "can already be found today in areas experiencing significant drought," the five researchers analyzed the width of the yearly growth increments laid down in the otoliths (earstones) of populations of a native fish species (the golden perch) living in two artificial impoundments (Lakes Mokoan and Eppalock) near their southerly distribution limits in central Victoria, Australia, over a 15-year period that both pre-dated and encompassed a significant supra-seasonal drought.
Morrongiello et al. determined from their analysis that "fish growth declined as water levels in the lakes dropped during the drought," but they say that "this effect was offset by increased growth in warmer years." In fact, it was more than offset; because based on the relationships they developed from their real-world data, they found that the 2070 mean annual growth of two-year-old golden perch in Lakes Mokoan and Eppalock, respectively, was estimated to increase by 14.9% and 17.2% under low CO2emission and 56.5% and 58.6% under high CO2emission scenarios compared with 1990 CO2levels.
In discussing their findings, the Australian scientists conclude that "despite climatic models predicting significant declines in future water availability, fish growth may increase due to a disproportionate lengthening of the growing season." Thus, they predict that "golden perch growth rates in southerly [Australian] populations may increase as warmer conditions associated with climate change will lengthen the growing season and make these high [southern] latitude habitats more favorable."
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Lake, P.S. 2003. Ecological effects of perturbation by drought in flowing waters. Freshwater Biology 48: 1161-1172.