Macroecology of fish community biomass-size structure: effects of invasive species and river regulation

The biomass of organisms of different sizes is increasingly being used to explore macro-scale variation in food-web and community structure. Here we examine how invasive species and river flow regulation affect native fish biomass and fish community log10 biomass-body mass scaling relationships in Australiaâ s largest river system, the Murray-Darling. The log10 biomass-body mass scaling exponent (scaling B) of invasive fishes (95% CI; -0.14 to -0.18) was less negative than for native fishes (95% CI; -0.20 to -0.25), meaning that invasive species attained a higher biomass in larger size-classes compared to native species. Flow alteration and invasive common carp (Cyprinus carpio) biomass were correlated with severe reductions in native fish biomass ranging from -47% to -68% (95% CI). Our study provides novel evidence suggesting that invasive and native communities have different biomass-body mass scaling patterns, which likely depend on differences in their trophic ecology and body size distributions. Our results suggest that restoration efforts using environmental flows and common carp control has potential to boost native fish biomass to more than double the current level.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author