Multiscale effects of flow regime and habitat and their interaction on fish assemblage structure in eastern Australia

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Author(s)
Kennard, Mark J
Olden, Julian D
Arthington, Angela H
Pusey, Bradley J
Poff, N LeRoy
Year published
2007
Metadata
Show full item recordAbstract
We examine the multiscale influence of environmental and hydrological features of the riverine landscape on spatial and temporal variation in fish assemblages in eastern Australia. Multiresponse artificial neural network models provided accurate predictions of fish assemblages in the Mary River based on species presence-absence data (mean Bray-Curtis similarity between predicted and observed composition = 84%) but were less accurate when based on species relative abundance or biomass (mean similarity = 62% and 59%, respectively). Landscape- and local-scale habitat variables (e.g., catchment area and riparian canopy cover) ...
View more >We examine the multiscale influence of environmental and hydrological features of the riverine landscape on spatial and temporal variation in fish assemblages in eastern Australia. Multiresponse artificial neural network models provided accurate predictions of fish assemblages in the Mary River based on species presence-absence data (mean Bray-Curtis similarity between predicted and observed composition = 84%) but were less accurate when based on species relative abundance or biomass (mean similarity = 62% and 59%, respectively). Landscape- and local-scale habitat variables (e.g., catchment area and riparian canopy cover) and characteristics of the long-term flow regime (e.g., variability and predictability of flows) were more important predictors of fish assemblages than variables describing the short-term history of hydrological events. The relative importance of these variables was broadly similar for predicting species occurrence, relative abundance, or biomass. The transferability of the Mary River predictive models to the nearby Albert River was high for species presence-absence (i.e., closer match between predicted and observed data) compared with species abundances or biomass. This suggests that the same landscape-scale features are important determinants of distribution of individual species in both rivers but that interactions between landscape, hydrology, and local habitat features that collectively determine abundance and biomass may differ.
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View more >We examine the multiscale influence of environmental and hydrological features of the riverine landscape on spatial and temporal variation in fish assemblages in eastern Australia. Multiresponse artificial neural network models provided accurate predictions of fish assemblages in the Mary River based on species presence-absence data (mean Bray-Curtis similarity between predicted and observed composition = 84%) but were less accurate when based on species relative abundance or biomass (mean similarity = 62% and 59%, respectively). Landscape- and local-scale habitat variables (e.g., catchment area and riparian canopy cover) and characteristics of the long-term flow regime (e.g., variability and predictability of flows) were more important predictors of fish assemblages than variables describing the short-term history of hydrological events. The relative importance of these variables was broadly similar for predicting species occurrence, relative abundance, or biomass. The transferability of the Mary River predictive models to the nearby Albert River was high for species presence-absence (i.e., closer match between predicted and observed data) compared with species abundances or biomass. This suggests that the same landscape-scale features are important determinants of distribution of individual species in both rivers but that interactions between landscape, hydrology, and local habitat features that collectively determine abundance and biomass may differ.
View less >
Journal Title
Canadian Journal of Fisheries and Aquatic Sciences
Volume
64
Copyright Statement
© 2007 NRC Research Press. The attached file is reproduced here in accordance with the copyright policy of the publisher. Please refer to the journal's website for access to the definitive, published version.
Subject
Ecology
Zoology
Fisheries sciences