Catchment urbanisation and increased benthic algal biomass in streams: Linking mechanisms to management

Abstract

1. Urbanisation is an important cause of eutrophication in waters draining urban areas. We determined whether benthic algal biomass in small streams draining urban areas was explained primarily by small-scale factors (benthic light, substratum type and nutrient concentrations) within a stream, or by catchment-scale variables that incorporate the interacting multiple impacts of urbanisation (i.e. variables that describe urban density and the intensity of drainage or septic tank systems). 2. Benthic algal biomass was assessed as chlorophyll a density (chl a) in 16 streams spanning a rural-urban gradient, with both a wide range of urban density and of piped stormwater infrastructure intensity o..