Does land use contribute to contaminant inputs and affect habitat characteristics and biological communities in streams?
Concentrations of contaminants, such as organochlorine pesticides and polychlorinated biphenyls (PCBs) in bed sediment and whole fish tissue were related to land use. – Lowest concentrations and fewest number of these compounds were measured in forested mountains or rangeland sites; highest concentrations and greatest number of compounds were measured in urban and mixed (urban/agriculture) areas. A habitat degradation index (HDI) and an index of biotic integrity (IBI), indicates that most sites were moderately degraded and that human activities and local site characteristics had a greater effect on habitat and fish communities than basin-scale characteristics such as land use. The relative abundance of families of fish were altered and the number of invertebrate taxa were lower in mining-affected sites and urban, agricultural and mixed land-use settings compared to minimally affected areas such as forest and rangeland.
