Paolo Espa

Response of stream benthic macroinvertebrates to current water management in Alpine catchments massively developed for hydropower

The present work focuses on evaluating the ecological effects of hydropower-induced streamflow alteration within four catchments in the central Italian Alps. Downstream from the water diversions, minimum flows are released as an environmental protection measure, ranging approximately from 5 to 10% of the mean annual natural flow estimated at the intake section. Benthic macroinvertebrates as well as daily averaged streamflow were monitored for five years at twenty regulated stream reaches, and possible relationships between benthos-based stream quality metrics and environmental variables were investigated. Despite the non-negligible inter-site differences in basic streamflow metrics, benthic macroinvertebrate communities were generally dominated by few highly resilient taxa. The highest level of diversity was detected at sites where upstream minimum flow exceedance is higher and further anthropogenic pressures (other than hydropower) are lower. However, according to the current Italian normative index, the ecological quality was good/high on average at all of the investigated reaches, thus complying the Water Framework Directive standards.

Water Management and Related Environmental Issues in Large Mediterranean Basins: Case Studies from the Ebro and the Po Catchments

Water exploitation for hydropower and irrigation alters the natural hydrologic regime of rivers, and consequently instream biocenosis and ecological processes. The identification of management decisions able to protect freshwater ecosystems while maintaining important water uses is a crucial issue for both science and management. This study presents and compares water management schemes into two large Mediterranean river basins. Environmental issues linked to management are discussed taking into account different local features and the regulatory framework.