engleski

Destructive effect of quarry effluent on life in a mountain stream

Quarrying is a widespread method for acquiring construction material. The studies of quarrying effects to date have been conducted mostly in the fields of geology, (hydro) geochemistry and landscape management while ecological studies on effects of quarrying are surprisingly few. The goal of this study was to assess some ecological effects of quarry mining on mountain stream habitats. The study was performed at Bistra stream on Medvednica Mountain in NW Croatia. The quarry is located 3 km downstream from the spring. Samples were taken at four sites on four dates during the spring of 2006. Standard physico chemical parameters were measured and triplicate benthos samples were taken using a 30 × 30 cm Surber sampler. Turbidity, pH and temperature increased significantly downstream of the quarry. All biocenotic descriptors decreased significantly downstream of the quarry including total taxa (by 60%), total number of individuals (by 85%), diversity index (by 56%). The most important cause of such changes in the macroinvertebrate assemblage structure was the change in pH and turbidity. The magnitude of changes in the macroinvertebrate assemblage structure was due to the extremely long duration of disturbance. However, we believe that the recovery of aquatic assemblages, upon closure of the quarry, would be fast and successful because of nearby streams that may serve as a recolonizing source.

quarry; fine sediment; mining; macroinvertebrates; disturbance; stream; Croatia

nije evidentirano