The Influence of the Type of a Small Watercourse on the Degree and Direction of Disturbance of Macrozoobenthos during Road Works in Swampy Taiga Conditions

Abstract The construction of bridges and other culverts during road construction is a common cause of disturbance to riverine ecosystems. Small streams are particularly vulnerable. The impact of such work on the composition and abundance of macrozoobenthos is examined using streams—tributaries of the Kem River (White Sea basin) as an example. A study of changes in the abundance, biomass, and composition of benthic invertebrates in the road reconstruction zone was conducted in September 2022 and 2023 at nine small streams. In all cases, a decrease in biodiversity indicators—the Shannon and Simpson indices, and the number of species detected per sample—was observed. The abundance and biomass of macrozoobenthos varied depending on the nature of the stream—the predominant bottom substrate in the background area. In streams with detrital bottoms, the total abundance increased (primarily due to the larvae of Chironomidae—chironomids), while in rivers with rocky bottoms, it decreased.