The Effect of Small River Fragmentation on the Biodiversity and Structure of Macroinvertebrate Communities

Nikola Petković1, Nataša Radojković1, Ana Petrović1

 

 

1 University of Kragujevac, Faculty of Science, Department of Biology and Ecology, Radoja Domanovića 12, 34000 Kragujevac, Serbia;  E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

 

 

Abstract

Aquatic ecosystem fragmentation is caused by the damming of waterways. The object of this study was the Grošnica River in Central Serbia. In 1937 a dam was raised on this small river in order to create water accumulation, while during 1965 a series of weirs were built on its upper course to reduce erosion. The aim of this study was to determine the qualitative composition and condition of the macroinvertebrates community based on the results of the research conducted during 2011-2013, and to compare them with the results obtained in the study from 1973 on the same river. The results have shown that there were no greater changes in composition of macroinvertebrate community of the Grošnica River over a period of forty years.

Keywords: macroinvertebrate community, fragmentation, Grošnica River, Serbia.

 

Introduction

Habitat fragmentation causes the occurrence of many smaller parts due to various anthropogenic activities. Fragmentation decrease species colonization potential by preventing their migration and dispersion (Milankov, 2007). Aquatic ecosystem fragmentation caused by dam building leads to water quality decrease and habitat alteration, and it also prevents fish and invertebrate migration (Santucci et al., 2005).

Biodiversity and species distribution in aquatic ecosystems depend on many environmental factors such as; bottom structure, depth, stream speed, exposition etc. These factors are of great importance for the existence of many benthic macroinvertebrate species. Strong and long-lasting changes of these conditions can provoke the extinction of those species.

Human impact is one of the factors that changes the conditions in river streams causing biocenosis changes and sensitive species extinction (Viðinskienë, 2005).

The Grošnica River belongs to the Black Sea drainage, and it is Danube's rank III tributary. It is the right tributary of the Lepenica River, 18 km long. In 1937 an accumulation was built in the middle of the river to serve as a water supply for the City of Kragujevac. Because of the large amount of material sedimentation on the dam, a series of small floodgates on the upper stream of the river were built in order to slow down erosion.

The goal of this study was to determine the influence of small river fragmentation to the macroinvertebrate community, using the Grošnica River as an example during a 40 year time span, by comparing results of the two studies conducted during 1973 and during the 2011-2013 time period.