Freshwater Mussels of the Serbian Stretch of the Tisa River

Jelena Tomović¹, Vladica Simić², Bojana Tubić¹, Katarina Zorić¹, Margareta Kračun¹, Vanja Marković¹, and Momir Paunović¹

 

 

¹ University of Belgrade, Institute for Biological Research "Siniša Stanković", Despota Stefana 142, 11000 Belgrade, Serbia; E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

² University of Kragujevac, Institute of Biology and ecology, Faculty of Science, Radoja Domanovića 12, 34000 Kragujevac, Serbia

 

Abstract

This paper provides a list of recorded taxa and discusses the distribution and relative abundance of freshwater mussels (Bivalvia: Unionoida: Unionidae) along the Serbian stretch of the Tisa River. The objective of the work is to contribute to the general knowledge about the distribution and autecological characteristic of the species that could play a part in more effective assessment of ecological status. The results are especially interesting because Mollusca were found to be one of the principal components of the macroinvertebrate community in the lowland rivers. During the investigation six species of mussels were recorded. The most abundant and frequent species were found to be Unio pictorum (Linnaeus, 1758) and Unio tumidus (Philipsson, 1788).

Keywords: Unionoida, Tisa River, community structure

 

Introduction

 

This work is a part of a research aimed to contribute to the better knowledge on freshwater mussels, or unionids (Bivalvia: Unionoida: Unionidae). According to the EU Water Framework Directive (WFD, 2000), ecological status assessment of water bodies are primarily based on analyses of aquatic communities – Biological Quality Elements (BQEs), including mollusks as one of the most important component in large lowland rivers (in regards to number of recorded species, relative abundance and biomass) in the Danube Basin (Graf et al., 2008; Paunović et al., 2007, 2012; Tomović et al., 2010; 2012; Tubić et al., 2013). Further, freshwater mussels represent one of the most of severely endangered groups of animals due to habitat degradation, pollution pressure and introduction of alien species. Thus, the aim of this paper is to present the data needed to contribute to the knowledge of the unionids community and its use in ecological status assessment.

Study area

The Tisa Sub-Basin is the largest sub-basin of the Danube Basin. The basin area is shared by five countries (Ukraine, Slovakia, Romania, Hungary, and Serbia). The lower, 160 km-long course of the Tisa (16.6% of the length of its main stream) is located within the territory of Serbia. The Tisa River comes from Hungary and reaches the Danube in Serbia, near Slankamen (at rkm 1215). Here only 5% of its catchments area is on the territory of Serbia, and this stretch has the typical characteristics of a lowland river (lower Tisza). In this sector, the river receives the Begej River and some smaller tributaries indirectly through the Danube-Tisza-Danube Canal System (HS DTD).

The Tisa River Basin in Serbia is under the influence of various stressors (Vasiljević et al., 2010; Kolarević et al., 2011) - pollution (organic, nutrient, wastewater from industrial facilities and agricultural activities) and hydromorphological degradation (cutting of the meanders, shortening, channeling, as well as gravel and sand extraction). The investigated part of the river is under the influence of untreated urban waste waters, as well as the sugar and fermentation industry wastes (Senta municipality) and effluents of the paper and cardboard industry (Novi Kneževac).

Water quality of the Tisa River was assessed as good to moderate (class II-III) based on the results of a macroinvertebrates survey (Simonović et al., 2010).

 

Material and Methods

The study is based on the results of investigation of freshwater mussels (order Unionoida) in the Serbian part of the Tisa River during the period from 2001 to 2012. Investigation was conducted on five sampling sites along the Tisa River (Figure 1, Table 1).

 

Fig1
Figure 1: Sampling sites along the Tisa River

 

Table 1: Sampling sites on the Tisa River
Tab1

 

Samples were collected by benthic hand nets and free diving. The coordinates of the sampling points were measured by GPS ("Garmin Etrex") and charted by using ArcView software (map 1:300,000, system WGS_1984). The analysis of autecological characteristics (AQEM 2002) was performed and discussed. Relative abundance was evaluated according to the scale presented in the Table 2.

 

Table 2: Scale used for the relative abundance assessment
Tab2