Indicative Ecological Status Assessment of the Južna Morava River Based on Aquatic Macroinvertebrates

Boris Novaković1

 

 

1 Serbian Environmental Protection Agency, Ministry of Energy, Development and Enviromental Protection, Ruže Jovanovića 27a, Belgrade, Serbia; E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

 

Abstract

The paper presents the results of the study on  the quality of Južna Morava water, based on the analysis of aquatic macroinvertebrate community.  Investigations were performed in June and September 2011. The sampling area covered five sites: Mojsinje, Aleksinac, Grdelica, Vladičin Han and Ristovac. The following metrics were used: Saprobic Index (Zelinka & Marvan), BMWP (Biological Monitoring Working Party) Score, ASPT (Average Score Per Taxon), number of Ephemeroptera, Plecoptera, Trichoptera (EPT) taxa, total number of taxa and Shannon-Weaver Diversity Index for the assessment of the ecological status.  Based on analyses of selected parameters, the indicative ecological status of the Južna Morava River in the investigated stretch could be assessed as moderate (Class III). A total of 83 aquatic invertebrate taxa were recorded. With respect to the taxa richness, the dominant taxa were found to be Ephemeroptera, Trichoptera and Gastropoda. With regard to the relative abundance/percentage participation, Trichoptera, Hirudinea and Gastropoda were recorded as principal components of the macroinvertebrate community.

Keywords: aquatic macroinvertebrate community, Južna Morava River, water quality parameters, indicative status assessment

 

Introduction

 

The paper states conclusions about the water quality of the Južna Morava River based on the analyses of aquatic macroinvertebrate community. The results of qualitative, quantitative as well as saprobiological analyses were included in the study.

The Južna Morava River is 295 km long and it begins in the mountain of Skopska Crna Gora in Macedonia. Its own catchment area is 15,469 km² and average discharge at the mouth is 100 m³/s. Streams of Ključevska and Slatinska reka join together to form the river Golema, which is, after passing the Macedonian-Serbian border, known as the Binačka Morava. After 49 km it meets the Preševska Moravica at Bujanovac, and for the remaining of 246 km flows as the Južna Morava. It flows generally in the south to north direction, from the Macedonian border to Central Serbia, where it meets the Zapadna Morava River at Stalać, to create the Velika Morava River. The Južna Morava has 157 tributaries. The most important left ones are: Jablanica, Veternica, Pusta reka and Toplica. Right tributaries are: Vrla, Vlasina, Nišava (the longest) and Sokobanjska Moravica.

The Serbian stretch of the Južna Morava River covers six water bodies (Official Gazette of the R. of Serbia 96/2010), and four of them are situated within the investigated area: JMOR_1, JMOR_2, JMOR_4 and JMOR_6.

According to the national typology of surface waters, the Južna Morava River belongs to Type 2 - large rivers with medium grain-size mineral substrates, except Pannonian plain rivers (Official Gazette of the R. of Serbia 74/2011). With regard to ecoregions delineation for the territory of Serbia, the Južna Morava River belongs to Ecoregion 5 (ER5) (Paunović et al., 2012).

Material and Methods

Sampling was conducted during periods of high (June, 2011) and low (September,2011) water level at five sampling sites (Table 1, Figure 1), according to AQEM protocol (AQEM 2001). The semi-quantitative sampling was performed using a hand net (25x25 cm, 500 μm mesh size). The multi-habitat sampling procedure (Hering et al., 2004) was applied. Samples were preserved using 70% ethanol solution and further analysed in the laboratory.

 

tab1
Table 1: Sampling sites

 

1
Figure 1: Map of sampling sites

Mean annual water temperatures at sampling sites (according to the Annual Water Quality Report, 2011) are shown in Figure 2.

The following metrics were selected to be used for indicative assessment of ecological status: Zelinka and Marvan Saprobic Index (Zelinka & Marvan, 1961), BMWP (Biological Monitoring Working Party) Score, ASPT (Average Score Per Taxon), number of Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa (Armitage et al., 1983), total number of taxa and Shannon-Weaver's Diversity Index (Shannon, 1948). Saprobiological analyses were carried out by using a list of bioindicator organisms according to Moog (Moog, 1995). Some taxa were not identified to the species level due to low level of confidence and the complex identification process. The metrics calculation was done using AQEM software (AQEM, 2002). Indicative status assessment was performed according to the national legislation (Official Gazette of the R. of Serbia 74/2011), based on ecological status classes for rivers Type 2 (large rivers with medium grain-size mineral substrates, except Pannonian plain rivers), as shown in Table 2. Methodology of investigation was designed according to recommendations provided by the EU Water Framework Directive (WFD, 2000).

 

2
Figure 2: Mean annual water temperatures (°C) at sampling sites during 2011

 

tab2
Table 2: Ecological status class boundaries of used indices