Biologia 66/3: 411—417, 2011 Section Botany DOI: 10.2478/s11756-011-0032-3 Demonstration of the Bzura River restoration using diatom indices Barbara Rakowska & Ewelina Szczepocka Algology Laboratory, Department of Algology and Mycology, University ofLód´ z, 12/16 Banacha Str. PL-20-237 Lód´ z, Poland; e-mail: [email protected] Abstract: The quality of running waters is reflected in the composition of benthic diatom assemblages. The biological assessment of changes in the composition, and thus of changes in water quality, was carried out in the lowland mid-sized Bzura River, Central Poland, over the period of 30 years. The benthic diatom material consisted of samples collected in two investigation periods, in 1972 and in 2003–2004. The methods applied were three diatom indices, IPS – Specific Pollution Sensitivity Index, GDI – Genetic Diatom Index and TDI –Trophic Diatom Index, and the OMNIDIA computer program, which are commonly used in Europe. The aim of the study was demonstrating the process of restoration that occurred in the river. The Bzura was included to the most polluted ones in Poland till 1996. Since 1998 a gradual improvement in water quality has been observed, which is caused by a number of biological-technical measures, mostly a proper organization of sewage management in most cites located on the river. In 1972 the IPS classified Bzura water into Water Quality Class IV-V, while in 2003–2004 it reached much higher values, i.e. Class III-IV. On the basis of the GDI Class III was determined in the whole river in 2003–2004, while its values indicated Class III-IV in 1972. The trophic index, TDI attributed Bzura water to the eutrophic to hypereutrophic zone in 2003–2004, and to one degree better water, i.e. from the mesoeutrophic to eutrophic zone, in 1972. From the carried out research it follows that the IPS is the best index, which may be commonly applied to assess saprobic pollution of running waters in Poland. It indicated an improvement in water that occurred in the Bzura over 30 years and took into account the impact of pollution sources and tributaries in given river sections. Key words: Bacillariophyceae; biological assessment of water quality; indicator species Introduction and phytobentos, benthic invertebrate fauna, and fish fauna, play the main indicator role in biological water To comply with WFD (Framework Water Directive assessment. Analyses of phytobenthos have been lim- 2000/60/EC) requirements assessment of water quality ited to diatoms only. On the basis of diatom indicator should be carried out using indicator organisms, which values diatom indices used in the biological assessment supply precise information on conditions occurring in of running water quality have been developed; these the environment. Till recently the assessment of water indices are such as DES – Descy’s (1979) Index, EPI- quality was carried out mainly on the basis of physico- D – Eutrophication/Pollution Index based on Diatoms chemical analysis, which determined water quality on (Dell‘Uomo 1996), IBD – Indice Biologique Diatomeé the very moment of the measurement. This measure- (Lenoir & Coste 1996), IDAP – Indice Diatomique ment was incomplete and much biased, because wa- Artois-Picardie (Prygiel et al. 1996), GDI – Generic Di- ter quality experiences short-term quality fluctuations, atom Index (Coste & Ayphassorho 1991), IPS – Specific for example when pollutants are being released to it. Pollution Sensitivity Index (CEMAGREF 1982), LMI – In contrast, water organism inhabiting an investigated Leclercq & Maquet’s (1987) Index, SLA – Sládečka’s ecosystem are continuously affected by specific physico- Index (1986), TDI – Trophic Diatom Index (Kelly & chemical conditions ensuing from the type and degree Whitton 1995). of pollutants, hence their composition enables the re- Numerous investigations of diatom indices carried searcher a more objective determination of water qual- on in the world aim at selecting the index group that ity. precisely and objectively assess water quality. The in- Since the 1st May 2004 Poland has been a full dices of this group would be widely used in applied sci- right member of the European Union and, consequently, ences and serve scientific and management centers to has been obliged to implement Framework Water Di- assess the biological quality of water. rective 2000/60/EC (WFD). The WFD was voted by Large-scale investigations using diatom indices, in- the European Parliament and the Council of the Eu- cluding monitoring studies, are carried on in France ropean Union in 2000; it deals with ecology and water (Prygiel & Coste 1999; Prygiel 2002), Great Britain protection problems. According to WFD assumptions, (Kelly et al. 1995; Kelly 1998; Kelly 2003; Kelly et al. four groups of organisms, phytoplankton, macrophytes 2008) and Finland (Eloranta & Soininen 2002). Diatom c 2011 Institute of Botany, Slovak Academy of Sciences 412 B. Rakowska &E.Szczepocka indices were also successfully applied outside Europe, in sis of three diatom indices: IPS, GDI, TDI. The assess- Africa for example (Harding et al. 2005; Rey et al. 2004; ment was carried out for two sampling periods, in 1972 Taylor et al. 2007). (Rakowska 1977), when the rivers was most polluted, In Poland, investigations on diatom indices were and in 2003–2004 (Szczepocka 2008), when an improve- carried out by Kwadrans et al. (1999), Bogaczewicz- ment in water quality was observed in physico-chemical Adamczak & Ko´zlarska (1999), Rakowska (2001), analyses. This assessment enabled demonstrating the Bogaczewicz-Adamczak et al. (2001), Bogaczewicz- process of the Bzura River restoration, which began Adamczak & Dziengo (2003), Zgrundo & Bogaczewicz- with proper organizing of sewage management along Adamczak (2004), Zelazowski˙ et al. (2004). Till today, the river course. respective investigations concerned mostly the applica- tion of three indices, IPS – Specific Pollution Sensitiv- Study area ity Index (CEMAGREF 1982), GDI – Generic Diatom Index (Coste & Ayphassorho 1991), TDI – Trophic Di- The Bzura is a left tributary of the Vistula River, emptying atom Index (Kelly & Whitton 1995) for the assessment to the latter at 587.3 km from the sources; its mean dis- of water quality in the rivers of southern Poland (Odra, charge at the outlet is 28.6 m3/s. If flows across two large Wisla, Raba) and in northern Poland (water of the Bay administrative regions of Central Poland, theLód´ zandthe Mazovian Voivodeships. The length of the river is 166.2 km, of Gda´nsk). 2 In the present paper these three indices were ap- and the area of its catchment 7,787.5 km . In the 60s and 70s of the 20th c. the Bzura River per- plied for the assessment of water quality in central formed the function of a typical sewage canal, to which huge Poland using the Bzura, one of the largest rivers of the amounts of industrial and communal waste-water were re- Lód´ z Region, as an example. leased. All this caused the Bzura River to be included to the The aim of the present study was the biological as- most polluted rivers in Poland till 1966. In the 90s of the sessment of water quality in the Bzura River on the ba- 20th c., owing to the liquidation of much industry, mainly Table 1. Chemical water parameters of the Bzura River in 1972 and in 2004. Site Dissolved oxygen BOD5 Ammonia nitrogen Phosphates mg O2/L mg O2/L mg N/L mg PO4/L 1972 2004 1972 2004 1972 2004 1972 2004 1nodate 2 average 7.7 average 10.15 min 2.8 min 1.9 min 0.19 min no detected min 0.18 min 0.12 max 14.0 max 4.4 max 10.3 max 0.45 max 0.94 max 0.43 average 8.4 average 2.6 average 10.49 average 0.2 average 0.56 average 0.24 3 not detected average 8.167 min 100.0 min 3.0 min 1.0 min 0.17 min 0.66 min 0.13 max 520.0 max 8.4 max 33.0 max 0.6 max 6.0 max 1.62 average 310.0 average 5.03 average 17.0 average 0.36 average 3.33 average 0.57 4 not detected average 10.09 min 40.0 min 3.0 min 1.0 min 0.71 min 0.42 min 0.15 max 280.0 max 6.7 max 48.5 max 1.85 max 12.5 max 0.57 average 160.0 average 5.0 average 24.75 average 1.17 average 6.46 average 0.35 5 not detected no data min 70.0 min 0.5 min 5.0 min 0.01 min 0.32 min 0.01 max 300.0 max 24.0 max 23.4 max 1.51 max 5.5 max 0.68 average 185.0 average 4.05 average 14.2 average 0.62 average 2.91 average 0.28 6 not detected no data min 30.0 min 1.0 min 1.0 min 0.02 min 0.56 min no detected max 300.0 max 11.6 max 19.0 max 5.48 max 23.0 max 4.26 average 165.0 average 3.14 average 10.0 average 1.32 average 11.78 average 0.6 7 average 4.5 average 9.0 min 16.0 min 2.0 min 1.0 min 0.15 min 0.19 min 0.1 max 96.0 max 5.6 max 12.9 max 0.73 max 1.0 max 0.58 average 56.0 average 2.7 average 6.95 average 0.39 average 0.6 average 0.36 8 average 4.4 average 9.14 min 6.4 min 2.0 min 0.3 min 0.22 no data min 0.19 max 48.6 max 6.5 max 2.2 max 0.74 max 0.92 average 27.5 average 2.8 average 1.25 average 0.46 average 0.61 9 average 3.4 average 9.57 min 6.8 min 2.0 min 0.26 min 0.25 no data min 0.21 max 24.5 max 8.7 max 3.25 max 1.32 max 0.89 average 15.65 average 3.3 average 1.76 average 0.51 average 0.57 Demonstration of the Bzura River restoration using diatom indices 413 Table 2.