In the present paper, the results of two macrozoobenthos analysis based indices (Saprobic Index and Extended Biotic Index) are used as biological indicators in the assessment of river water quality. The objective of the paper is to establish the extent to which the results of these methods are comparable. The results indicate that both indices are suitable for assessing the quality of river water in the Croatian hydrographic network. Major deviations were only detected in xenosaprobic waters, i.e. at the springs of the Krka River and Crna rijeka, where the values of the Extended Biotic Index indicated poorer water quality

Mladen Kerovec

Zlatko Mihaljević

Croatian Journal of Fisheries

Directory of Open Access Journals

ISSN 1330–061X UDK: 006.73:504.05](282)CODEN RIBAEG Original scientific paperCOMPARISON OF TWO BIOLOGICAL METHODSFOR ASSESSMENT OF RIVER WATER QUALITYBASED ON MACROZOOBENTHOSM. Kerovec, Z. Mihaljevi}SummaryIn the present paper, the results of two macrozoobenthos analysis based indices(Saprobic Index and Extended Biotic Index) are used as biological indicators inthe assessment of river water quality. The objective of the paper is to establishthe extent to which the results of these methods are comparable. The resultsindicate that both indices are suitable for assessing the quality of river water inthe Croatian hydrographic network. Major deviations were only detected inxenosaprobic waters, i.e. at the springs of the Krka River and Crna rijeka,where the values of the Extended Biotic Index indicated poorer water quality.Key words: macrozoobenthos, Saprobic Index, Extended Biotic Index, CroatiaINTRODUCTIONIn addition to being an important food source for fish, benthic invertebrateshave become an important factor in assessing water quality.As a candidate state, Croatia is currently aligning its legislation with that ofthe European Union. In the water sector, the most important piece of legisla-tion is the Water Framework Directive (WFD EU) (Directive 2000/60/ES). Theclassification of the ecological state of river and lakes is conducted using biologi-cal, hydromorphological, chemical and physicochemical elements. According tothe WFD, biological quality elements to be monitored are: macrozoobenthos,fish, phytobenthos and saprophytes. The Water Framework Directive does notexplicitly request that the Saprobic Index be used for the determination of riverwater quality, but does require the use of benthic invertebrates.Water Classification Act (Uredba o klasifikaciji voda) (Narodne novine,77/98) lists two biological indicators in the assessment of water quality: the11Ribarstvo, 68, 2010, (1), 11—18M. Kerovec, Z. Mihaljevi}: Assessment of river water qualityProf. dr. sc. Mladen Kerovec, doc. dr. sc. Zlatko Mihaljevi}, Department of Zoology, Di-vision of Biology, Faculty of Science, University of Zagreb, 10000 Zagreb, Rooseveltovtrg 6, HR, e–mail: mkerovec@biol.pmf.hrSaprobity Index (P a n t l e and B u c k , 1955) and the Biotic Index (W o o d i -w i s s , 1964). However, in the Regulation on amendments to the Water Classi-fication Act (Uredba o izmjenama i dopunama Uredbe o klasifikaciji voda,Narodne novine, 37/08), the biotic index was eliminated as one of the biologi-cal indicators of water quality.The results shown in this paper allow for certain conclusions to be drawnon the efficacy and possibilities of using macrozoobenthos in determining wa-ter quality, using two methods: the Saprobc Index (SI) and the Extended Bi-otic Index (EBI) (G h e t t i , 1986). The objective of this paper was to establishthe extent to which results obtained in these two indices on the rivers of theCroatian hydrographic network can be compared. The use of SI, currently theonly legitimate biological method in Croatia, can have certain limitations inroutine water quality assessments. Namely, it implies the determination of in-dicators to the species level, which requires highly specialised determinationexperts. This slows the analysis and makes it more costly.STUDY SITESFor the purpose of comparative study and assessment of the level of applica-bility of SI and EBI, macrozoobenthos were collected at seven sampling sitesin the Croatian hydrographic network during 2003 and 2004. Sampling on theSava River was conducted at two stations: Otok (upstream from Zagreb) andOborovo (downstream from Zagreb) in all four seasons: summer (July), au-tumn (December), winter (February) and spring (May). Macrozoobenthos ofthe Kraljevec Stream was also sampled at two sites. The first (Kraljevec 1)was downstream of the Queen’s Well on Mt. Medvednica, while the second(Kraljevec 2) is in the Mihaljevac area (Zagreb) where the creek enters thecovered area. The last three study sites were on the Korana River near Veljunand at the spring of the Krka River near Knin (at Topoljski buk) and theCrna rijeka near the Plitvice Lakes. Samples at the sites on the KraljevecStream and the Krka River were collected in summer (July), autumn (Novem-ber/December) and winter (February). At the spring of the Crna rijeka(Plitvice Lakes) and the Korana River near Veljun, samples were collected insummer (July), autumn (December) and spring (May).MATERIALS AND METHODSAt all study sites, qualitative samples of macrozoobenthos was collected indepths down to 1m using a hand net (mesh size 0.5 mm) from all availablemicrohabitats. Collected samples were placed in wide–neck bottles and con-served in 70% ethanol. In the laboratory, organisms were removed from thesubstratum, counted, and identified to the lowest possible taxonomic category.12Ribarstvo, 68, 2010, (1), 11—18M. Kerovec, Z. Mihaljevi}: Assessment of river water qualityDESCRIPTION OF BIOLOGICAL METHODSSaprobic index (SI)The value of the SI is calculated according to the following formula (P a n t l eand B u c k , 1955):S s x hSI = —————S hs = saprobic value;h = relative abundance (h = 1, 3 or 5 if organisms of the taxonare found incidentally, frequently or abundantly, respectively),According to B a u r (1987), instead of an assessment of relative abun-dance, the actual abundance of taxa was used. The obtained SI values werecorrected based on the established number of indicator taxa, as follows:The saprobic values (s) for individual indicator taxa were obtained fromthe literature (W e g l , 1983; M o o g , 1995).Extended Biotic Index (EBI)For assessments of water quality, qualitative samples of macrozoobenthos werecollected using a benthos net, from as many different microhabitats as possible,in order to obtain the best possible overview of the structure of the community.Some groups were determined to the genus level (Plecoptera, Ephemeroptera,Mollusca...), some to the family level (Trichoptera, Oligochaeta, Crustacea...),while for others it was sufficient to note presence at the group level (Nematoda,Porifera...). Determination need not be carried out to the species level, but onlyto higher systematic levels. The value of the EBI is determined based on thepresence of representatives of invertebrate groups of varying sensitivity to pollu-tion, and based on the number of taxa (Gh e t t i , 1986). It should also be notedthat due to this simplification in determination, the basic shortcoming of themethod is a slightly lower sensitivity than when using SI.13Ribarstvo, 68, 2010, (1), 11—18M. Kerovec, Z. Mihaljevi}: Assessment of river water qualityNumber of indicator taxa Saprobic Index1–2 S + 0.33–5 S + 0.26–12 S13–15 S — 0.216 or more S — 0.3RESULTSThe results of water quality analyses using benthic macroinvertebrates areshown in Fig. 1, where the values of the SI and EBI are given. Based onthese, individual results are shown as quality class pursuant to the WaterClassification Act (Narodne novine, 77/98) and the Regulation on amendmentsto the Water Classification Act (Narodne novine, 137/08). According to this leg-islation, water is classified into five classes based on the value of the SaprobicIndex ranging from 1 to 4, and values of the Biotic Index from 1 to 10. Con-sidering that the EBI is used in this study, whereby the values can be (andare) over 10, we proposed that EBI values for quality class I be from 10 to 12,and with higher values indicating fully clean water, which should be conside-red as xenosaprobic quality class. The situation with the SI is similar, as ac-cording to the Water Classification Act, the lowest value is 1, while the prese-nt study indicates that values can be lower, which would also be values char-acteristic of exceptionally clean or xenosaprobic waters.Kraljevec StreamAt the site Kraljevec 1, the highest SI values were found in July and lowest inFebruary, when one of the values was within the bounds of xenosaprobic(0.99). All other values are characteristic for quality class I, and the highestmeasured value was in July (1.39). The EBI values were high in July andFebruary, indicating higher water quality than shown by the SI values.Greater fluctuations of SI and EBI values are also present by season atthe station Kraljevec 2. In July, all values were within the levels of qualityclass III, in December for quality class class II and in February, the SI valueswere within levels of quality class III (Fig. 1).Sava RiverIn the Sava River near Otok, the SI values indicated somewhat poorer waterquality in July and February than in December and May. The obtained valuesindicate the water is quality class III. There were no significant deviations ofthe SI and EBI values.In the Sava River near Oborovo, the seasonal differences in water qualityshowed greater variation that at the upstream station. The poorest water qual-ity was confirmed in July and May (quality class V). Quality was slightlybetter in December (quality class IV) and highest in February, when SI valuesindicate quality class III, while EBI values indicate quality class IV. This isalso a larger deviation of the EBI and SI values at this station.14Ribarstvo, 68, 2010, (1), 11—18M. Kerovec, Z. Mihaljevi}: Assessment of river water qualityCrna rijeka — springWater quality based on macrozoobenthos analyses at this station varied verylittle in individual seasons. All values of the SI were less than 1, i.e. in theboundaries of xenosaprobic water. However, significant deviations of valueswere obtained using the EBI method at this station, as this method indicatedquality class I in all seasons.Korana River — VeljunAll obtained values of the SI and EBI indices were within the boundariescharacteristic for quality class II. Somewhat higher SI values (i.e. slightlypoorer water quality) were recorded in July.Krka River — spring (Topoljski buk)The results indicate that at the station Topoljski buk, the SI values in all sea-sons are either at the border of xenosaprobic water and quality class I, or inthe initial values for quality class I. Significant fluctuations of water qualityindicators were established based on the EBI. During the summer period,these values indicate poorer water quality (quality class II).15Ribarstvo, 68, 2010, (1), 11—18M. Kerovec, Z. Mihaljevi}: Assessment of river water qualityFig. 1. Values of the Saprobic Index (SI) and Extended Biotic Index (EBI)on the investigated sitesSlika 1. Vrijednosti indeksa saprobnosti (SI) i pro{irenoga bioti~kog indeksa(EBI) na istra`ivanim teku}icamaDISCUSSION AND CONCLUSIONSOver the past decade, numerous water quality studies having been conductedcomparing the SI and EBI methods (B o ` a k , 2004; D r a g o j e v i } , 2006;M o l a k , 2009; P r im c –H a b d i j a , K e r o v e c et al., 2005). Based on thesestudies, the following conclusions can be drawn. First, the interpolation of re-sults obtained using these methods can present a significant problem, i.e. de-termining the boundary levels of individual water classes, and there will likelybe other issues and ambiguities concerning this. Second, the EBI has a muchcoarser spread of values, which could also be the source of the larger devia-tions from those values obtained using the SI method. And third, based on ex-periences to date, both in Croatia and abroad (Z a b r i c and [ o t P a v l o v i ~ ,1989), larger fluctuations have been recorded in both clean and heavily pol-luted waters, than is the case with only moderately polluted waters.Based on the results presented here, it can be concluded that both de-scribed methods, SI and EBI, are suitable for use in the assessment of riverwater quality. With regard to the EBI method, it can be said that it proved tobe very good in assessing water quality, especially in poorly to heavily pollutedwater. The results indicate that in such waters (Kraljevec Stream, Sava River,Korana River) there are no greater deviations from the SI values. However,when this method is applied for fully clean and clean waters (xenosaprobicand oligosaprobic), there are larger deviations from the results obtained by theSI method. The most significant deviations were obtained in xenosaprobic wa-ters, i.e. at the springs of the Krka River and Crna rijeka, where the values ofthe EBI typically indicated poorer water quality. For the Crna rijeka, the twomethods gave results that differed by a class, i.e. EBI indicated quality class Iwhile SI indicated xenosaprobic water. Even greater deviations were observedat the springs of the Krka River (Topoljski buk), where one sample differed bytwo classes. These differences are due to the relatively low diversity ofmacrozoobenthos, stemming from the relatively extreme ecological conditionsfound in these springs. Considering that one of the criteria for determiningthe EBI values and community diversity (number of taxa), it is clear that insuch habitats those values are smaller, and thus suggest poorer water quality.Namely, these are sites were groundwater, containing less oxygen and organicmaterial, springs to the surface. Furthermore, water temperature is constantand relatively low, which are also limited factors for the development ofmacrozoobenthic diversity.Based on the above, it can be concluded that both methods (SI and EBI)have certain advantages and shortcomings, but with additional explanation, in-structions and education of users, both methods could be suitable for deter-mining the quality of rivers in Croatia. The EBI method is advantageous forroutine and rapid assessments of water quality, and should be reinstated inthe Water Framework Directive.16Ribarstvo, 68, 2010, (1), 11—18M. Kerovec, Z. Mihaljevi}: Assessment of river water qualitySa`etakUSPOREDBA DVIJU BIOLO[KIH METODA ZA OCJENUKAKVO]E TEKU]IH VODA NA TEMELJU ANALIZEZAJEDNICE MAKROZOOBENTOSAM. Kerovec, Z. Mihaljevi}Na temelju analize zajednice makrozoobentosa, u radu su prikazani rezultatidvaju indeksa (indeksa saprobnosti i pro{irenoga bioti~kog indeksa) koji sekoriste kao biolo{ki pokazatelji u procjeni kakvo}e voda teku}ica. Cilj je radabio utvrditi u kojoj su mjeri me|usobno usporedivi rezultati dobiveniprimjenom dvaju navedenih indeksa. Rezultati pokazuju da su oba indeksapogodna za procjenu kakvo}e teku}ica hidrografske mre`e Hrvatske. Ve}a suodstupanja utvr|ena samo u ksenosaprobnim vodama, tj. na izvorima Krke iCrne rijeke, gdje su vrijednosti pro{irenoga bioti~kog indeksa uglavnomupu}ivale na lo{iju kakvo}u vode.Klju~ne rije~i: makrozoobentos, indeks saprobnosti, bioti~ki indeks, HrvatskaLITERATUREBaur, W. (1987): Gewasser guete bestimmen and beurtilen. Paul Parey Ver-lag, Stuttgart, 141 p.Bo`ak, K. (2004): Makrozoobentos potoka Kraljevac (Medvednica). Diplomskirad. Prirodoslovno–matemati~ki falultet, Sveu~ili{te u Zagrebu.Dragojevi}, I. (2006): Makrozoobentos potoka Bliznec. Diplomski rad. Priro-doslovno–matemati~ki falultet, Sveu~ili{te u Zagrebu.Ghetti, P. F. (1986): I macroinvertebrati nell,analisi di qualita dei corsi d,ac-qua. Manualle di applicazione Indice Biotico: E.B.I. modificato. Universi-ta di Parma, Cattedra di Idrobiologia, Trento, 111 p.Molak, Z. (2009): Makrozoobentos kao pokazatelj sezonskih i prostornih raz-lika u kakvo}i vode rje~ica Krapine i Krapinice. Magistarski rad. Priro-doslovno–matemati~ki falultet, Sveu~ili{te u Zagrebu, 1— 115.Moog, O. (1995): Fauna Aquatica Austriaca. A comprehensive species inven-tory of Austrian aquatic organisms with ecological notes. Wasser-wirtschaftskataster, Vienna, 76 p.Narodne novine (1998): Uredba o klasifikaciji voda. Br. 77 .Narodne novine (2008): Uredba o izmjenama i dopunama Uredbe o klasifika-ciji voda. Br. 137.17Ribarstvo, 68, 2010, (1), 11—18M. Kerovec, Z. Mihaljevi}: Assessment of river water qualityProf. dr. sc. Mladen Kerovec, doc. dr. sc. Zlatko Mihaljevi}, Zoologijski zavod, Biolo{kiodsjek, Prirodoslovno–matemati~ki fakultet, Sveu~ili{te u Zagrebu, 10000 Zagreb,Rooseveltov trg 6, HR, e–mail: mkerovec@biol.pmf.hrPantle, R., Buck, H. (1955): Die Biologishe Uberwaschung der Gewasserunddie Daestellung der Ergebnisse. GWF, 96, 603 pp.Primc Habdija, B., Kerovec, M. i sur. (2005): Biolo{ka valorizacija voda–Pri-mjena hrvatskog indikatorskog sustava. Prirodoslovno–matemati~ki fa-kultet, Sveu~ili{te u Zagrebu, 159 p.Wegl, R. (1983): Indeks für die Limnosaprobitat. Beitrage zur Gewasserfor-schung XIII, Band 26, 175 p.Woodiwiss, F.S. (1964): The biological system of stream classification usedby the Trent River Board. Chemistry and Industry, 443–447.Water Framework Directive (2000): Directive of European Parliament and ofthe Council 2000/06/EC — Establishing a Framework for CommunityAction in the Field of Water Policy, Brussels.Zabric, D., [ot Pavlovi~, L. (1989): Primerava dveh biolo{kih metoda (Sip-buck in E.B.I) za dolo~anje kakovosti vodotokov. Ichthyos, Ljubljana, 15,(1), 19–28.Primljeno: 12. 2. 2010.Prihva}eno: 5. 3. 2010.18Ribarstvo, 68, 2010, (1), 11—18M. Kerovec, Z. Mihaljevi}: Assessment of river water quality

COMPARISON OF TWO BIOLOGICAL METHODS FOR ASSESSMENT OF RIVER WATER QUALITY BASED ON MACROZOOBENTHOS

http://ribarstvo.agr.hr/articles/5780_COMPARISON_OF_TWO_BIOLOGICAL_METHODS_FOR_ASSESSMENT_OF_RIVER_WATER_QUALITY_BASED_ON_MACROZOOBENTHOS_en.pdf

COMPARISON OF TWO BIOLOGICAL METHODS FOR ASSESSMENT OF RIVER WATER QUALITY BASED ON MACROZOOBENTHOS

Abstract

Similar works

Full text

Available Versions

Directory of Open Access Journals