8ο Πανελλήνιο Συμποσιο Ωκεανογραφίας & Αλιείας 897

8ο Πανελλήνιο Συμποσιο Ωκεανογραφίας & Αλιείας 897 Water quality evaluation of the middle and lower reaches of Pinios river based on benthic macroinvertebrates and physicochemical parameters during the low flow and high flow season Katerina Papadaki, Yorgos Chatzinikolaou, Maria Lazaridou, Ioannou Aleksis, Vassilia Artemiadou, Aristotle University of Thessaloniki, School of Science, Department of Biology, Laboratory of Zoology, 541 24 Thessaloniki, e-mail: aik_papadaki@yahoo.com, mlazarid@bio.auth.gr Περιληψη Η παρούσα μελέτη αποσκοπεί στην εκτίμηση της ποιότητας του νερού του ποταμού Πηνειού χρησιμοποιώντας βενθικά μακροασπόνδυλα και φυσικοχημικές παραμέτρους. Δείγματα συλλέχθηκαν από 29 σταθμούς διασκορπισμένους σε 4 περιοχές της λεκάνης απορροής του ποταμού Πηνειού τον Ιούλιο 2004 (περίοδος χαμηλής ροής) και τον Απρίλιο 2005 (περίοδος υψηλής ροής). Στα δεδομένα μας εφαρμόσθηκαν οι πολυπαραγοντικές στατιστικές αναλύσεις FUZZY και CCA (CANOCO program) και ερμηνεύτηκε η ποιότητα σύμφωνα με το Ελληνικό Σύστημα Αξιολόγησης (HES και AHES-και η ερμηνεία τους).η CCA έδειξε ότι η σημαντικότερη παράμετρος που επηρέασε το βένθος την περίοδο χαμηλής ροής ήταν η θερμοκρασία του νερού ενώ την περίοδο της υψηλής ροής η συγκέντρωση του αζώτου των αμμωνιακών ιόντων. Με βάση το HES η ποιότητα του νερού διακυμάνθηκε από κακή έως καλή. Γενικά, ο ποταμός φάνηκε να επηρεάζεται σε μεγάλο βαθμό από τις ανθρώπινες δραστηριότητες και οι περιοχές εμφανίστηκαν ομογενοποιημένες ως προς την ποιότητα των υδάτων τους παρά τις μικροδιαφορές μεταξύ των επιμέρους σταθμών τους. Abstract The present study aims to estimate the water quality of Pinios river using benthic macroinvertebrate data and physicochemical variables. Biotic and abiotic samples were obtained from 29 sites in four areas in the catchment area of Pinios river during the low flow (July 2004) and high flow season (April 2005). Multivariate statistical analyses (FUZZY clustering and CCA ordination-canoco program) were applied to our data. The Hellenic Evaluation System (HES and AHES and its Interpretation Index) was also calculated. CCA indicated that the most significant variable affecting the benthic community in low flow period was the water temperature and in the high flow period the concentration of ammonium. The HES indicated poor to good water quality. In general the river was influenced by human activities and the areas seemed to be homogenous with respect to the water quality despite some differences between vicinal sites. Keywords: Pinios, benthic macroinvertebrates, water quality

898 8ο Πανελλήνιο Συμποσιο Ωκεανογραφίας & Αλιείας Introduction The European Union has obliged its member states to promote the sustainable water use, to prevent the deterioration of their water resources and to enhance the protection and improvement of the water ecosystems by bringing into force the 2000/60/EC Water Framework Directive. According to it, the use of biological parameters such as benthic macroinvertebrates in monitoring networks is considered indispensable. However, the combination of the biological approach with the physicochemical variables and their statistical analyses contribute to a more holistic approach. Materials and methods The present study took place in a part of Pinios river which is located in Central Hellas. Its length is about 205 km and the catchment basin of the river covers 10.700 km 2. Six to eight (6-8) sampling sites were selected in each of the four areas influenced by different human activities. The following land uses characterized the four sampled areas: In Area A (8 sites, 12 km length, covering from the delta up to the Tempi gorge) agricultural activities, in area B (6 sites, 8.5 km length, extending upstream of the Tempi gorge) agriculture and stock-breeding pressure, in Area C (7 sites, 12 km length, adjacent upstream to area B) municipal and industrial discharges as well as agricultural runoffs and area D (8 sites, 12 km length, downstream the city of Trikala), agricultural runoffs and municipal discharges. Sites were sampled as to benthic macroinvertebrates and physicochemical parameters during the low-flow (July 2004) and the high-flow (April 2005) season. A sample of benthic macroinvertebrates was taken at each site according to the 3-min kick-sweep method (Armitage and Hogger, 1994). The macroinvertebrates were identified down to the family level. The following physicochemical parameters were measured in situ: water temperature ( o C), conductivity (μs/cm), ph, Total Dissolved Solids (TDS, mg/l), Dissolved Oxygen (D.O. % and mg/l), nitrates (Ν-NO 3, mg/l) and ammonium (Ν-NH 4 mg/l), and in the laboratory: Total Suspended Solids (TSS, mg/l), Biochemical Oxygen Demand (BOD 5 mg/l), Ν-NO 2 (mg/l), P-PO 4 (mg/l) according to the A.P.H.A. (1985) methodology. The substrate was visually estimated according to the Wenthworth scale. The Hellenic Evaluation Score and its Interpretation Index (Artemiadou & Lazaridou, 2005) were calculated for each sample of benthic macroinvertebrates. Moreover ANOVA, FUZZY clustering (Equihua, 1990) and CCA ordination (CANOCO program) (Ter Braak, 1986) were applied to physicochemical or/and biological data as well. Results Benthic macroinvertebrates: A total of 41.300 individuals were sampled in both seasons. The benthic community consisted mostly of Ephemeroptera, Crustacea, Chironomidae (dipteran family) and Oligochaeta, while other families of Diptera, Trichoptera, Odonata, Coleoptera, Heteroptera, Gastropoda, Hirudinea and Decapoda were present in smaller numbers. Some pollution sensitive taxa were also collected from several sites in both seasons, in small numbers though. Physicochemical parameters: The water was well oxygenated in both seasons except for the Area D in July where the values of dissolved oxygen where lower than the E.C. permitted levels (Directive 98/83/EC). Furthermore, in July the Areas B and C presented high values of BOD 5. Apart from ammonium in Areas A, B and C in April, the concentrations of the other nutrients did not exceeded the E.C. limits. Biotic Indices: Poor water quality was recorded in 14 sites, moderate in 30 sites and good in 14 sites. Statistical analyses: FUZZY analysis produced 5 clusters (partition coefficient: 0.42) on the basis of benthic community. CCA analysis explained 36.4% (Diagram 1) of our data variability and the first axis was interrelated to ammonium and water temperature and the sec-

8ο Πανελλήνιο Συμποσιο Ωκεανογραφίας & Αλιείας 899 AX1 AX2 AX3 AX4 Eigenvalues: 0.245 0.119 0.11 0.083 Species-envir. Correlations: 0.947 0.878 0.880 0.862 Cumulative %variance of species data: 9.9 14.8 19.3 22.7 of species-environm: 29.4 43.7 57.1 67.0 Sum of all unconstrained eigenvalues: 2.463, Sum of all canonical eigenvalues: 0.833, Total inertia: 2.463 Diagram I. CCA diagram with physicochemical variables and 58 samples from Pinios river (July 2004 and April 2005).

900 8ο Πανελλήνιο Συμποσιο Ωκεανογραφίας & Αλιείας ond to ph and TDS. July samples were ordinated at the positive side of axis I and April ones at the negative side of the same axis. ANOVA comparisons showed that area D (downstream Trikala) was differentiated due to the highest concentrations of P-PO 4 in July. Discussion The results of physicochemical analysis indicated that the Pinios river is far from being characterized as a clean river. Significant amounts of nutrients and other pollutants end up into the river. In general, the quality of the water was worse during the high flow season (April) due to the fertilizers run off. Delta area showed the best water quality during both sampling seasons in comparison with the other areas. Many natural springs are located upstream of this area providing significant inputs of fresh water into Pinios. Areas B and C (upstream the delta area) were affected not only by intensive agricultural activities and stockbreeding but also by industrial and municipal inputs during both low and high flow period. Thus, high concentrations of nutrients were observed in April and high values of BOD 5 in July. Area D (downstream Trikala) appeared to be more influenced by municipal discharges and industrial discharges than agriculture pressures. Especially during the dry period increased concentrations of P-PO 4 were measured. Intense water abstractions for irrigation in combination with the low flow of the river, the high temperature and the municipal discharges impoverished the quality of the water. High ammonium concentrations characterized all the sites along the river in both seasons. The macroinvertebrate benthos was not very diverse due to the anthropogenic activities. Additionally, it was dominated by pollution- tolerant taxa in most sites. FUZZY analysis did not detect any faunistic differences among the four areas. The CCA ordinated the data according to the water temperature, (which was higher in July) and to the concentration of ammonium which was higher in April due to strong rainfalls and subsequent agricultural runoffs. According to the HES the water quality varied from good to bad in all four areas in both sampling seasons. The bad quality of the water is mainly attributed to agricultural run off, municipal pollutants and industrial sewage. Finally, most of the stations had a moderate water quality which in combination with the modifications of the river necessitates restoring processes to take place according to the WFD 2000/60 E.C. Conclusions Pinios river appeared to be influenced by human activities in the studied four areas in both sampling seasons according to the physicochemical parameters and the benthic fauna which was dominated by pollution-tolerant taxa. Area D (downstream Trikala) was differentiated due to the highest concentrations of P-PO 4 in July. References A.P.H.A., 1985. Standard methods for examinations of water and waste water. American Public Association inc. Washington D.C., 16th edition. ARMITAGE, P. D. and HOGGER, J., 1994. Invertebrates ecology and methods of survey, in RSPB, NRA 680 and RSNC (eds.), The New Rivers and Wildlife Handbook, Bedfordshire, pp. 151 159. ARTEMIADOU V. and LAZARIDOU M., 2005. Evaluation Score and Interpretation Index for the ecological quality of running waters in Central and Northern Hellas. Environmental Monitoring and Assessment, 110: 1-40. EUROPEAN COMMISSION, 2000. Directive 2000/60/EC of the European Parliament and the council 23rd of October establishing a framework for community action in the field of water policy. Official Journal of the European Communities L327:1-72.

8ο Πανελλήνιο Συμποσιο Ωκεανογραφίας & Αλιείας 901 EUROPEAN COMMISSION, 1998. Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption, Off. J. Europ. Commun. L330/32/5.12.98. METCALFE L.J., 1989. Biological water quality assessment of running waters based on macroinvertebrate communities: History and present status in Europe. Environmental Pollution, 60:101-139. TER BRAAK C.J.F., 1998. CANOCO- a FOR- TRAN program for canonical community ordination (version 2.1). Technical report: LWA- 88-02.