Presentation of two rivers:

1. Those rivers are located in the North-West of Greece Presentation of two rivers: Voidomatis and Aoos

3. Its spring is near Vicos village It ends in Aoos river Its length is on average 31 km Voidomatisriver:

4. Its spring is located in valakalita (Mavrovouni mountain) The main flow’s length is about 75 km (without taking in account the two tributaries at the spring ) This river continues in Albania Aoos river:

5. Calcarous rock Sediment (“alluvions”) Geology Voidomatisriver: Two main kinds of geological formations Altitude The river’s spring is at a high of 950m and joins Aoos river at 600m (0 m is the ocean level)

6. Aoos river: Three main kinds of geological formations • Ultrabasic and basic ophiolitic rocks (diabasic composition) • Flysch (includes sand and limestone) • Virgla formation (limestone) Altitude The river’s spring is at 800m high and at the Greek border, the altitude is 500m

7. Sampling sites Voidomatis river: The samples have been made just before the river reach Aoos river, at an altitude of on average 600m Samples

8. Aoos river: Here samples have been made near Konitsa at an altitude of 500m Samples

9. Vegetation - The plants samples in the two areas are characteristic of the Riparian vegetation - The most important factor for the vegetation is the river and not the altitude, so that no furs or pines could be found. • We generally found the same plant species in the two rivers – except: • In Voidomatis river: Equisetum arvense, Juncus effusus and Corylus avellana • In Aoos river: We have found an algae: Cladophora -Cladophora prefers sheltered areas (without a big current), and is an algae growing in nutrient-rich waters (personal communication). Therefore the presence of this algae indicates that Aoos river is slower flowing with greater nutrient enrichment than Voidomatis where Cladophora was absent. - This must not only be related to the river quality since we have made our samples on 50 m on average, and we could have missed other species that were farther.

10. Profile of the Viodomatis river 3 2 2 1 1 – In the water 2 – On the edge 3 – On the bankment

11. 3 2 1 Profile of the Aoos river 1 – In the water 2 – On the edge 3 – On the bankment

13. Distributed throughout Platanusorientalis Platanus o. is mostly found in moist and rich-soil areas The trees’ roots may be down in the water but despite the fluctuations of water, the plant should not be affected.

14. Juncussp. Alnus sp. All Juncus species are almost always found in wet areas Alnus has a tolerance to moist soils and grows rapidly

15. Salix fragilis Salix is generally found near stretches of water, and is also a riparian plant

16. Equisetum arvense It very often forms dense colonies and grows mostly on sand or loam. We have found them near the water but it can also be present inside. It likes sunny places.

17. Calamagostis arundinacea Berula erecta This herb performs best in rich, well drained soils It is also a wet land plant that prefers sunny, marshy areas like steam sides

18. Methodology Sampling of benthic invertebrates * The 3-minute kick-sweep method was used in both rivers * In Voidomatis three samples were taken • One from the edge to edge • One from the edge to the middle • One around the shore * In Aoos river were two samples taken - Both from the edge to the middle * Samples collected were stored in bottles and preserved using formalin

19. Sorting out the benthic invertebrates * In the laboratory each sample was sorted separately * A sieve was used to wash the sample * The invertebrates were collected in Petri dishes

20. Identifying the benthic invertebrates * A stereoscope was used • Keys were used to determine them to the level of family • This because the index calculated (BMWP, Lincoln and • the Greek value system) works with families.

21. Physical parameters Substrate

22. Comparison of the physical parameters in the two rivers

23. 0 m 3 m 6 m 9 m 12 m 13,5 m 0 m/s 0,33 m 0,44 m 0,61 m 0,41 m/s 0,77 m/s 0,93 m 0,44 m/s 1,5 m 2,49 m/s 0,44 m/s Physical structure Voidomatis river Discharge (Area*current)  13,95 m3/s

24. Discharge (Area*current) Physical structure of the Aoos river  10,63 m3/s

25. Biological monitoring The use of changes in community structure to monitor pollution commonly involve invertebrates and this group is considered the most appropriate biotic indicators of water quality in E.U. countries (Metcalfe 1989), including Greece (Anagnostopoulou et al,1994). The biotic indices are based on the tolerance of benthic macroinvertebrates or other organisms to low oxygen conditions.

26. Results of the Voidomatis river PERCENTANGE ABUNDANCE OF BENTHIC INVERTEBRATES.

27. RESULTS OF VOIDOMATIS RIVER

28. Piecharts showing the percentage abundance of benthic invertebrates for 3 samples in the river Voidomatis.

29. Piechart of total percentage of zoobenthos’ presence in the samples

30. Results of Aoos river PERCENTANGE ABUNDANCE OF BENTHIC INVERTEBRATES.

31. RESULTS FROM AOOS RIVER

32. AOOS RIVER: PIECHARTS OF THE ORDERS OF THE BENTHIC INVERTEBRATES

33. Conclusion Biotic Indices According to both the Greek and English Biotic Indices used the water quality of the Voidomatis river is excellent , whereas the Aoos river water quality scores excellent with the English Index and good with the Greek. The difference in performance of both indices for the Aoos river may be explained by the fact that the English Biotic Index is a qualitative test only and ignores the relative abundance of different groups in the sample. The Greek Index however is both qualitative and accounts for relative abundance and therefore gives a more accurate representation of the water quality based on the invertebrate community structure. In the Voidomatis river sample, the absence of a difference between the Indices may be related to the very high scores obtained.

34. Both rivers are located in the National Park of Vikos – Aoos. Voidomatis is in the core of the N.P. where all the human activities are forbidden, whereas Aoos is in the peripheral zone where some activities such as agriculture are allowed. Because of this one can observe a slightly better water quality in Voidomatis river.

35. Benthic Invertebrates The high water quality is reflected in the benthic invertebrates present. In both rivers the greatest percentage of invertebrate families are high scoring in the biotic indices. The lower scoring families contribute only a small percentage of the total families sampled. The differences in the orders found, e.g. the inverse abundance of Ephemeroptera and Trichoptera between both rivers, is probably related more to sampling error i.e. small sampling sizes, only one station etc. and so chance sampling of concentrated populations of these orders, than to water quality. However the higher percentage of Trichoptera found in Voidomatis river may be due to the fact that the case bearing families are generally intolerant to moderate enrichment. Also Trichoptera prefer stronger current environment..

36. In Voidomatis Diptera represent 11.5% of the total sample and in Aoos 1% however no Chironomidae larvae were present. These larvae are usually the most abundant Diptera in aquatic ecosystems, occuring in a wide range of ecological conditions. The association between filamentous algae and the Chironomidae larvae is often stated in the literature therefore the very low level of these algae in both rivers may explain the absence of Chironomidae.

37. Physical Parameters The physical parameters measured during this study are generally of the same range of those recorded in other studies e.g. Bobori et al 1999. This study of the Aliakmon river showed generally the same physical parameter levels and the water quality of this river was scored as excellent/good using biotic indices (M. Lazaridou – Dimitriadou et al 2000). Between the two rivers in this study a negligible difference is observed for pH, DO2 content and percentage, and substrate (small percentage of boulders and silt were present only in Aoos river). The temperature,conductivity and TDS differences observed in both rivers are very difficult to explain but may be attributed to the higher discharge recorded in Voidomatis river. Larger discharge may be due to the inclination of this river from source (900m altitude ) to sample site which was greater than in Aoos river and also there was a greater depth (at the sample site) in Voidomatis river.

38. Sampling problems • Sampling was carried out at only one station with no spatial or temporal repetition.One random sample may by chance target a large population of one species and so distort the results. • Sampling should be carried out by just one individual otherwise, with the three minute kick method, different kicking technique and strength may (the effort) effect the size and quality of the sample taken. • The number and position of the samples taken was not consistent for both rivers and so is not comparable. For example the time may not have been 3 minutes in Aoos river because it was very difficult to walk in the river and a lot of time were lost. Also sampling time for Voidomatis river was 9 minutes, whereas Aoos river was sampled only for 6 minutes. • No attempt was made to measure chemical parameters ( nutrients, nitrogen, phosphorus etc). The application of biotic indices provides a more integrated result concerning water pollution when combined with measurements of physical and chemical parameters.

39. Lack of specialist knowledge about the ecology and biology of macroinvertebrates with in the study group

40. References • http://www.ellada.com • Photos of rivers: Kapfer Geraldine • http://www.wisc.edu/botit/img/bot/401/ • Drawing : Schneider Christine • http://www.terra.ecol.ktle.hu/haznod/htm/Calamagrostis arundinacea.htm • http://www.euronet.nl/users/mbleeker/folis/bsmain-e.html • D.C. Bobori & S.D. Mourelatos – Physical parameters and nutrient content of the surface waters of the river Aliakmon (Greece) – Editors Freising-Weihenstephan/FRG, 1999 • M. Anagnostopoulou – The relationship between the macroinvertebrate community and water quality, and the applicability of biotic indices in the river Almopeos system (Greece), University of Manchester, 1992 • R. Wellinghorst – Wirbellose Tiere des Susswasser, Friedrich Verlag, Seetze, 1993

41. http://www.apr.ethz.ch/CD-ROM/Familien/Equicetaceae/Equisetumhttp://www.apr.ethz.ch/CD-ROM/Familien/Equicetaceae/Equisetum • http://www.terra.hu/haznod/jpg/Calamagrostis.arundinacea.1.html • http://www.puc.edu/Faculty/Gilbert_Muth/Berula#erecta

42. This presentation on Voidomatis and Aoos rivers has been made with the cooperation of all the following European students: Stevenson Joan Bousiaki Elena Patoux Clothilde Sarris Marcos Schneider Christine Nordstrom Kerstin Nehrwein Birgit Svensson Jessica Kapfer Geraldine Ringsbo Jens von Schantz Mattias Francis Nikki