1. http://themedpartnership.org Neretva Delta River wetland (Croatia) Dr. Sc. Ognjen BONACCI prof. emeritus Faculty of Civil Engineering, Architecture and Geodesy, Split University, Croatia E-mail: obonacci@gradst.hr

2. Ramsar site Neretva River Delta

3. Map of the NRDW and the Hutovo Blato wetland Ramsar sites

4. 1. Name of wetland: Neretva delta Wetland general type: Wetland complex (A, H, J, ) 2. Municipality, Country: Dubrovnik-Neretva County, Croatia Coordinates: 43° 01' 40" N; 17° 34' 25" E 3. Wetland surface (km 2 ): 127.42 Elevation (m): 0.5 Average depth/length/width (m): 0.5/20000/3000 4. Contributing surface area (km 2 ): 3000 (?) 5. Contributing aquifer area (km 2 ): 500 (?)Aquifer type: Water Table 6. Mean rainfall (mm/y): 1250Mean T (ºC): 15.7Mean ET (mm/y): 880 7. Underlying lithology : Carbonate rocks and carbonated sediments 8. Wetland genesis: Delta/estuary and floodplain 9. Wetland sediments: Sandy and organic-rich 10. Water source: Rainfall on the wetland, fluvial inundation and shallow groundwater 11. Groundwater flow type: Flow through and discharge area, closed, non saline Groundwater dependence: Shared 12. Hydroperiod: Seasonal and variable 13. Hydrochemistry: Electrical conductivity (mS/cm) (100-300); Dominant (>50 %) anion or two anions (Cl, SO4); Dominant (>50 %) cation or two cations (Na, Ca) 14. Dominant vegetation: Halophytic vegetation 15. Trophic state: Eutrophic vegetation 16. Functionality: Partly moderately altered (30%) and partly highly altered (70%) 17. State of knowledge: Water quality monitoring, biological information 18. Management status: Ramsar site; Management Authority Wetland general characteristics

5. Geography The Neretva River forms a worldwide unique karst delta, where the tributaries entre the logons and lakes through underground aquifers. The Neretva River Delta is situated in southern Croatian part of the Adriatic Sea coast. On 18 January 1993 the Neretva Delta River Wetland (NRDW) was designated as a Ramsar site. Its area is 12,742 ha. Altitudes of the NRDW range between ±0 m above sea level (m a.s.l.) and 135 m a.s.l. Out of 12,742 ha of the NRDW Ramsar site in Croatia, five localities covering 1,724 ha are protected according to the Law on Nature Protection. Besides these, there are more than 3,000 ha of wetland habitats that are still not legally protected.

6. Mouth

7. Mouth of the Neretva River

8. Location Vidrice

9. Right bank

10. Wetland services status and trends (1/2)

11. Wetland services status and trends (2/2)

12. Climate The climate on the area is typically Mediterranean with mild, rainy winters and warm and relatively dry summers. The average annual air temperature is 15.7°C, with a minimum daily average temperature in December-February of about 7°C. The temperatures rarely decrease below 0°C. A maximum temperature occurs in July and August when maximum temperatures can surpass 40°C. It should be stressed that increasing trend as well as statistically significant jump of mean annual air temperatures occurred in 1990. The average annual rainfall is 1,250 mm. December is the rainiest month while July is the driest one. The average annual evapotranspiration is 880 mm. In the analysed area there are more than 2,400 sunny hours per year.

13. Landscape Due to very specific way of life of local people who have co ‐ existed with the wetland through centuries, the Neretva River Delta represents the unique landscape in Europe. It is characterized by diversity of wetland habitats mixed with agricultural land surrounded by karst hills as well as with the sea at the river mouth. Agricultural land was traditionally created through the process of digging canals and making small land plots with excavated wet soil on its top. Farmers are moving between the parcels and through the marsh in traditional small boats (local names “trupa” and “lađa”). Besides such traditional agriculture landscape, there are large complexes of intensively managed agricultural land with plantations of tangerines and greenhouses with vegetables created after extensive land ‐ reclamation works in 1960’s.

14. Trupa and marathon (in August) Start in Metković

15. Tangerine and water melon

16. Neretva River The Neretva River flows through Bosnia and Herzegovina and Croatia. Its total length is 230 km, of which 208 km are in Bosnia and Herzegovina, while the final 22 km are in Croatia. The size of the Neretva watershed is estimated on 10,380 km 2 in total; in Bosnia and Herzegovina 10,110 km 2 with the addition of the Trebišnjica River watershed and in Croatia 280 km 2. Waters of the Neretva River and the Trebišnjica River catchments are interconnected through the karst terrain. Due to this fact it is difficult to divide their watersheds. The whole territory of two catchments is covered by karst, and is filled with sinkholes, underground watercourses as well as with karst poljes that are temporarily flooded.

17. Delta of the Neretva River map Q av ≈ 355 m 3 /s

18. The pronouncedly irregular natural hydrological regimen of the Neretva River has been greatly regulated after construction of the HEPP-s in the Neretva River basin. There are the following four HEPP-s on the Neretva River: (1) HEPP Jablanica; (2) HEPP Grabovica; (3) HEPP Salakovac; and (4) HEPP Mostar. Construction and operation of the HEPP-s started in 1977. Sedimentation of suspended and bed load sediments in their reservoirs causes erosion in downstream sections of the Neretva River. HEPP-s on the Neretva River

19. The main ecological threats The main threats to ecological character of the NRDW are: (1) expansion and intensification of agriculture; (2) excessive use of pesticides and fertilizers; (3) fragmentation of wetland habitats; (4) spreading of urban zones on account of wetland; (5) water pollution with non ‐ purified urban and industrial waters; unsolved land property rights; (6) illegal taking of state owned agricultural land, including marshes; (7) non ‐ regulated recreational and touristic activities, especially on the river mouth; (8) illegal hunting and fishing; (9) frequent fires in reed beds; (10) land reclametion; (11) eutrophication etc.

20. Species According to the International Union for Conservation of Nature Red List of Threatened Species, the Neretva River Delta with surrounding area supports significant number of globally threatened species in categories CR, EN, VU and NT. They include: 1 VU and 2 NT mammals; 5 NT birds; 2 NT reptiles; 1 VU amphibian; 2 CR, 1 EN and 5 VU fishes; 1 VU mollusc. The Neretva River Delta is also important site for a number of species of European concern that are protected by the Birds Directive and the Habitats Directive as well as by the Convention on the conservation of European wildlife and natural habitats. European Red List species include: 3 NT vascular plants; 1 VU and 4 NT mammals; 2 NT reptiles; 1 VU amphibian; 2 CR, 1 EN and 5 VU fishes; 1 VU dragonfly and 1 VU mollusc. Regarding regularly occurring ornithofauna, the Neretva River Delta supports 80 birds under BirdLife categories of Species of European Concern (SPEC 2 and SPEC 3 – 8 vulnerable, 34 declining, 5 rare, 32 depleted and 1 localized) and 46 birds protected species of the Birds Directive. The Neretva River Delta is important for 60 Croatian Red List species (8 CR, 19 EN, 10 VU and 23 NT). The Neretva River Delta is proposed NATURA 2000 site (SPA and pSCI).

21. Fish species The whole Neretva River Delta represents the habitat used by around 150 fish species, including marine and freshwater species as well as species of brackish waters. Out of 49 freshwater fishes there are even 19 species endemic to the Adriatic Sea basin, 4 of which are Croatian endemics. One subspecies and five species inhabit only the Neretva River and its tributaries. The Neretva River Delta and its tributaries are exceptionally rich in fish species. Out of almost 150 species that use watercourses and/or estuary in some stage of their life, 49 are freshwater fishes and out of them even 19 are endemic for Eastern Adriatic catchment area while 4 are endemic for Croatia. Due to its high biological production, the Neretva River mouth is a feeding ground for many kinds of fish. The delta, lagoons and bodies of brackish water present spawning sites and nurseries for fish and crayfish which spend the rest of their lives in fresh or salt water. These water bodies are important for many species concerning their migrations. The most famous and characteristic for this area is the European eel (Anguilla anguilla). Adult eels migrate in the autumn towards the sea while during the springtime juvenile ‘glass eels’ enter the delta to live there until their adulthood.

22. Fish an bird Spanish sparrow is regular breeder at Neretva River delta trout

23. Cultural and historical heritage The Neretva River Delta is extremely rich with cultural and historical heritage. This area was inhabited by Illyrian tribes even since the Iron Age. It is full of archaeological remnants from pre ‐ historical times as well as from times of ancient Greece and Rome.

24. Museum in Narona Narona was the name of the ancient Roman city.

25. Main direct drivers of change (1/2)

26. Main direct drivers of change (2/2)

27. General state of conservation is good with positive trend. The main contribution of groundwater to the wetland services is in fact that groundwater is fresh and clean due to fact that it comes from karst area which is not densely populated. The forecasted evolution of the wetland-groundwater relationship, in view of the main drivers of change acting in the area can be negative due to sea water intrusion, increasing of air temperature, urbanization etc. Main conclusions

28. Conclusions Water resources management in any coastal wetlands requires the degree of interdependence between groundwater and terrestrial ecosystems to be known. This is especially important in case of the NRDW. The relationship between surface water and groundwater needs to be better understood. One consequence of the coastal location of this wetland is the strong marine influence on water chemistry, which makes it significantly more difficult to analyse the possible relationships with groundwater, as the salinity of water in the wetland is elevated due to high evaporation.

29. Thank you for your kind attention! Augusteuma in Narona Archaeological museum - Narona