LOWER NERETVA VALLEY
Neretva River emerges beneath Zelengora mountain in eastern Bosnia and Herzegovina. Through canyons, cliffs and hollows in its upper and middle courses, it forces its way through the Dinaric Alps to spread downstream of the village of Pocitelj in Herzegovina over a vast wetland valley and to flow through its large delta into the Adriatic Sea.
Neretva is this largest river of the eastern part of the Adriatic basin. It has been harnessed and controlled to a large extent by several HE power-plants and their storage lakes, but it still remains unique in its beauty and the diversity of its landscape. At its delta, a specific way of human living has developed, which now is passing away.
After the last deglaciation, the sea level had risen and the sea had covered the karst relief as far as to the present Hutovo blato. Gravel carried by the Neretva River water had been deposited in the valley. The wetland was formed when Neretva filled up the sunk karst depressions with its rich sediments thus raising the soil. At more distant places, where sedimentation was not so high, marshes and lakes remained. In the middle of these alluvial deposits, solitary hummocks of karst scenery now dominate.
The Lower Neretva valley contains the largest and the most valuable remnants of the Mediterranean wetlands on the eastern Adriatic coast and one of the few areas of this kind remaining in Europe. Recently, such wetlands have been destroyed to such an extent that they remained mostly as scattered individual islands in an intensively cultivated and inhabited environment. Regulation of streams, construction of storage reservoirs upstream of the valley, drainage and turning the wetland into the arable land changed the appearance of this area irreversibly. The once vast reed-patches and lagoons important for wintering and migration of a wide variety of birds, as well as for fish feeding and spawning, presently are reduced to small fragments which continue to be threatened by all kinds of human activities.
Yet, this area, even in its present condition, from the biological and landscape diversity standpoint is of international importance. As such, the Lower Neretva valley has been included in the Ramsar List of the Ramsar Convention on Wetlands and in the Programme Important Bird Areas, conducted by the BirdLife International.
The valley along the last thirty kilometers of the Neretva River makes a natural entity with the river. Downstream of the mouths of its tributaries Trebižat and Bregava, the valley spreads abruptly into an alluvial fan "Neretvanske blatije" with the area of 20.000 ha. Its upper part called Hutovo blato is in Bosnia and Herzegovina and depends upon the water regime of the small Krupa River, while in its lower part situated in the Republic of Croatia the Neretva River branches creating a large delta.
As far as the nature conservation is concerned, it is obvious that this is one space which requires a joint management plan based on an integral approach and the transboundary cooperation.
Hutovo blato covers about 8.000 ha of the Neretva Valley in Bosnia and Herzegovina. Across it, the Krupa River - a tributory of the Neretva River - flows. This river together with ground waters from the adjacent karst area, is responsible for water regime and, consequently, for general conditions of life in this wetland ecological system. Relief, climate, vegetation and abundance of water create here throughout the year favourable habitat conditions for a large number of plant and animal, especially bird species. Hutovo blato is important for wintering of ducks and waders and for nesting of European threathened species such as various herons or pygmy cormorant. Owing to the vast wet surfaces of land and various marsh habitats, as well as a favourable influence of the Mediterranean climate, in winter Hutovo blato is a suitable resting place for ducks, coots and many other birds arrived here from the north of Europe.
The limestone ridge "Ostrvo" divides Hutovo blato into the upper (Deransko blato) and lower (Svitavsko blato) zones. In the upper zone there are six lakes, the largest of them being the Deransko lake. This zone is relatively well protected from the anthropogenetic impact and presents an important habitat for many plant and animal species.
In 1979, the former large marsh Svitavsko blato, after the construction of the hydro- electric power plant Capljina, became the storage lake of 1.300 ha. The lake has covered large areas with marsh vegetation, flood meadows and willow and poplar flood forests, that resulted in a considerable reduction of the number of bird and fish species. The ornithological research showed significant quantitative and qualitative changes in the bird species composition compared to the situation before 1979. Particularly important is reduction in the number of birds linked with the marsh vegetation (ducks) and flood meadows (snipes and lapwings). The international importance of this area for migratory birds has been decreased considerably.
The abundance of waters and their connection with the sea through the Neretva and Krupa Rivers, contributed to the development of very rich fish stocks in Hutovo Blato, known from ancient times as an excellent fishing place for eels and carps. Unfortunately, today fish stocks are considerably reduced. Great changes in the water regime of the Neretva River and its tributories, and in particular the disturbance of natural balance as the consequence of the construction of the hydro-electric power plant Capljina, deranged the fish movement and composition.
The main artery of Hutovo Blato is the small Krupa River, that carries waters from the Deransko and Svitavsko blato to Neretva. Having no typical source, it rushes out from the Deransko lake flowing in a snake-like stream to the Neretva River. This unusual river can flow in two directions. When water level in the Neretva River is high, the small Krupa River carries water in direction of the Deransko lake causing flooding of surrounding lands.
Since 1995, Hutovo Blato has been protected as the Nature Park managed by the Public Enterprise Hutovo blato. In a part of the Park fishing and hunting are allowed, and, besides, several foreign (alochthonous) species were imported in its ecological system, that resulted in disturbed relations inside the system. Due to the storage reservoirs in the upper Neretva River, the water regime schedule often is not in conformity with the seasonal requirements of life in this area. A coordinated planning of all further activities in the framework of a single management plan seems to be more and more pressing.
The Neretva Delta
The Neretva Delta in the Republic of Croatia covers about 12.000 ha. After extensive land-reclamation works, of the earlier twelve brances now only three have remained. The associated marshes as well as many lakes and lagoons have disappeared, too. Today, in this cultivated area the fragments only of the earlier large Mediterranean wetland are preserved. Five sites with the total area of 1.620 ha are protected in the categories of ornithological reserve (Pod Gredom, Prud and Orepak), ornithological and ichtyological reserve (the Neretva Delta) and protected landscape (Modro oko and the Desne lake). The entire delta is anticipated for protection in the nature park category by the Physical Planning Strategy of the Republic of Croatia as well as by the National Strategy and Action Plan for the Protection of Biological and Landscape Diversity («Official Gazette» no.81/99).
Here, the natural values and the diversity of habitats depend in the first place upon the water regime affected by the Neretva River. Owing to many underground karst streams of the basin, in the part adjacent with the surrounding limestone terrain, there is a large number of springs carrying large amounts of water, especially in winter. The ground water coming from this adjacent area supplies numerous streams, lakes and cavities. Many caves and other underground habitats in the surrounding karst are home for rich fauna with many endemic species.
An important factor affecting the delta is the sea, and the bodies of brackish water present special habitats which contribute additionally to the biological diversity of this whole area. Aquatic habitats, together with large reed-patches, wet meadows, beaches, sand-banks and saltmarshes, as well as the adjacent karst overground and underground, present a wide variety of habitats, that is the basis for an adequately wide variety of plant and animal life.
Due to its high biological production, the Neretva mouth is a feeding place for many kinds of fish.The delta, lagoons and bodies of brackish water present fry ponds for fish and crayfish which spend the rest of their lives in fresh or salt water. They are also inlets and outlets for fish migrations. At the time when many lagoons have not been drained yet, the importance of the mouth for fish feeding and spawning - especially that of the Modric lake - was much higher. Even today, fishing is an important activity of the local population, but mainly not the principal one. They catch mostly mullets and eels. Unfortunately, fishing is made in an uncontrolled and unsystematical manner and by inadequate methods, that endangers the already reduced fish stocks even more.
In the Neretva Delta, as many as 310 bird species, of which 115 nesting birds, have been registered. The area is important in the first place as a resting place during bird migrations and for wintering of birds. The mouth with its shoals and sand banks is of greatest importance for migration of waders, terns and gulls. Reed-patches and bodies of water are important for migration and wintering of ducks, and reed-patches, surrounding meadows and shrubs for various song-birds. Here nest some of the European endangered species, such as bittern, ferruginous duck and Kentish plover, the latter building its nest on sandy beaches at the Neretva mouth, then bearded parrotbill for which this is the only nesting site in the Croatian littoral. Reed-patches are important also for nesting of rails and various kinds of crakes and warblers.
After extensive land-reclamation works, the situation for waterbirds in the Neretva Delta became worse (loss of habitat, intensive land cultivation, excessive hunting). The number of birds decreased considerably, although the number of species remains very high and important. As far as the bird species composition and the importance of the delta for bird migration and wintering are concerned, this area is still of international importance. With adequate protective measures and with the management plan which would include revitalisation of some habitats and a severe regulation of hunting, the situation might improve considerably.
The Lower Neretva valley has a rich monumental heritage witnessing the presence of man in this area for thousands of years. Turning of wetland into fertile land and establishment of transportation routes to the hinterland created the conditions for the development of settlements. Many prehistorical fortifications and settlements as well as tumuluses are scattered on high or low grounds along the Neretva River. This area seems to have been inhabited by Illyrian tribes as far back as in the Iron Age. In the 4th century B.C., the ancient Greeks founded an emporium (the port) here, which developed into the well known market town Narona, today Vid near Metkovic. All over the delta around Narona there were suburbs and estates the remnants of which are now covered by the marsh and deposited sediments. Many monuments from the Roman time are present, too, such as city walls with towers, Roman villas, mosaics, epitaphs. At the time of the emperor Augustus, Narona was an administrative centre. In 1996, in the centre of Vid the remnants of the main square temple (Augusteum) were excavated containing 16 statues of gods and godesses among which dominant is the impressive 3 m high statue of the emperor Augustus in his imperial uniform.
The Christianity can be traced in the Lower Neretva valley as far back as from the middle of the 5th century. Of the Early Christian sacral monuments dominant is St Vid's Basilica with its very well preserved baptisery at the place of the present church in Vid.
The medieval monuments are few. During the Turkish invasion at the end of the15th century, several churches were destroyed and the memory of those times is kept alive by the impressive fortress Norinska kula situated at the mouth of the small Norin River into the Neretva River. Due to frequent wars in this area, no significant monuments from the time of the City/State of Venice have been left.
The traditional architecture in the Lower Neretva valley has its specific characteristics and makes part of the monumental heritage of this region, too. However, typical old houses are more and more abandoned and either become ruins or are adapted in an inadequate way.
It remains to make a proper evaluation of the importance of the archeological sites and monumental heritage in the Neretva Delta and then to make use of the outstanding possibilities which open in terms of tourism.
Space use in Lower Neretva valley
The man began to conquer the wetland and to adapt it to his needs in the 19th century. More extensive regulations of the Neretva River started in the 1880's to establish the navigable waterway to Metkovic. The first form of land-reclamation was the so-called jendecenje - digging of channels to drain marsh soil and spreading the dug earth over lots of land thus obtaining arable land. Hunting, fishing, raising of cattle which managed to survive on the marsh vegetation, wine growing and scanty soil cultivation, that was the way of life in the Lower Neretva valley until some fifty years ago. Everything depended upon cycles and movement or water, the main means of communication in this area being a special boat trupa. These small boats were used to fish, to harvest grapes and to drive cattle which often had to force its way through water by swimming. It was in trupas that wedding and funeral processions passed the Neretva.
The extensive land-reclamation works completed in the 1960's brought drastic changes. Application of modern land-improvement methods, intensification of agriculture and introduction of new crops resulted in the improvement of the standard of living of people in the Neretva Delta. The prevailing wetland landscape changed into the farmland one, with mainly mandarine plantations.
The adverse effects of human activities on the natural values are the same all over the Lower Neretva valley. Today, the population is concentrated in several larger settlements. Metkovic, Opuzen and Ploce are larger centres in the Republic of Croatia, and Capljina in Bosnia and Herzegovina.
In the 1960s, in cooperation with the experts of the international organisation FAO, 5.376 ha of marshes and lagoons in the Neretva Delta were reclaimed. After the establishment of the state-owned and run enterprise PIK Neretva, the newly reclaimed arable land gradually became cultivated. The marsh was turned into plantations, mainly of mandarines. The water regime here as well as the vicinity of the sea (soil salting) required a permanent application of very complex and expensive hydraulic land-reclamation and improvement measures to maintain the existing conditions. All this, of course, to the detriment of marsh habitats the reduction of which was followed by the decrease of the once immense abundance of fish and bird life.
In the last few years, after dissolution of big PIK Neretva and in the conditions of difficult economic situation, any land-improvement works ceased and the agricultural activities decreased. Because of unsettled property right relations, the development of agriculture was unsystematic and uncontrolled. New arable lands were conquered illegally at the expense of marsh habitats, while the others due to their neglected state turned into marshes again and became overgrown with natural vegetation. Moreover, pesticides and artificial fertilizers, which as direct or indirect water pollutants threaten the aquatic and marsh flora and fauna, are used without any control.
Water management activities affected considerably nature in this area in the last decades, too. These activities were closely connected with the development of the agriculture (the land-reclamation) and with the regulation of many streams for the purpose of flood control.
Moreover, a considerable water regime disturbance was caused by the construction of five upstream hydro-electric power plants in the territory of BiH. Their respective dams keep water and sediments thus causing frequent and rapid water level changes or water shortage, especially in summer.
While agricultural and water management activities threaten in the first place the aquatic and marsh habitats, uncontrolled hunting and fishing present a threat for the fauna of this region. The number of birds and fish, which in the past were essential for survival of population in this area, is reduced considerably. The hunting and fishing tranditions are deep-rooted in the local people, although they are aware that birds and fish are endangered and need to be protected. Poaching is frequent, and burning of reed-patches to get open space for hunting occurs often, too. Similar problems exist in respect to fishing. Nets are placed in channels as barriers to prevent movement of fish. Besides, fishing is done inside the reserve at the Neretva Delta in the zone where it is forbidden.
Unfortunately, the outstanding potential of this area in terms of the tourism is almost unused. It seems that the development of tourism in conjuction with the protection of natural resources might characterize the future development of the Lower Neretva valley.
Nature Conservation - Future of the Lower Neretva Valley?
The natural and landscape values in combination with the rich and highly valuable cultural and historical heritage might become the basis for the development of the whole of the Lower Neretva valley. Such development has to be planned integrally for a wider transboundary region.
Hutovo blato is already protected as nature park, and the Neretva Delta in the Republic of Croatia is anticipated for protection of the same category. Such protection, while fully respecting the requirements of development, seeks to protect the area from the excessive economic exploitation and construction. Human activities are placed in the frameworks of certain general conditions and guidelines aiming to preserve the main natural values which present the basis for the development of this area.
The nature conservation is based on zoning, i.e. on determining the most preserved and valuable zones of nature which require a severe conservation regime, and the surrounding zones with a marked anthropogenetic impact. All area must be managed integrally to ensure the conformity of activities of all users of this area with a special management plan.
In any case, in the Neretva Delta it is essential to stop the destruction of the remaining marsh habitats and to revitalise those already destroyed whose revitalisation is possible.
The combination of the marshy - coastal - mountainous environment and the cultural and historical heritage on one side with the singularities of the local way of living on the other side must be used as a potential for the development of tourism in the region.
So far, no concept of tourism development in this region has been prepared. However, in order to preserve natural values as the basis for such development, it is evident that mass tourism involving construction of large hotels and tourist complexes should not be envisaged. Instead, excellent possibilities for the day-trip tourism exist here with excursions to the protected parts of nature, including observation and taking pictures of birds, in combination with visits to archeological sites and cultural and historical monuments.
Moreover, this area has a pronounced potential for the development of ecological farming, which in an appropriate manner could be included in its overall development concept.
The public opinion polls carried out in the Neretva Delta in the past few years show a significant progress in the development of public awareness as to the necessity to preserve nature as the potential for the future development. Several non-governmental associations active in the field of nature conservation contributed a great deal to educate the young and to build the ecological awareness in general in this region.