Lithuanian coastal site
Silute, Klaipeda, Neringa and Palanga Municipalities, Klaipeda Region, Lithuania
about 90,000 ha
A major system of coastal wetlands, including near-shore marine waters, Lithuanian part of the Curonian Lagoon and of the Curonian Spit, and the Nemunas River delta area. The site is a representative and unique example of a coastal wetland complex characteristic of the Eastern Baltic Region.
The brackish Curonian Lagoon was formed in the early post-glacial period, about 7,000 years ago, when a sandy Curonian Spit separated the shallow bay from the Baltic Sea. It is the largest lagoon in the SE Baltic region (the total area – 1,584 km²). The total area of the Curonian Lagoon basin is about 100,500 km² while the total water volume is about 6 km³. It is a shallow, brackish lagoon, in the northern part connected with the sea through a narrow Klaipeda strait. The lagoon ecosystem is influenced by fresh, brackish and saline water masses. Water salinity in the northern part of the lagoon may fluctuate between 0.1‰ and 7‰. Annual input of fresh water of the Nemunas River is about 21 km³, while the annual influx of saline water from the Baltic Sea – about 5 km³. Water pH in the lagoon is 7.5–8.9 and the transparency of water column is 0.2–1 m. Sandy and sand-mud bottom dominates in the lagoon within the boundaries of the site.
The Curonian Spit separates two water basins: the saline Baltic Sea and the brackish Curonian Lagoon. The narrow strip of land, composed of eolian and marine sands, is distinguished by the unique in this region ridge of drifting sandy dunes.
Sandy sediments, mud, gravel, stones or moraine cover the seabed in the marine near-shore zone. Intensive transport of seabed sediment occurs in this coastal zone. Up to 400,000 m³ of sand are annually drifted along the Lithuanian coast. Water salinity varies from 4‰ to 7‰. The exchange of the water between the brackish Curonian Lagoon and the open sea impacts the whole costal ecosystem.
The Nemunas River delta lowland was formed during the last glacial period. It is one of the very few natural or moderately changed estuaries, remaining in the Baltic Region. The total area of the delta lowland is about 2,000 km². The surface of the Nemunas River delta is flat, banks of all rivers and streams are low, in many sites surrounded by marshes and bogs. Numerous rivers, streams and canals intersect in the delta area.
Lithuanian coastal site is distinguished by diverse habitats (marine waters, brackish lagoon, freshwater delta, sandy dunes, vast seasonally flooded meadows, rivers, lakes, pools, raised bogs, fishponds, swamp forests, etc.). A very high biomass production and large biodiversity of communities was recorded in this territory. Many rare in Europe types of habitats, listed in the EU Habitats Directive are characteristic of the site. Particularly valuable habitat types of the site are estuaries, coastal lagoons, dunes, active raised bogs, deciduous swamp woods, bog woodland and alluvial forests. They are of crucial importance for maintenance of biodiversity in the region. Rare and protected plant communities, characteristic exclusively of coastal habitats, distinguish the site. About 500 vascular plant species were recently recorded in the site.
Fauna of the site is specific in many respects due to the habitats characteristic of marine and brackish waters, freshwater estuaries, floodplains, large areas of almost intact open raised bogs and large swamp forests. This large natural complex of wetlands supports many rare and vulnerable species, listed in the EU Habitats and Birds Directives. The territory is one of the most important stopover and wintering sites for waterbirds in Europe and the key breeding site of rare and endangered species of birds. More than 300 bird species were recorded in the site (among them – about 200 breeding species) in recent years. The site supports 54 nesting bird species listed in the Annex I of the EU Birds Directive. More than 100,000 birds are ringed annually in the Ventes Ragas Ornithological Station, which is situated on the coast of the Curonian Lagoon. The site is the key path for the migratory fish species to the Nemunas River basin and important spawning ground of several fish species. More than 60 fish species inhabit the site. The territory supports several rare in Europe fish species, listed in the Annex II of the EU Habitats Directive. The Curonian Lagoon is one of the most productive water basins in Northern Europe with an estimated annual fish yield of over 32 kg/ha. A very high biomass production and large biodiversity of benthic communities are characteristic of the site. Freshwater, brackish and marine species inhabit the site. More than 2,000 insect species from 7 orders were identified at the Baltic seashore.
The main threat in the area is high pollution level. The major sources of pollution are wastewaters and harmful substances from industry, agriculture and urban areas of the Nemunas River basin. New oil developments can cause major impacts on the whole coastal ecosystem. Due to high eutrophication level, heavy bloom of microalgae is a frequent phenomenon in the inshore marine areas and in the Curonian Lagoon. Conflicts between commercial fishery in the site and waterbirds have been increasing in recent years. Most natural seasonally flooded meadows of the site have been transformed into cultivated meadows since the early 20th century. Changes of the natural hydrological system have resulted in local drying of forest stands and changes in valuable plant communities.
The majority of the site is protected as the Nemunas River Delta Regional Park (area - about 27,000 ha), the Pajuris Regional Park (5,070 ha), the Kursiu Nerija National Park (26,400 ha) and several Nature Reserves. The Kursiu Nerija National Park is included in the list of the UNESCO World Cultural and Natural Heritage. The Nemunas River Delta Regional Park is the designated Ramsar site. Most human activities are regulated in protected territories of the site. The planned Natura 2000 network will cover large areas of the site.
Initial data on geology, palaeontology, hydrology, ecological communities, fauna and flora of the site are available since the 19th century. Geomorphological processes of the site are studied since the end of the 19th century. A detailed research of plant communities in Aukstumale raised bog (part of the Nemunas River delta) was performed more than 100 years ago. Vegetation communities of the Curonian Spit and of the continental part of the Lithuanian seacoast were investigated since the 1930s and in the seasonally flooded meadows of the lower Nemunas River – since the 1950s. Ornithological Station “Ventes Ragas” was established in the site in 1929.
The first large-scale multidisciplinary research program in the Curonian Lagoon was implemented in the 1950s. It has resulted in a monograph on the geology, geography, hydrology, flora and fauna of the site.
Several international multidisciplinary research programs were implemented in near shore Baltic waters, in the Curonian Lagoon and in the Nemunas River Delta during the last decades. Large-scale investigations were performed as part of the EU 5th Framework, NATO, HELCOM and other international programs. Institute of Ecology of Vilnius University, Institute of Geology and Geography, Institute of Botany, Klaipeda University and other research organizations participated in long-term investigations of various abiotic and biotic parameters of the site. These studies have resulted in a series of monographs and numerous publications.
The Baltic Sea: coastal dynamics and palaeography. 1990-1993. Vilnius: Institute of Geography.
Berendt G.1869. Die Geologie des Kurischen Haffs seiner Umgebung. Konigsberg.
Dagys M. 1997. Possible impact of gill net fishing on wintering birds in Lithuanian inshore waters of the Baltic Sea. Acta Zoologica Lituanica, Ornithologica, 6: 112–117.
Jankevicius K. (ed.) 1959. Curonian Lagoon. Results of complex investigations. Vilnius (in Lithuanian).
Galkus A., Joksas K. 1997. Sediments in tranzit aquasystem. Vilnius (in Lithuanian)
Gasiunas I. 1961. Benthic communities of the Curonian Lagoon and their relationship with the Baltic Sea. Procl. Lithuanian Acad. Sci. Ser.C, Vol.3: 129–145 (in Lithuanian).
Gudelis V.1998. The Lithuanian offshore and coast of the Baltic Sea.Vilnius.
Gudelis V., Jemeljanovas E. (eds) 1976. Geology of the Baltic Sea. Vilnius (in Russian).
Gelumbauskaite L.-Z. 2003. On the morphogenesis and morphodynamics of the shallow off the Curonian Spit. Baltica 16: 37-42.
Kadunas V., Budavicius R., Gregorauskiene V., Katinas V., Kliaugiene E., Radzevicius A., Taraskevicius R. 1999. Geochemical atlas of Lithuania. Vilnius: Institute of Geology.
Krisciunas J. (ed.) 1955. Seasonally flooded meadows of the lower Nemunas River. Vilnius (in Lithuanian).
Lazauskiene L. (ed.) 1994. Oil terminal in Butinge and ecology. Vilnius.
Maniukas J. (ed.) 1977 – 1978. The Nemunas River. Vol. 1-2. Vilnius: Mokslas (in Lithuanian).
Paul K.1944–1953. Morphologie und Vegetation der Kurischen Nehrung. Haale.
Stankeviciute J. 2000. The structure, chronology and succession of vegetation of Lithuanian sandy coastal areas. Manuscript. Vilnius.
Stankevicius A. (ed.) 1998. Environmental state of the Curonian Lagoon and of the Baltic Sea. Klaipeda (in Lithuanian).
Svazas S., Drobelis E., Balciauskas L., Raudonikis L. 1999. Important wetlands in Lithuania. Vilnius: OMPO Vilnius.
Svazas S., Kozulin A., Grishanov G., Maximenkov M., Rasomavicius V., Raudonikis L., Baichorov V., Skuratovich A., Balciauskas L., Drobelis E., Grishanov D. 2004. Important transboundary Belarusian-Lithuanian and Lithuanian-Russian wetlands. Vilnius: OMPO Vilnius & Institute of Ecology of Vilnius University.
Zilinskas G., Jarmalavicius D., Minkevicius V. 2001. Eolian processes in the seacoast. Vilnius.
Zydelis R. Habitat selection of waterbirds wintering in Lithuanian coastal zones of the Baltic Sea. Summary of Doctoral Dissertation. Vilnius: Institute of Ecology.
Weber C. 1902. Über die Vegetation und Entstehung des Hochmoors von Augstumal im Memeldelta. Berlin.
Zalakevicius M., Svazas S., Stanevicius S., Vaitkus G. 1995. Bird migration and wintering in Lithuania. Acta Zoologica Lituanica 2. Monograph. Vilnius.
The main fields of research:
Trends in the Baltic Sea coast dynamics;
Dynamics of the main dune ridge of the Curonian Spit;
Long-term development of the Curonian Lagoon and of the Nemunas River delta;
Geo-ecological state of coastal ecosystems;
Biological effects of environmental pollution in coastal ecosystems;
Long-term changes of ecological communities of the site;
Production and population dynamics of aquatic invertebrates;
Biological role and dynamics of fish populations;
Ecology of wintering and migratory populations of waterbirds;
Anthropogenic impacts on waterbirds, conflicts with commercial fishery;
Integrated coastal zone management;
Dynamics of the wetland ecosystem under anthropogenic impacts and global climate change;
Cross-border research on biodiversity of the Nemunas (Neman) River delta (in collaboration with the Kaliningrad State University).
Data on biodiversity of the site (long-term data on populations of aquatic invertebrates, fish and waterbirds, on distribution of all rare species, etc.) are compiled in databases of the Institute of Ecology of Vilnius University. GIS-format long-term land cover changes in the Lithuanian coastal zone (obtained from Landsat MSS images) are compiled in the Database of the GIS Group of the Institute of Ecology of Vilnius University. Long-term data on key abiotic parameters of the site are stored in the databases of the Institute of Geology and Geography.
The Nemunas River delta is shared by Lithuania and Russia. The Institute of Ecology of Vilnius University and the Kaliningrad State University (in collaboration with other research institutes of both countries) coordinate the cross-border integrated research program on dynamics of this ecosystem under anthropogenic impacts and global climate change.
Dr Mindaugas Dagys, Institute of Ecology of Vilnius University; e-mail: firstname.lastname@example.org
Dr Valerijus Rasomavicius, Institute of Botany; e-mail: email@example.com
Dr Petras Sinkunas, Institute of Geology & Geography; e-mail: firstname.lastname@example.org