Description of the project site

Physical features

The site is located in the Nemunas River delta lowland. The delta lowland was formed during the last glacial period by the melting glacier of the lower Nemunas River. Later glacial lakes and accumulation of estuarine deposits have transformed the delta lowland. The total area of the delta lowland - about 2,000 km². The Nemunas River (one of the largest rivers in the region with a total length of 937 km), falls into Curonian Lagoon forming a wide delta. Many other rivers, small streams and a network of canals intersect the delta. Estuaries of several other rivers (the Minija, Tenenys, Sysa, etc.) are also located in the Nemunas River delta lowland. 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. Certain territories of the site are located up to 1,5 m below the sea level. Spring floods in the delta lowland last from 57 to 62 days, with water level rising up to 2-3 m. Coastal meadows, pastures and forests (up to 30,000 ha) are flooded in winter and spring. The flood control is performed by means of a system of polders and dams. Heavily waterlogged territories form more than 60% of the total area of the site. Rusne Island (the largest in Lithuania with an area of 45,2 km²) is located in the delta area. There are 5 large raised bogs in the delta area. The largest is Aukstumala raised bog (area - about 3,000 ha). There are many small lakes and pools (up to 2-4 m deep) in open raised bogs. A large Lake Kroku Lanka (the area - 7,8 km²) is located in northern part of the delta area. It has been formed in a former bay of the Curonian Lagoon, separated from the main basin by sediments of the Nemunas River.. A dense network of drainage canals has been formed in wet forests of the site. Many of these canals are abandoned or dammed due to beaver Castor fiber activity. Two large Kintai and Rusne fishpond complexes (with a total area of about 1,500 ha) were constructed in the site in the 1970s - 1980s.

The adjacent Curonian Lagoon was formed in the early post-glacial period, about 7,000 years ago, when a sandy spit separated the shallow bay from the Baltic Sea. It is the largest lagoon in the Southeast Baltic Region (the total area - 1,584 km²).The total water volume in the lagoon - about 6 km³, the average depth in the delta area - about 1 m. In the delta area it is an almost fresh-water body with a mean salinity of 0,3 permilles. The basin of the Nemunas River accounts for 98% of the drainage area of the lagoon.

Ecological features

Forests cover about 50% of the total area of the site. Most valuable are permanently flooded Carici elongatae-Alnetum glutinosae, Circaeo-Alnetum glutinosae communities with very diverse species composition of the field layer dominate in this territory. Species characteristic of fens (Iris pseudacorus, Sium latifolium, Equisetum fluviatile, etc.) are common in heavily waterlogged forests. Dry pine forests (Cladonio-Pinetum, Peucedano-Pinetum sylvestris) cover sandy and hilly areas of the site. Spruce forests (Melico nutantis-Piceetum) cover smaller areas than pine forests. Broad-leaved deciduous forests ((Querco-Fagetea) occur only fragmentary. Salicetea purpurea communities with Salix alba, S. triandra, S. viminalis, S. purpurea are common along banks of the Nemunas River. Mires cover about 20% of the total area of the site. Many of them are partly drained, but large areas of raised bogs have maintained natural hydrological regime. Ledo-Pinetum sylvestris communities with Ledum palustre, Vaccinium uliginosum,  Betula pendula, B. pubescens occur at peripheries of raised bogs. Sphagnetum magellanici communities with Sphagnum magellanicum, Sphagnum rubelum, Sphagnum cuspidatum, Rhynchospora alba and Baeothryon cespitosum dominate in open areas of raised bogs. Betula pendula, B. pubescens, Pinus sylvestris, Calluna vulgaris, Vaccinium uliginosum, Rubus chamaemorus and Ledum palustre cover drier areas. Rare in the region Eriophoro-Trichophoretum cespitosi communities occur in open patches of raised bogs. Caricetum limosae communities cover banks of pools and small lakes, while Sphagno tenelli-Rhynchosporetum communities can be encountered in depressions of raised bogs. Fens occur only fragmentary at peripheries of raised bogs. Equisetum fluviatile, Lysimachia vulgaris, Lythrum salicaria, Solanum dulcamara, Comarum palustre and Iris pseudacorus predominate on communities of fens.

Most meadows of the site are seasonally flooded. Molinio-Arrhenatheretea elatioris communities dominate in this territory. Alopecuretum pratensis and Festucetum pratensis meadows are characteristic of the site. Deschampsietum cespitosae and Festuco-Cynosuretum cristati communities occur in waterlogged areas. Characteristic only of this region Triglochin maritimum can be encountered in Caricetum distichae community. Small patches of Acoretum calami are characteristic of permanently flooded depressions. Rare in the region Gladiolus imbricatus can be encountered in Molinietum caeruleae communities, which occur only fragmentary. Rare Scutellaria hastifolia occur in Arrhenatheretum medioeuropaeum community. Spergulo vernalis-Corynephoretum canescentis communities with rare in the region Epipactis atrorubens can be encountered in dry sites not affected by seasonal floods. 

Dense reed stands (Phragmitetum australis) cover vast areas located along the coast of Curonian Lagoon. Scirpetum lacustris communities are also abundant, while Magnocaricion elatae occur only in shallow areas. In certain areas Phragmitetum australis communities are up to 300 m wide. Potemogeton perfoliatus, P. natans, Nuphar lutea, Sagittaria sagittifolia and Hydrocharitetum morsus-ranae, Lemnetum trisulcae communities dominate in shallow waters of the lagoon and in bays of the Nemunas River delta. 

Spirodeletum polyrhizae, Stratiotetum aloidis communities are characteristic of numerous small lakes and old riverbeds of the delta area. Sphagno-Utricularion communities with Nuphar luteum, Sphagnum cuspidatum, Warnstorfia fluitans can be encountered in small dystrophic lakes located in raised bogs.

Valuable habitats

The Nemunas (Neman) River delta area is distinguished by many rare in Europe types of habitats, listed in the EU Habitats Directive:

1130 Estuaries

1150 Coastal lagoons

2330 Inland dunes with open Corynephorus and Agrostis grasslands

3150 Natural eutrophic lakes with Magnopotamion or Hydrocharition -type vegetation

3160 Natural dystrophic lakes and ponds

3260 Water courses of plain to montane levels with the Ranunculion fluitantis vegetation

3270 Rivers with muddy banks with Chenopodion rubri and Bidention vegetation 

6120 Xeric and calcareous grasslands

6410 Molinia meadows on calcareous, peaty or clayey soils (Molinia caeruleae)

6430 Hydrophillous tall herb fringe communities of plains

6450 Northern boreal alluvial meadows

6510 Lowland hay meadows (Alopecurus pratensis)

7110 Active raised bogs

7120 Degraded raised bogs still capable of natural regeneration

7140 Transition mires and quaking bogs 

7150 Depressions on peat substrates of the Rhynchosporion

9010 Western taiga 

9020 Fennoscandian hemiboreal natural old broad-leaved deciduous forests (Quercus, Tilia, etc.)

9050 Fennoscandian herb-rich forests with Picea abies 

9080 Fennoscandian deciduous swamp woods 

9160 Sub-Atlantic and medio-European oak or oak-hornbeam forests of the Carpinion betuli

91E0 Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae)

91D0 Bog woodland

According to the diversity of valuable types of habitats this wetland complex is the most important in Lithuania. Particularly valuable habitat types of the site are estuaries, coastal lagoons, active raised bogs, deciduous swamp woods, bog woodland and alluvial forests. They are of crucial importance for sustaining of the natural water regime and for maintenance of biodiversity in the region. The wetland complex is also distinguished by rare and protected plant communities, characteristic exclusively of coastal floodplains.

The wetland complex hosts 21 rare in the region plant species, included into the Red Data Book of Lithuania: Allium scorodoprasum, Bolboschoenus maritimus, Dactylorhiza fuchsii, D. incarnata, D. longifolia, Drosera intermedia, Epipactis atrorubens, Gladiolus imbricatus, Juncus gerardii, Listera cordata, Nymphaea alba, Nymphoides peltata, Polemonium caeruleum, Salix repens, Scutellaria hastifolia, Sphagnum molle, S. papillosum, S. subnitens, Trichophorum cespitosum and Triglochin maritimum.

The site is distinguished by vulnerable Nymphoides peltata, characteristic of the Nemunas River delta. Abundant population of Dactylorhiza fuchsii was recorded in Zalgiriai swamp forest and in Aukstumala raised bog. Protected in Lithuania Scutellaria hastifolia can be encountered in natural meadows of the site bordering swamp forests. Rare in the region Allium scorodoprasum is rather common in wet meadows bordering continental dunes, while Epipactis atrorubens covers dry hilly patches of the site, not affected by seasonal flooding. Certain rare species recorded in the site (Triglochin maritimum, Juncus gerardii) in Lithuania occur exclusively in coastal floodplains. The wetland complex is the eastern edge in Lithuania of raised bog communities with deergrass Baeothryon caespitosum.

Rare fauna species

Fauna of the site is specific in many aspects due to habitats characteristic of coastal estuaries, floodplains, large areas of almost intact open raised bogs and large swamp forests. 

This large natural complex of wetlands is of a crucial importance for maintaining of biological diversity in Europe. It supports many rare and vulnerable species, included into the Red Data Books of Russia and Lithuania, and listed in the EU Habitat and Bird Directives. 

Invertebrates

A very high biomass production and large biodiversity of benthic communities are characterised of the site. Representatives of fresh-water, brackish and marine species inhabit the site. The distribution of bottom animals is very scattered, depending on the environmental variations in various zones. The most abundant species are the deposit-feeders and filter feeders like Nereis diversicolor, Oligochaeta warms, midges Chironomidae and bivalve molluscs Dreissena polymorpha. Typical representatives of brackish waters are crustaceans Corophium voluntator, Neomysis vulgaris, Crangon crangon and molluscs Hydrobia ventrosa, Potamopyrgus jenkensi.

Two rare species of insects included into the Red Data Book of Lithuania were recorded in the wetland complex: Agonum ericeti (Coleoptera) and Papilio machaon (Lepidoptera). Beetles Agonum ericeti were found in raised bogs of the site. Rare in the region Anax imperator (Odonata), included into the Red Data Books of Lithuania, was found in the Nemunas River delta.

Amphibians and reptiles

The site is important for rare species of amphibians. Fire-bellied toad Bombina bombina inhabits small pools located in old riverbeds along the Nemunas River. It is included into the Red Data Book of Lithuania and listed in the Annex II of the EU Habitat Directive. Running toad Bufo calamita, included into the Red Data Books of Lithuania.

Among reptiles, viviparous lizards Lacerta vivipara, grass snakes Natrix natrix and common vipers Vipera berus are particularly abundant in certain areas of the site. 

Fishes

The delta area is the key path for migratory fish species to the whole Nemunas River basin. Shallow bays of Curonian Lagoon and estuaries of rivers are important spawning grounds of several fish species.

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. About 50 fish species inhabit the site. Carp fish (Cyprinidae) species dominate in the delta area (22 species). Most fish species are of a high commercial value. 

The territory supports several rare in Europe species, listed in the Annex II of the EU Habitat Directive: Petromyzon marinus, Lampetra fluviatilis, Lampetra planeri, Acipenser sturio, Cottus gobio, Misgurnus fossilis and Salmo salar. 

The Nemunas River delta also holds several other rare species, listed in the Annex II of the Bern Convention: Aspius aspius, Pelecus cultratus, Rhodeus sericeus and Silurus glanis.

Mammals

The site holds several rare in the region species of mammals, protected in Lithuania and in the European Union.

Rare and protected in Lithuania species of bats Myotis brandti, Myotis dasycneme, and Barbastella barbastella inhabit the site. Two latter species are of European conservation concern, listed in the Annex II of the EU Habitat Directive. Several rare bat species included into the Lithuanian Red Data Book were recently ringed in Ventes Ragas Ornithological Station during the migration periods: Nyctalus noctula, Nyctalus leisleri, Pipistrellus pipistrellus, Eptesicus nilssoni, Eptesicus serotinus and Vespertilio murinus.

The territory supports several other species of mammals protected in Lithuania: birch mouse Sicista betulina, ermine Mustela erminea, lynx Lynx lynx and otter Lutra lutra. Lynx and otter are listed in the Annex II of EU Habitat Directive.

Abundant population of beaver Castor fiber (up to 200 individuals) is characteristic of the site. Beaver is listed in the Annex II of EU Habitat Directive. 

The whole delta area (including also its Russian part) holds up to 15 wolfs Canis lupus, listed in the Annex II of EU Habitat Directive.

It is the key area for moose Alces alces in Lithuanian coastal region.

Birds

More than 300 bird species were recorded in the site (among them - about 200 breeding species) in recent years.

The Nemunas River delta area is one of key nesting sites of rare and vulnerable bird species in Europe. The site supports 55 nesting or probably nesting bird species included into the Red Data Book of Lithuania and 53 - listed in the Annex I of the EU Bird Directive.

* - possible breeder; breeding of the species has not been confirmed

The wetland complex is of crucial importance for certain globally threatened species. Floodplains of the site holds up to 50 nesting pairs of Great Snipe Gallinago media and up to 40 pairs of Aquatic Warbler Acrocephalus paludicola. The wetland complex is the most important nesting ground of Great Snipe in Lithuania. Corncrake Crex crex is a common breeder in wet meadows with up to 300 pairs counted. Particularly high nesting densities of Corncrake (up to 18 pairs/100 ha) were recently recorded in certain habitats of the site. Potential breeders of this wetland complex are Spotted Eagle Aquila clanga and Ferruginous Duck Aythya nyroca. Single pairs of both species were recorded during the breeding season in habitats suitable for nesting.

The Nemunas River delta is the regional nesting center of many rare bird species.

Old wet forests of the delta (including its Russian part) site holds 5-7 pairs of Black Stork Ciconia nigra, 6-9 pairs of White-tailed Eagle Haliaeetus albicilla, 10-14 pairs of Lesser Spotted Eagle Aquila pomarina, 8-10 pairs of Black Kite Milvus migrans, 3-5 pairs of Eagle Owl Bubo bubo, 4-6 pairs of Ural Owl Strix uralensis, 20-30 pairs of Black Woodpecker Dryocopus martius, 4-5 pairs of White-backed Woodpecker Dendrocopos leucotos, etc. Local breeding populations of White-tailed Eagle, Lesser Spotted Eagle, Eagle Owl and Ural Owl are the largest in Lithuania.

Large mires and wet meadows of the site (including its Russian part) support 10-12 pairs of Montagu's Harrier Circus pygargus, 2-3 pairs of very rare in this region Hen Harrier Circus cyaneus, 20-30 pairs of Black Grouse Tetrao tetrix, 35-40 pairs of Common Crane Grus grus, 100-130 pairs of Spotted Crake Porzana porzana, 4-6 pairs of rare in the region Golden Plover Pluvialis apricaria, 3-5 pairs of Wood Sandpiper Tringa glareola, up to 50-70 pairs of Redshank Tringa totanus, 15-20 pairs of Dunlin Calidris alpina, 50-70 pairs of Ruff Philomachus pugnax, 80-100 pairs of Black-tailed Godwit Limosa limosa, 10-15 pairs of Curlew Numenius arquata, 4-7 pairs of Short-eared Owl Asio flammeus, etc. Local breeding populations of Montagu's Harrier, Spotted Crake, Redshank, Dunlin, Black-tailed Godwit and Ruff are the largest in Lithuania.

Shallow inshore waters of the Nemunas (Neman) River delta, sandy islands and large fishponds of the site hold regionally important breeding populations of waterbirds. Up to 20-30 breeding pairs of Black-necked Grebe Podiceps nigricollis and of Bittern Botaurus stellaris, 40-50 pairs of Greylag Goose Anser anser, 5-8 pairs of Shelduck Tadorna tadorna, 20-30 pairs of Gadwall Anas strepera, 150-200 pairs of Shoveler Anas clypeata, 10-15 pairs of Avocet Recurvirostra avosetta, 4-7 pairs of Oystercatcher Haematopus ostralegus, up to 200 pairs of Common Tern Sterna hirundo, up to 100 pairs of Little Tern Sterna albifrons, up to 500 pairs of Black Tern Chlidonias niger, etc. were recently recorded in the whole delta area. It is the only nesting site of Avocet in Lithuania. Local breeding populations of Bittern, Greylag Goose, Gadwall, Shoveler, Little Tern and Black Tern are the largest in Lithuania.

Abundant breeding waterbirds in this territory are Great Crested Grebe Podiceps cristatus, Little Grebe Tachybaptus ruficollis, Mute Swan Cygnus olor, Mallard Anas platyrhynchos, Teal Anas crecca, Garganey Anas querquedula, Pochard Aythya ferina, Tufted Duck Aythya fuligula and Coot Fulica atra. Common and abundant breeding species of waders are Little Ringed Plover (Charadrius dubius, Lapwing Vanellus vanellus, Green Sandpiper Tringa ochropus, Common Sandpiper Actitis hypoleucos and Common Snipe Gallinago gallinago.

Villages and settlements of the wetland complex are important nesting grounds of White Stork Ciconia ciconia, with up to 200 nesting pairs counted in the whole delta territory with adjacent areas.

The delta area with adjacent floodplains is the most important stop-over site for numerous species of waterbirds in the South Eastern Baltic Region. Internationally important concentrations of 18 waterbird species (exceeding the 1% Ramsar threshold) were recently recorded in the site.

Flooded coastal meadows of the delta area are key staging sites for population of Whooper Swan Cygnus cygnus during spring migration in Europe, with up to 6,800 birds (11% of individuals of the whole NW Europe population) recently recorded during one census. Very large staging flocks of the Bewick's Swan Columbianus columbianus bewickii are also characteristic of floodplains, with up to 3,200 swans (11% individuals of NW Europe population) recorded.

Floodplains surrounding the delta are the key stop-over sites of Greater White-fronted Geese Anser albifrons in the Baltic Region, with more than 100,000 birds counted.. Internationally important staging flocks of Bean Goose Anser fabalis (up to 6,000 birds), Greylag Goose (up to 4,000 birds) and of Barnacle Goose Branta leucopsis (up to 2,600 birds) were also recorded in the delta area in recent years. The site supports migratory population of the globally threatened Lesser White-fronted Goose Anser erythropus. Small staging groups of Lesser White-fronted Geese in recent years were irregularly recorded in the site.

The delta area is of crucial importance for migratory populations of ducks, with up to 5,000 Northern Pintails Anas acuta, 20,000 Wigeons Anas penelope, 3,000 Gadwalls, 41,000 Pochards Aythya ferina, 38,000 Tufted Ducks Aythya fuligula and 4,500 Smews Mergellus albellus counted during one census. Small staging flocks of the globally threatened Ferruginous Duck were irregularly observed in the site.

The site is the main stop-over ground of migratory Common Cranes in the coastal region of Lithuania, with up to 3,500 birds counted in raised bogs and wet meadows of the territory.

The wetland complex is internationally important for migratory populations of Little Gull Larus minutus (up to 5,000 birds counted during one census), Caspian Tern (up to 200 birds), Little Tern (up to 500 birds) and of Black Tern (up to 7,000 birds).

Floodplains and mudflats of the delta and adjacent fishponds are the key stop-over sites for migratory populations of waders in Lithuania. Up to 11,000 staging Lapwings Vanellus vanellus, 8,000 Ruffs, 5,000 Dunlins and large staging aggregations of other species of waders were recorded in the site in recent years.

Internationally important concentrations of Great Cormorant Phalacrocorax carbo (up to 2,500 birds) were also registered in the site during the last years.

On 19 September 2007 internationally important concentrations of Great White Egret Egretta alba were recorded in the whole territory of the Nemunas River Delta Regional Park, with 1,050 birds counted. It was the first registration of so large concentration of Great White Egrets in the Baltic States. Great White Egret was a very rare species in the Baltic region during the 20^th century, while a very rapid increase in numbers of non-breeding birds was registered during the last 5 years due to the global climate change.

During warm winter the Nemunas (Neman) River delta supports up to 20,000 waterfowl. It is also the key wintering ground of White-tailed Eagle in the region, with up to 40 birds recorded in mild seasons.

Threats

Most natural seasonally flooded meadows of the site have been transformed into cultivated meadows since early 20^th century. Changes of the natural hydrological system have resulted in local drying of forest stands and changes in valuable plant communities. The lack of traditional cattle grazing and haymaking in the site has caused a rapid overgrowing of particularly valuable open floodplains with shrubs and young forests. Abandonment of large territories earlier used for traditional agriculture is a major threat to the local populations of very rare species of birds.

The extension and reconstruction of existing polders system can impact the hydrological regime in Lithuanian part of the site. The ongoing peat extraction is the main threat to Aukstumala raised bog complex.

A rapid increase of poorly regulated recreational load is a major threat to the most valuable habitats of the site. Important habitats (particularly banks of rivers and estuaries) are threatened by development of new recreation resorts, illegal campings, etc. Increased recreational activities including power boating, leisure boating and intensive recreational fishing are main sources of disturbance for nesting and staging waterbirds.