Characteristic of the seacoasts

• Beaches
• Primary dunes
• Foredunes
• Grey dunes
• Dunes slacks
• Bluffs
• Wetlands
• Flora
• Fauna

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Beaches commonly are formed by easily washed out sediments (sand, gravel and pebble) and are directly submerged to regular sea and wind influence. Walking along the water line from Nida to Ainaži, we can observe sandy, stony, pebble and gravel beaches. Their width varies from 5-10 to 50-100 meters and even more. Most widespread are sandy beaches where in comparison with the other beaches higher species and habitat diversity is observed. Most characteristic plant species are Cakile baltica, Salsola kali and Honckenya peploides. These plants commonly grow scattered or in small groups. Most of plant species grow on low wet beaches where annual plants dominate, like Chenopodium sp. and Atriplex sp. Well developed beach communities are in August and September when the species composition has stabilised; spotted or in some places continuous plant cover is observed. Differently develop habitats in stony beaches where perennial vascular plants dominate (Laime 2000).

Beach
Photo: B.Laime

Dunes are wind flown sandy ridges. Near the sea both open dunes and those covered by trees and shrubs occur. In open dunes two zones are distinguished - primary dunes and grey dunes. Primary dunes are located most close to the sea and commonly border with the beach and where sand flooding takes place. Primary dunes are characteristic only in those sections of coast where sand accumulation takes place. Total length of primary dunes in Latvia is about 240 km (Anon. 1993). Development of primary dunes starts from embryonic dunes that are small up to 50-cm high sandy formations with scarce vegetation. Characteristic species are Leymus arenarius, xCalammophila baltica, Honckenya peploides and Elytrigia x littorea. With the continuation of sand accumulation and plant cover development these primary dunes develop into foredunes. Their medium height is 1-3 m

Dunes
Photo: B.Laime

although 5-6 m or even higher occur. Mainly there are coastal sections where is only one foredune, in medium 50 m wide.In places where sand accumulation processes are more active 2 or 3 foredunes develop that can be 100 and more meter wide. Grasses dominate on foredunes, the most common are Ammophila arenaria, Calamagrostis epigeios, Leymus arenarius and Festuca arenaria. In Latvia foredunes with shrubs are characteristic, mainly with willows, like Salix viminalis and Salix daphnoides. They are planted to stabilise dunes or have arrived on their own.

On beaches and primary dunes 282 plant species grow (Laime 2000). Data obtained from the studies of the botanists of the University of Latvia, Faculty of Biology from 1989 to 2002. Many species are weeds, garden escapers and invasive plants. Comparing the flora of beaches and primary dunes in different sections of the coast it was found out that more rich is the coast of the Gulf of Rīga, especially between Rīga and Kolka. Near the Gulf of Rīga 240 species occur, on the coast near the Baltic Sea from Nida to Kolka 113 species. It can be due to the diversity of coastal habitats and it concerns mainly Kurzeme part of the Gulf of Rīga.

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A grey dune is a secondary type of dunes that develops from primary dunes. Grey dunes are relatively stable. Bryophytes, lichens and low vascular plants as well as separate trees and shrubs form the plant cover. On grey dunes in Latvia 163 species of Pteridophyta and Spermatophyta grow, 30 bryophyte species and 44 lichen species from which 23 are Latvian Red Data Book species (Laime, Rove 2001). Special attention must be paid to those species whose habitats are mainly connected with grey dunes and which have a small distribution area, like Dianthus arenarius subsp. arenarius.
Grey dunes in Latvia are a rare and specially protected habitat (Anon. 2001) and are distributed unevenly, mainly near the coast of the Baltic Sea. Width of grey dunes varies from several metres up to 30-50 metres. Near the coast of the Gulf of Rīga the medium width of grey dunes is 5 metres. Near the coast of the Baltic Sea it is between 5 to 10 metres. Grey dunes are found in Užava (width up to 50 metres) and in the north of Pāvilosta (width about 100 metres).

Grey dunes
Photo: B.Laime

Bluffs
Photo: B.Laime

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Wetlands
Photo: B.Laime

Flora
Typical plant species on beaches and primary dunes

Characteristic species of grey dunes

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Fauna
Seacoast habitats are important habitats for feeding and migration of many animal species. In the coastal zone at least half of the Red Data Book bird species appear, like Tadorna tadorna, Haemotopus ostralegus, Pluvialis apricaria, Calidris alpina schinzii etc. Most of them are registered during migration (Ādamsons 1986, Lipsbergs 1985, Pēterhofs 1984). It concerns also bats. During autumn migration, for example in Pape ornithological station all 15-bat species found in Latvia were observed (Pētersons 1997). Sandy beaches and foredunes are considered as a typical habitat for Bufo calamita. Up to know several isolated populations are observed at the seacoast (Bērziņs 1984, 1987, 1988). At the seacoast, especially in places washed by seawater quite high insect diversity is observed. Several rare species appear there, like Laphria gibbosa, Laphria flava and Cicindela maritima.

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