ENVIRONMENT

Tallinn is situated in an area of highly variable landscape. A high terrace of limestone runs through the whole city and descends to long sandy peninsulas and beaches. The coastal waters of the city of Tallinn cover the area between the Kakumäe and Viimsi peninsulas. There are three distinct bay areas: Tallinn Bay, Paljassaare Bay and Kopli Bay. The shorewaters are shallow, but deepen rapidly. Tallinn Bay has a steep slope, which allows for good water exchange with the waters of the Gulf of Finland. Tallinn Bay is 20-45 metres deep. From Paljassaar Peninsula and Viimsi Peninsula a shallow underwater plain continues towards the north. The salinity of surface water is 5-6 per mill, as there is no major river in the region, only small rivers, such as the Pirita, bring fresh water into the sea. There are two islands, Aegna and Naissaar, and two bigger lakes: Harku (160 ha) and ülemiste (992 ha), the latter of which is the main raw water source.

Lake Ülemiste:
Total volume	34.8 million m³
Average depth	2.5 m
Maximum depth	4.2 m
Height from the sea level	35.7 m

The Old Town is situated close to the sheltered Tallinn bay, which is a natural harbour and the main passenger port. The harbour in Kopli Bay serves mainly for cargo traffic. There are three public beaches: Pirita, Stroomi and Kakumäe on the coastline.

Research history

The history of scientific studies concerning Tallinn's sea area has not been studied, yet several studies were accomplished on the flora and fauna of the area already in the 19th century.

The first studies on the bottom vegetation of Tallinn Bay were made already in the mid19th century:

Eichwald, E. 1849: Zweiter Nachtrag zur Infusorienkunde Russlands. Bull. Soc. Imp. Naturalistes Moscow 22(2): 400-548.

In the 1870s several publications by Russian scientist C. Gobi provide desciptions of the flora of Tallinn Bay.

Gobi, Chr. 1874: Die Brauntange (Phaeosporeae und Fucaceae) des Finnischen Meeresbusens. Mem. Acad. Sci. St. Petersburg. 7 Ser. 21(9): 1-21.
Gobi, Chr. 1877a: Über einige Phaeosporeen der Ostsee und des finnischen Meerbusens. Bot. Zeitung (Leipzig) 35: 526-547.
Gobi, Chr. 1877b: Die Rothtange (Floridaea) des finnischen Meerbusens. Mem. Acad. Sci. St. Petersb. 7 Ser. 24(7): 1-7.
Gobi, Hr. 1875: Zametka o vodoroslah Finskovo Zaliva. -Tr. CPB. Obs. Estestv. T 6:17-21.
Gobi, Hr. 1879: Otzot ob algologizeskih isoskaniah, proizvedennoh letom 1877 g. v. Finskom zalive. Tr. CPB Obs. Estestv. T 10: 83-92.

In the 1930s the macrophyte vegetation of the Estonian coastal area was studied by Finnish scientist Ernst Häyrén:

Häyrén, E. 1931 Einige Flechtenfunde aus Estland. Memoranda Soc. Fauna Flora Fennica 6: 122-128.
Häyrén, E. 1931 Einige Algenfunde an den Meeresküsten Estlands. Memoranda Soc. Fauna Flora Fennica 6: 174-179.

Pollution problems

As soon as at the beginning of the 20th century increasing sewage loads caused local, mainly hygienic problems. In the 1930s the paper and pulp industry polluted the central bays, and at times the public beaches were closed to swimming. It is not known if these conditions were studied.

During recent decades several studies of the state of the Tallinn Bay area have been made by local authorities, the Estonian Marine Institute and Tallinn Technical University. At present no recipient monitoring is being done. The most polluted areas are concentrated around the harbour of Tallinn, which receives effluents from passenger ships, sewage overflows and storm water discharges. The remaining coastal parts are only slightly polluted.