Ohrid is a natural and artistic treasure among mountains and shores of Lake Ohrid in the western part of the Republic of Macedonia. Ohrid has preserved its core in the old part of the city on the double hill of the Samuel Fortress. Within the limits of the medieval borders a number of archaeology and art lovers would discover more that they expected. Those who happen to be introduced to Ohrid would come back to enjoy the city – museum, whose single church, fresco or icon become invaluable rarity. The visitors take back a specific atmosphere of the tranquillity that exists of the narrow and steep streets filled with beautiful buildings from the old city architecture and with medieval temples with picturesque facades as a decor of the blue Lake Ohrid the oldest one in Europe and one of the most beautiful lakes in the world. On the 5th of September 1980 the City and the Lake of Ohrid were declared a cultural and natural heritage site under protection of UNESCO. Situated in the southwest of Macedonia on the border with Albania, in the Ohrid valley, surrounded with high mountains, with its deep blue waters, Lake Ohrid represents an extraordinary natural beauty which has great economic value for the region and tremendous scientific significance for the World. This “Blue Pearl” has attracted people for a long time ago for various reasons; to settle in the vicinities and using its natural sources, tourists have enjoyed its beauty as well as the surrounding. Challenging scientists from all over the world have revealed some of the lake’s endless secrets.
Due to its tectonic origin, in the distant geological epochs (4-10 million years ago), the geographical isolation of this lake from the rest of existing fresh waters of that time, the great water volume (53 km3), and the permanent life conditions till today, this lake has become a sanctuary for many organisms from the tertiary period, which from other hand, earns another epithet to the lake – a museum of “living fossils”. The lake itself has very transparent waters with maximum transparency of 22 m in winter. This is a result to its oligotrophic state (low production of organic matter) and respectively to that relatively low fish yield.
Inhabited by a tremendous sets of unique creatures that can be nowhere else found in the world, induced with the favourable life conditions, the lake has become one of those several lakes in the world where future evolution took part among its inhabitants in terms of forming new subspecies, species, genera and even families. The relatively huge endemism – more than 200 endemic species – is mainly expressed among the creatures living at the lake bottom. The endemism that is also expressed among the fish fauna with 60% from the 17 native fish species is another rarity. Some of the endemic inhabitants of the lake, especially the round shaped sponge Ohridospongia rotunda represents a certain evidence that Lake Ohrid, unlike most of the lakes of the world has never been dried out since its formation.
These facts, from the end of 19th century till nowadays attracts various scientists from the world (geologists, biologists, hydrologists, palaeontologists, physicists etc.) to work on this lake and the secrets they have solved has great contribution to the general knowledge of lake’s and organism’s evolution on the Earth. This high scientific value of Lake Ohrid, in the year 1935 led to establishment of a permanent research centre on the shores of the lake – The Hydrobiological Institute. This institute also has hatchery facilities for breeding the endemic dominant and economically the most important fish from the lake – Ohrid trout for stocking purposes. Since 1935 till today the lake has been stocked with over 800 million of Ohrid trout offspring. Besides the Ohrid trout another endemic trout species increases more the value of the lake and its high quality fish fauna – the Ohrid belvica. At present both of them are highly endangered species.
Another fish, the Ohrid bleak that is the most numerous in the lake, has been used in former times for manufacturing the famous “Ohrid pearl”. This souvenir has fascinated a number of visitors to this region, increasing the glance and glamour of women around the Globe. In the world today exist just a few other lakes, with similar age, origin and a high percentage of endemism. These lakes include, lakes Baikal, Titikaka, Victoria, Malawi. The Macedonian freshwater see – Lake Ohrid – has also significant tourist, fishery and other economic importance. The microclimatic conditions mainly caused by the lake are giving to the region conditions of favourable medical resort. The very clean waters of the lake are making it one of the largest drinking water reservoirs in the world.
Hydrobiological Institute – Ohrid