The largest lake in Africa
Lake Victoria: a sick giant
Lake Victoria was discovered in 1858 British Explorer John Speke, after a few months of their research, the sources of the Nile. Then the lake appeared in front of him so large and beautiful that he gave him the name of the British Queen. But now the Lake is in poor condition and is on the brink of environmental disaster. If John Speke could see lake Victoria today, painting what he saw would have caused him most likely shock and disbelief. The lake has become a smelly, suffocating from algae, a large body of water.
Ecological health of lake Victoria has been deeply undermined by the rapidly growing population, boom in fish exports, the disappearance of some fish species, the rapid growth of algae and the discharge of untreated sewage by industrial enterprises. Most of the damage is extensive and irreversible. The traditional way of life of the lake communities almost destroyed. Scientists are concerned that soon the lake Victoria may become dead.
Named in honor of the Queen of England, the African lake Victoria is the world’s largest tropical lake and second largest freshwater lake. The area of the lake on a total of 69 000 square kilometers. Although this region of Africa is better known for its large cats and the herds of wildebeests, zebras and giraffes that roam the Savannah, however, its most diverse and endangered ecosystems are under water.
At the beginning of the 20th century, several decades after the opening of Spica, the colonialists started to exploit lake Victoria. They cleared the surrounding area from natural vegetation, destroying the forest. On the released areas were planted with economically favorable, or more correctly, cash crops such as tea, coffee and sugar. For many years, plantations of cash crops has grown in size and number. Agricultural chemicals, applied on these plantations drain into the river during the rainy season, and eventually fall into the lake, providing a favorable nutrient medium for the growth and bloom of algae.
To work on the plantations attracted migrant workers, resulting in an increasing population of the coastal areas. Another problem was the excessive catch of fish. By 1950 the catch of the traditional Lakers has increased so much that some species are almost extinct.
To remedy the situation, British officials attempted to introduce into the pond with new fish species: the Nile tilapia (Oreochromis Niloticus) and Nile perch (Lates Niloticus). New species of fish made up only a small proportion of the fish biomass of the lake, while the cichlids (small indigenous species) accounted for 80 percent. Until the late 1970-ies, the composition of the biomass of the lake has remained relatively constant, but in recent lake survey showed a sharp and unexpected change. The number of cichlid species fell sharply and amounted to only 1 percent of the total weight of fish in the pond, while the percentage of Nile perch had jumped up and was 80 percent.
Cichlids – species of small bony fishes that require water saturated with oxygen. But the waters of the lake are depleted, lacking oxygen, become unsuitable for many fish. There are serious concerns that soon the lake becomes a dead zone. A significant role in the disappearance of the cichlids played and the voracity of Nile perch.
Although the lake for many years was applied irreparable harm, scientists around the world are now taking measures to not let the huge lake to die.