The rock art sites (in the Central Highlands of Tanzania) provide an invaluable historical record of the diverse economic and social activities of human communities and their intellectual, imaginative and emotional expressions over many millennia. This patrimony should be protected, preserved and illustrated. It should become a source of historical awareness, of culture and of education for the people of Tanzania, for Africa and for the World. Every effort should be made to save it for future generations. (UNESCO report 1980).
Ancient rock art is often found in areas where the art itself is not protected from involuntary and voluntary deterioration, yet there is ample evidence to show that with the implementation of relatively simple measures, most of the man-made deterioration can be stopped. In the case of the prehistoric rock art of Singida and the Lake Eyasi Basin, North Central Tanzania, the work of Fidelis Masao highlights the urgent need for conservation efforts.
The state of preservation of the majority of the sites in Singida, Iramba and the L. Eyasi Basin is generally poor. Equally bad conditions of preservation were also observed in the Kondoa area. M.D. Leakey remarked that even as far back as 1929, T.A.M. Nash had described the sites as being in a bad state of preservation. The sites are deteriorating so fast that unless the process is checked, most of the paintings will have completely disappeared by 2010.
Exposure to wind, rain, fluctuation of temperature, groundwater, seepage, biological growth and encrustation, all contribute to the deterioration of sites by the process known as weathering. Water and the organic acids secreted by lichen and other growths can slowly alter a sound and hard rock until it becomes chemically weathered. The building of concrete ledges to stop seepage or to increase the effectiveness of overhang, as in some Kondoa sites, has proved completely ineffective and in some cases accelerated the deterioration.
In central Tanzania, a number of the sites are also prone to strong winds for part of the year. As it blows, the wind picks up small grains of sand and pebbles that are hurled against the rock face, thus gradually contributing to the deterioration. In addition, the wind knocks off small flakes, which might otherwise have held on to the rock face for a longer time, finishing off the process started by the fluctuations of temperature.
Despite these numerous natural elements of deterioration, vandalism is by far the most pernicious threat to rock painting sites in Singida, Iramba and Mbulu. Visitors’ habit of writing names, initials, dates, slogans and all sorts of graffiti unfortunately seem to be on the increase. School children are perhaps the most notorious perpetrators. They use white and coloured chalk, charcoal, crayons and even industrial paint on the rock faces, causing serious damage to the paintings. Equally destructive, is the practice by some herders of using the rock shelter as a temporary kraal for their cattle. As the cattle rub against the painted rock panel, they accelerate the process of deterioration.
Of late, the worst culprits have been the cave robbers in search of German gold coins. Over the last few decades, some unscrupulous people spread the idea that the paintings were markings executed by the Germans during and after the First World War as identification symbols for shelters under which they had buried some treasure, supposedly including German coins and gold. The rumour spread so fast and extensively that almost every other painted rock shelter has now had its ground excavated, which has badly disturbed archaeological deposits. In their greed for immediate wealth, the culprits make big fires at the base of the shelters or use dynamite to crack and thus easily break the rock. Unfortunately there is still much evidence that this practice continues to this day.