Local and international scientists are assessing the natural habitat of the rare Kihansi spray toads (KST) in the Kihansi gorge in south-central Tanzania to establish whether a fungal disease that almost wiped out the rare amphibians in 2003 is still in existence.
Experiments of the fungus called chytrid that led to a sudden decline of the toads are part of efforts toward translocation of the KST from the United States.
In 2000, 500 KST were translocated to the US with the hope of propagating stable captive assurance colonies and they were divided among several zoos, including two institutions where they remain today— the Toledo Zoo in Ohio and the Bronx Zoo in New York.
The population size of the rare toad in the US zoos has been rising since 2005, and today, its populations are limited to the two remaining captive zoos, currently totalling about 6,000 individuals.
Dr Charles Msuya, an amphibian ecologist and laboratory scientist with the University of Dar es Salaam, said yesterday the scientific experiments will lead to the translocation of 1,000 KST from the US to Kihansi gorge in March, next year.
“We want to assure the scientific world that the place is safe for the translocation of the rare toads,” he said in a telephone interview, adding that Tanzanian scientists have teamed up with their colleagues from South Africa and elsewhere conducting the experiments.
Dr Msuya added that the experiments were being done in laboratories at the Sokoine University of Agriculture in Morogoro, the University of Dar es Salaam and in South Africa.
“We haven’t detected any fungal disease that could be harmful to the amphibians until now, and we hopefully plan to finish this task in January, next year,” said the amphibian ecologist.
Asked on the progress of the first batch of 100 KST who were translocated from the United States in August to Tanzania for trail and testing of a captive facility at the University of Dar es Salaam, Dr Msuya said they have produced over 150 live offspring.
He said about 30 out of the 100 adult KST have been used in experiments, adding a census for the newly born offspring will be done in a few weeks’ time.
The Kihansi spray toad, scientifically known as Nectophrynoides asperginis, appears to be one such species on the brink of extinction.
Endemic to 2.0 hectares of spray zone in the Kihansi gorge, its natural habitat was decimated by hydro power dam construction from 1996-2000 and the outbreak of an amphibian fungus called chytrid in 2003.
The $275million (about Sh385billion) 180-megawatt hydroelectric facility is operated by the Tanzania Electric Supply Company (Tanesco) and was financed by the government of Tanzania, the World Bank, the Norwegian Agency for International Development (Norad), the Swedish International Development Agency (Sida), the German development bank (KfW) and the European Investment Bank (EIB).
The World Bank had approved a total of $10million (about Sh14billion) International Development Association (IDA) credit for the long-term conservation of the Kihansi gorge ecosystem and upstream catchment areas, including the protection of the toads.