Harmful species ‘invade’ Dar es Salaam

A man carries a Nile Perch of 80 kilograms in Kasinyi, Entebbe, Uganda.©AFP

TANZANIA has more than 120 invasive species whose impact can be harmful to the country's economy, the environment and human health.

Speaking exclusively to the 'Daily News', Ms Hulda Gideon, of Tanzania Commission for Science and Technology (COSTECH), described invasive species as those that are not native to the ecosystem. She said that the introduction of such species causes harm to the economy, environment and human health.

"They are characteristically adaptable, aggressive and have a high reproductive capacity.Their vigor combined with a lack of natural enemies often leads to population outbreaks," Ms Gideon explained.

A study and documentation of invasive species launched in 2010, showed that the country had 60 such species, but recent documentation of the invasive species shows that there are more than 120 at the moment. COSTECH, in collaboration with other research institutions and other stakeholders, agreed to establish the Tanzania Biodiversity Information Facility (TanBIF).

TanBIF is a platform for sharing data and Information on biodiversity to reduce duplications and it is made up of a consortium of national institutions dealing with biodiversity. Currently it has 35 members, Ms Gideon, who is also the manager of TanBIF noted.

TanBIF is a member of Global Biodiversity Information Facility (GBIF) whose head offices are in Copenhagen, Denmark. This makes it easy for TanBIF to access and repatriate data that is outside the country, according to Ms Gideon.

"Apart from documenting them, the other reason is that authorities will know where they are and take measures to control them," she said.

She revealed that COSTECH is soon embarking on niche modelling of the invasive species, using data already collected by researchers to know where the species are and environments they are likely to thrive on. Invasive species, she noted, are considered to be one of the top causes of biodiversity loss worldwide.

She cited the introduction of the Nile Perch (Lates Niloticus) in Lake Victoria in the 1960s, leading to disappearance of about 200 native fish species from the lake.

"Invasive species can transform the structure and composition of the ecosystem by repressing either directly by competing with them for resources or indirectly by changing the way nutrients are cycled through the system," she explained.

Ms Gideon added that the global domination by few invasive species threatens the creation of a homogeneous world rather than a world characterized by greater biological diversity and local distinctiveness.

"The black house crow, has established itself in 25 countries worldwide, proliferating in human settlements and disturbing habitats. It causes chaos in Dar e Salaam, Morogoro and Zanzibar," she explained.

Foliage and seeds of Leucaena leucocephala contains amino acids called mimosine, which poisons other plants and could be one of the reasons, why the plant has colonized riverbanks, roadsides and cultivated land in Dar es Salaam. Other invasive species include Pathernium, which is a form of weed that is destructive and spreads quickly.

It threatens agriculture, wildlife and human health especially for people with allergies. It is found in Arusha, Ngorongoro and Serengeti National Parks. The quava tree, which bears fruits and is found in most regions in the country, are also invasive species from Mexico, "nothing grows underneath the quava tree," Ms Gideon.

By ROSE ATHUMANI

Source @Daily News