Tuesday

No respite as weed chokes Nairobi Dam

By NAFTALI MWAURA

The hyacinth weed has literally choked Nairobi Dam. The highly noxious weed that invaded this Dam close to six years ago has formed a carpet hence reducing a once valuable ecological resource in the Capital city to total waste.
Nairobi Dam is an eyesore due to hyacinth weed that has held a vicious grip to a Dam that once gave this City picturesque landscape for residents to savour and relish with abandon.
The weed forms a green carpet over Nairobi Dam and has obliterated its face. According to a resident who has lived near the Dam for the last twenty years, a Mr Joseph Ngigi, the Dam used to be a valuable resource to Nairobians who sampled its many benefits like providing water for domestic use and irrigation, recreation and fishing.
The Dam is strategically sandwiched between a number of both upmarket and poor neighbourhoods located in the south of the Capital.
Nairobi Estates adjacent to the Dam are Kibera High rise, Ngei Estate, Madaraka and the sprawling Kibera slums.
People residing in these estates according to Mr Ngigi used to visit the Dam for recreation activities like scuba dive, boat racing and swimming. The Dam had been a source of water for various Agricultural practices. According to Ngigi, urban farming that thrived in the 1980`s and early 90`s is wholly attributed to the Dam. People living in the vicinity have always engaged in intensive farming activities around the Dam.
The Dam has provided water for cultivation of vegetables, maize, potatoes, and sugarcane. Infact Nairobi at one time boasted of large harvest of food crops like the rural highlands. A leisure walk along the shores of the Dam were an uplifting expedition to City residents who cried for an air of relief after spending six days of depressing helter skelter in search for a living.
Mr Ngigi and his generation can only ponder with nostalgic collections on the halcyon days when the Dam was so clean and being a haven of tranquillity it was, they used to visit the Dam for picnics and Dates with youthful lovers.
Not any more.
The Dam is today a complete shell of its former shelf. It has been polluted heavily and emits pungent but choking smell. An Environmentalist working for a reputable consultancy firm dealing Environmental matters, Mr Leo Fernandez explains that the uncontrolled discharge of effluent into the Dam provided ideal conditions for the Hyacinth to blossom in the Dam. There is a lot of waste material being drained into the dam. The bulk of this waste originates from factories and residential estates in the vicinity. The proliferation of unplanned settlements whose hallmark is overcrowding, poor sanitation and haphazard waste disposal has also aggravated the situation. Slums and illegal settlements are a source of most of waste material discharged into the dam.

The hyacinth weed originated from Latin America. It is highly noxious. It spreads so fast and chokes inland water bodies leading to immense ecological and economic losses. The weed has invaded Lakes Victoria, Naivasha and the Nairobi Dam. The weed is non-native, is endowed with unique characteristics such as lack of predators, ability to take nutrients, hardy seeds that can last for ten years. These unique features enable the weed to survive in the water all seasons round, according to Environment lecturer in Daystar University, Mr. Peter Ngure.

Domestic and industrial effluent that is drained into the dam provides nutrients that enable the weed to blossom. Though the weed can be useful in making furniture and composed manure its threats to our lake ecosystems and other biodiversity far outweighs any benefit.

There have been concerted efforts of late geared towards eradication of hyacinth weed at the Nairobi Dam. The World Bank and Nation media group have come together to seek ways of removing this toxic weed from Nairobi Dam. The two organizations have earmarked 400 million Kenya Shillings to fight the weed. The cost involved is quite astronomical and calls for wider participation of stakeholders.

Campaigns to save Nairobi Dam are at fever pitch, according to a Nairobi City Council officer. Residents who have relished in its many benefits of yester year have united to press the case for its reclamation. They have gone ahead to raise a fund, have lobbied corporate bodies, the Government and donors to make a tangible commitment in terms of resources that can help in saving the dam from the hyacinth grip.

So far scientists are grappling on how to go about eradicating hyacinth from Nairobi Dam. The case to fight this noxious weed using either biological or chemical means is yet to be resolved amicably. Despite this stalemate from the scientific community, Nairobi residents like Mr. Ngige who are passionately committed to efforts to save the dam are yet to give up and wish that more people would open their eyes to see the ugly face of a once beautiful dam and help realise its restoration

1 comment:

Anonymous said...

Hello

My name is Richard Arao, and I am a recent B.Sc. Biology graduate.
For the past one year I have been conducting independent research on
phytoremediation using waterhyacinth and what I have come up with so far is a literature review highlighting the benefits as well as manner in which hyacinth has been used in some regions of the world.

The gist of my 30 page paper is an integrated approach towards using
Water hyacinth for large scale waste water treatment, and from there using the accrued biomass for its multiple beneficial products ranging from compost and biogas production, paper/mat/furniture production, to
building materials, beneficial root extracts and diet Supplements. Most of all, it is quite a good avenue for job creation.

In Kenya, understandably, scientists tend to be wary about using hyacinth because of the documented effects that it has had in places like the Lake Victoria Basin. And even though, so far, the hyacinth provides a raw material for some small scale cottage industries, antagonists
argue that the cottage industry does not harvest the weed fast enough to act as a check to its growth and proliferation. However, I am of the impression that there are far more uses for the weed’s biomass than just the cottage industry. In my research I have come across various uses for
the weed, like incineration and gasification of the weed, which yields Potassium Chloride and Ammonium Sulphate respectively; as a fodder supplement, whereby, research with goats showed that the hyacinth could beneficially constitute as much as 40% of the goats’ diet. Similarly, its roots also contain growth promoting compounds (cytokinins) which upon being extracted have been shown to increase rice yields to a greater extent than Gibberellic Acid.

Very recently, bioinorganic chemistry is being used to Extract, purify and characterize both Phytochelatins and Metallothioneins, cysteine-rich peptides that have been shown to be responsible for the hyacinth’s
ability to sequester heavy metals like Lead, Cadmium, Zinc, Chromium
and Copper from its aquatic habitat. There is also the fact that carotenes can be extracted from the hyacinth leaves, thus providing a necessary dietary supplement that could help to prevent a lot of cases of Blindness among Kenya’s poor whose diets do not afford them the necessary amount of vitamin A. Also, research has shown that some plant-root extracts are ideal sources of natural nematicides, which are safer to use than synthetic nematicides and have less chance of finding their way into the food chain, and it would be worth a try to carry out research to determine whether hyacinth roots might have a similar beneficial effect.

And finally it can be used as black pigment for paints and ink by the process of pyrolysis, and, in the newest scheme of biochemistry, I believe its roots might be able to be used to conduct “green chemistry”.
Lab experiments with carrots (Daucus carota) have shown that they can be successfully used to reductively yield enantioselective products, but the problem with this type of work is that carrots are actually edible roots. If Hyacinth root could be used in the same way, since they are inedible, and quite plentiful, I believe this would augur well for industry, as well as the environment as a whole.

With all these uses potentially capable of producing economically
viable products, I think that possibly this would be an incentive for more and more people to harvest the weed, as opposed to before when most of the biomass just yielded waste destined for a landfill. What I would first like to do is to get my paper published, and I would like to know whether your organization has an in-house peer-reviewed magazine to which I could submit my paper for publishing. After that I would like to present the paper to KIRDI (Kenya Industrial Research & Development Institute) because I believe they have the means and resources to carry out the R&D needed.

The environment weighs heavy on many people’s mind these days, and my main concern is the quality of water that the average Kenyan is exposed to. That’s why I undertook the research. Honestly, it also ties in the issue of sustainable development because I believe it can create a myriad of jobs based principally on environmental conservation.


CONTACTS:
Richard Arao
P.O. Box 58736-00200
Nairobi, Kenya.
Tel: (254)-045-40868 or (254)-(0727)-989352
Email: Richardona@Yahoo.com or Richardona@gmail.com

google pagerank checker by smallseotools.com