Ghana’s effort towards controlling water hyacinth: An Example for Nigeria?
by DEPO Adenle
In a recent CNN’s recent programme on profiting from pulling nasty weeds it was revealed that aquatic hyacinth is overtaking Africa’s Lake Victoria, but entrepreneurs are using the invasive weed to create baskets and rope to sell. The Kenyan authority who spoke on the programme was not convinced about the effectiveness of the entrepreneurs’ approach to curbing the exploding rate at which Lake Victoria is being prevented from serving its useful purpose.
It adversely affects the biodiversity and functioning of wetland and riparian ecosystems, water quality, water storage and distribution infrastructure, recreation and amenity values. It is often described as one of the worlds’ worst aquatic weeds.
Water hyacinth can be controlled using three methods (Wikipedia):
The application of herbicides for controlling water hyacinth has been carried out for many years and it has been found that there is a good success rate when dealing with small infestations. A main concern when using herbicides is the environmental and health related effects, especially where people collect water for drinking and washing.
Physical control is performed by land based machines such as bucket cranes, draglines, or boorm or by water based machinery such as aquatic weed harvester, dredges, or vegetation shredders. Mechanical removal is seen as the best short-term solution to the proliferation of the plant. It is however costly and requires the use of both land and water vehicles.
As chemical and mechanical removal is often too expensive and ineffective, researchers have turned to biological control agents (weevils) to deal with water hyacinth. Although meeting with limited success, the weevils have since been released in more than 20 other countries. However, the most effective control method remains the control of excessive nutrients and prevention of the spread of this species.
In the article below the Ghana EPA has opted for the physical control which is seen as the best short term solution. The seeds are believed to be able to grow even after about 3 decades. Therefore a site cannot be considered free of its regeneration until over 30 years.
What type of control should Nigeria adopt depends on whether it wants a short term solution or a long-term one, the latter requires development of a strategic framework to contain this invasive nasty weed. This blogger has witnessed how the physical control method failed at Ibadan in Western Nigeria, near the Government Secretariat, where it took less than a year for the complete regeneration and total coverage of the lake surface.
EPA Fights Water Weeds
By Emelia Ennin Abbey, Daily Guide Newspaper, Ghana
Published on November 26, 2012
Mrs Shirley Ayitey popping a champagne to commission the weed harvesters and transport badge while Mrs S. Amlalo looks on.
The invasion of aquatic weeds in the lower Volta which is threatening the livelihood of fishing communities will soon become a thing of the past following the commissioning of two harvesters and transport badges valued at $2.588,000.
The move, which falls under the integrated management of invasive Aquatic Weeds Project, saw the procurement of the facilities by the Environmental Protection Agency which, through the Ministry of Environment, Science and Technology, secured financing from the African Development Bank to control water weeds in the Tano and Volta Rivers.
The two weed harvesters which are like water mowers which would cut the vegetation are christened, Animati and Pediato after two traditional leaders in the lower Volta Area who championed the removal of the aquatic weeds, and the transport badges would be known as Yaakwabia and Manyaklo taking their names after the first female executive secretary of the then Environmental Protection Council and the people of the area respectively.
Daniel Amlalo, Acting Director of the Environmental Protection Agency, noted that the struggle with the invasion of water weeds started in the past two decades and as at 2006 about 6,066 hectares of the Lower Volta, Kpong Head Pond, the Oti and Tano Rivers and Lagoon Complex were covered with the weeds.
The infestations of the water weeds “have severely compromised the use of these water bodies by obstructing water supply, river transport, fishing, threatening hydropower generation and also increasing the prevalence of water-borne diseases such as Bilharzia.”
Until the acquisition of the weed harvesters, measures used in controlling the weeds which had been growing at a high rate had mostly been through removing the weeds by hand but that had not helped to control the phenomenon.
A 2009 survey by the EPA estimated that between 15 and 40 percent of open water surface of most reservoirs were infested.
Shirley Ayittey, Minister of Environment, Science and Technology, before cutting a tape and joining dignitaries to pop champagne to commission the weed harvesters and transport badges, stated that the invasive plants and weed species had been attacking the quality of life of the various societies and communities on a daily basis.
“It is government’s desire to transform the water weed menace into an opportunity for enhancing livelihood and income generation.
She disclosed that the EPA had trained communities to compost harvested weeds for crop production, “we will expand the initiative and create the value chain that will attract investment to transform harvested weeds into compost to boost agriculture.”
Mrs Marie-Laure Akin –Olugbade, Resident Representattive of the African Development Bank in Ghana, explained that the Bank supported Ghana with a concessionary loan of $2,588,000 and a grant component of $323, 500 under a five-year project to enhance aquatic weed removal.
With the mechanical harvesting, she said, it was expected that the critical mass of weed infestation would be reduced.
“It is expected that the Government of Ghana will continue to support and strengthen the achievements made through this project by expanding the scale of harvesting of the invasive aquatic weeds while ensuring that the harvested areas are not re-infested.”
The Volta River Authority (VRA) is expected to manage the Weed harvesters and the transport badges and Mr Kweku Awotwe, Chief Executive officer of the VRA, in a speech read on his behalf, gave the assurance that his outfit would operate and maintain the harvesters in a professional and responsible manner so as to make optimum use of the equipment.