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April, 2015 News

VRA Allays Fears of Riverine Communities in the Lower Volta Basin to Control Growth of Water Hyacinth

The Environment and Sustainable Development Department (E&SDD) of the Volta River Authority (VRA) is to intensify its efforts at eradicating water hyacinth from the Volta Lake through the application of a chemical known as glyphosate. The water hyacinth plant when cleared on the Volta Lake would help the Authority not only preserve its water bodies but also save water in the lake.

Speaking at series of consultative meetings held in Municipal/District Assemblies and communities within the Lower Volta area to solicit views on the use of the glyphosate chemical in fighting water hyacinth, a Principal Officer at the Public Health Section of the Environment and Sustainable Development Department of the Volta River Authority Mr. Michael Dade noted that the Authority is greatly worried about the increasing level of water hyacinth on the Volta Lake hence the need to bring it under control.

He said the control of water weeds in the Volta Lake has been an on-going activity since the impoundment of the Volta River at Akosombo and Kpong in 1965 and 1982 respectively; however, it is not until 1998, when the menace of weeds appeared to have worsened following the invasion of the Lake by Water hyacinth.

Mr. Dade disclosed that it has been observed over the years that removal of these weeds manually as well as the biological control through the use of bio-agents had been slow especially where weed cover was extensive and not easily accessible. In such instances, the rate of control was outpaced by the high rate of proliferation. It is in this regard that the option of applying herbicides for its rapid control particularly in areas that cannot be easily accessed through manual control is being considered.

He assured the Municipal/District Assemblies and the communities that the use of glyphosate is known to have none or minimal effects on human or fishes due to different biochemical pathways observed in plants and animals in protein synthesis.

What Water Hyacinth is
Water hyacinth is a free-floating perennial aquatic plant (or hydrophyte) native to tropical and sub-tropical South America. With broad, thick, glossy, ovate leaves, water hyacinth may rise above the surface of the water as much as 1 meter in height. The leaves are 10–20 cm across, and float above the water surface. They have long, spongy and bulbous stalks.

In the United States of America, the water hyacinth was introduced in 1884 at the World's Fair in New Orleans, also known as the World Cotton Centennial. The plants had been given away as a gift by a group of visiting Japanese. Soon after, the water hyacinth was choking rivers, killing fish and stopping shipping in Louisiana, and an estimated 50 kilograms per square meter choked Florida's waterways. There were many attempts to eradicate the flower, including one by the U.S Water Department to pour oil over many of the flowers, but none worked.

While in Africa, The water hyacinth appeared to the north in Ethiopia, where it was first reported in 1965 at the Koka Reservoir and in the Awash River, where the Ethiopian Electric Light and Power Authority has managed to bring it under moderate control at the considerable cost of human labor.

In Rwanda it was introduced by Belgian colonists to beautify their holdings and then advanced by natural means to Lake Victoria where it was first sighted in 1988.There, without any natural enemies, it has become an ecological plague, suffocating the lake, diminishing the fish reservoir, and hurting the local economies.

Water Hyacinth on the Volta Lake
Mr. Dade addressing one of the consultative meetings disclosed that water hyacinth was first reported on the Volta Lake in 1998 on River Oti, then 2003 and 2006 in the Kpong Headpond and Lower Volta respectively.

According to him the plant grow very fast with the ability to double its population within two weeks under suitable environmental conditions.

"The invasion of water bodies by water hyacinth has become a nuisance worldwide. For us in VRA, the presence of water hyacinth in the Volta Lake particularly the Oti arm, the Kpong Head pond and the Lower Volta segments has effects on efforts at managing the Kpong Head pond reservoir for power generation, protecting the Lake environment as well as safeguarding the health and well-being of the Lakeside dwellers," he noted.

The Danger Water Hyacinth Poses
Speaking on the dangers and control of water hyacinth on the Volta Lake, an Environmental Officer of the Authority with the Environment and Sustainable Development Department (E&SDD) Mr Andreas Andoh said when not controlled, water hyacinth has the capacity to cover lakes and ponds entirely.

The above he believes can dramatically impact water flow, blocks sunlight from reaching native aquatic plants, and starves the water of oxygen, often killing fish (or turtles).

He indicated that water hyacinth also create a prime habitat for mosquitos the classic vectors of disease, and species of snail known to host a parasitic flatworm which causes schistosomiasis (snail fever).

"Water hyacinth is often problematic in man-made ponds if uncontrolled, but can also provide a food source for goldfish, keep water clean and help to provide oxygen to man-made ponds. It is often invades bodies of water that have been impacted by human activities For example; the plants can unbalance natural lifecycles in artificial reservoirs or in lakes that receive large amounts of nutrients," he said.

Chemical Control
Mr Andoh observed that there are three commonly used control efforts to suppress water hyacinth infestations. They are physical, chemical, and biological controls.

However, he noted that no one control is better than the other because each has its advantages and disadvantages. The choice of control is dependent on the specific conditions of each affected location such as the extent of water hyacinth infestation, regional climate, and proximity to human and wildlife.

He said the Authority would be employing the use of a chemical known as glyphosate to help eradicate the water hyacinth on the lake.

"The application of glyphosate for the control of water hyacinth in the Lower Volta is expected to reduce the intensity of infestation of water hyacinth and restore the ecosystem value of the Volta River in the Lower Volta Basin," he noted.

Community leaders of some impacted communities and officials of Volta River Authority pose for the camera.

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