Title : The Volta Lake: Aquaculture and Flooding
Abstract:
OVERVIEW: Aquaculture is the rearing of fish or aquatic species under controlled conditions for purposes of food, recreation, business, research, etc. It is one of the surest ways for fish production for the food industry. In Ghana and many parts of the world, aquaculture supports the National Economy through the provision of cheaper source of animal protein, job creation, poverty reduction and foreign exchange earnings. Traditionally, aquaculture is practised in earthen ponds, concrete tanks, tarpaulin tanks, cages and pens. Cages are known to be installed on large water bodies of appreciable depths and it ranges from the simple twin 5m x 5m x 3m room cages sizes to the highly commercial high intensity round cages mostly originated for the Scandinavian zones. THE VOLTA LAKE: the volta lake is considered the largest man-made lake in the world. It was formed out of the establishment of a hydro-dam at the southern end of the river volta; that is Akosombo. The lake is bordered by 6 Political regions of Ghana namely, Eastern, Volta, Oti, Bono East, Ashanti and Savana regions. It has a surface area of about 8,500km (8,500ha); with average depth of about 20m. Four major rivers flow into the lake; namely, the White and Black Volta, Oti and the Afram Rivers.
AQUACULTURE: With volume of fresh water available all season, the Volta-lake provides the best water resource for intensive aquaculture farm in Ghana. Presently, the largest Tilapia production farm in Africa; the Tropo-Farms, also called the Volta Catch operates on the Volta Lake. It produces about 10,000mt of Tilapia annually and sells daily locally through its sales points in the country. There are many other intensive commercial Aquaculture operating on the Volta-lake as well as small-scale sizes. Even though there are other competing human activities on the lake, such as Water Transport and Artisanal fishing of fresh water fish, the lake by its large surface area can contain hundreds of intensive commercial farms. Some of the natural aquatic or fish species in the lake include Tilapia, called the Volta or Akosombo strain, Heterotis some Anchovies and Demersals, clams, Shrimps, Mullusc and many others.
???????RISK: Just like any other Aquatic projects, Aquaculture on the Volta-lake comes with risk most of which are human linked. In the case of the Volta-lake, we have the communities around the lake that farm and fish at the banks and in the water respectively.
- Flooding as a result of continuous heavy rains sweep land sediments into the lake thereby causing an under-water upwelling that distress the fish and cause massive fish death at certain parts of the lake. This phenomenon is mostly recorded down-stream of the hydro system.
- Climate change also affect the temperature and the flow of the lake. The high winds in the evenings after the high temperatures (cooling weather) stress up both the fish and the holding system.
- Annual inflow of massive water from the spillage of the upstream Dam in Burkina-Faso and unusual heavy rains in the Northern part of Ghana also cause the lake to overflow its banks and force the Management of the Hydro-power the Volta River Authority to also spill the dam.
- This also cause the lake to overflow and flood communities and projects down-stream with subsequent massive distinction especially to human habitation and Aquaculture. This massive flooding normally occurs in 10years intervals.
- Massive Tree stumps in the lake as a result of the creation of the Dam that caused the water to overflow the heavy tropical forest surrounding bank of the River Volta also disturb Aquaculture activities on the lake
ACTION AND MITIGATION: there are Ghana Government Agencies that regulate and offer extension services to the Aquaculture Industry. These extension Officers come from the major agencies such and the Fisheries Commission, Council for Scientific and Industrial Research (CSIR), Environmental Protection Agency (EPA), Water Resource Commission (WRC) and the Volta River Authority (VRA). - The VRA has an all-round ferry that helps to uproot the tree stumps and clears the space for the installation of cages.
- The extension service providers help farmers with best practices so they are not adversely affected by the climate change and the weather patterns.
- The VRA gives out the historical data of the lake as an early warning system for the farmers to use for their migration plan.
- Flooding or overflow of the lake causes lots of damage to Aquaculture and so the VRA always draws the attention of the farmers when they sense its approach.
- The VRA officers give the necessary advice to the farmers so as to minimise damage to both human and the farms.???????
WAY FORWARD. The Volta-lake in spite of the other human activities and risks still has the capacity to take on about 500 more high intensive commercial farms with average production capacity of 5000mt per annum as well as about 1000 mid-level commercial farms, with annual production of about 2000mt Tilapia. The Ministry of Fisheries and Aquaculture Development is collaborating with these Agencies to prepare bathymetric zoning data on the Volta-lake to enable investors get access to areas prepared for particular types of cage systems to aid investment in Aquaculture on the lake.?????
