At a time when fish stocks are declining globally due to factors such as climatic change and pollution, cage fish farming technique, has become an encouraging alternative that yields 10 times the ‘fish catch.’ compared to ‘fish reared’ in ponds,or in the sea. The West Africa Agriculture Productivity Programme is working with the private sector to boost fish production nationwide, DANIEL ESSIET reports.
Phil Onuoha produces fish seed and is a grow-out farmer. His interest in farming started while he was young, having been born in a fish farming family.
Then, they never had the technology and the infrastructure and were not able to bring in scientists to teach them fish hatchery management and practices.
He wanted to enlighten farmers that they could make money from the trade as well as improve their diet as fish is highly nutritious. He rears catfish and sells fingerlings to farmers who then rear them. According to him, fish farming has been identified as a way to help farmers achieve middle-level income.
His farm, aside from producing fingerlings and grown-outs, provides education on fish farming to interested farmers and institutions.
At one point, a competitor poured poison into his water source and his uncle recorded massive losses. This made him to think and do more research on how to address the issue of water supply. He said farmers spend a lot of money on generator in most cases to ensure that water supply activities at their farm go on uninterrupted. The cost of fuelling eats deep into whatever gains the farm would have made.
To address this problem, Onuoha said the government and the private sector should encourage Nigerians to practise fish cage farming, which will require them utilising the abundant natural sources of water. According to him, the rivers and estuaries in Nigeria are extremely suitable sites for fish cage farming.
The streams and rivers, therefore, offer opportunities for pond culture, while the larger rivers and lakes offer opportunities for intensive cage culture. Onuoha said locating fish farms within water bodies is crucial and most productive and would bring returns to the investors.
Generally, cage fish farming involves the use of nets mounted on metallic frames to form a cage. The cage is placed in a specific area, where it floats on water. The method is cost-effective and increases inland fish production substantially, he said.
The fish, such as tilapia, mature between six and eight months. Under this procedure, fish rearing is done in an enclosed area in a natural aquatic environment where the water continuously flows without accumulation of debris, which is why there is no pollution or ammonia deposition as in the case of stagnant and low density water ponds.
At the end of the culture period, which ranges from six to eight months, three to five tonnes of fish are produced just from one cage.
The biggest advantage of cage farming, according to Onuoha, is that despite being a fish culture technique, there is no need to change the water as sea water continuously flows through the cages, there is some natural food easily available for the fish to feed on and there’s no need to put up any time or space-consuming infrastructure except the cages.
However, not all areas are suitable for cage farming. There needs to be optimum depth of at least 10 metres from the shore, the sea should be more or less calm without high waves and currents where the cages are located. The salinity, ammonia, nitrate should be all within permissible limits, according to experts.
Cage culture is a new method developed in recent times. According to experts, a stock of about 1,500kg can be accommodated in a cage of two metres length, two metres wide and two metres deep
The disadvantage is that cages can only be used in water which is more than five metres deep.
China has recorded a success story in cage culture and marine fish cage culture.
Head of Trade, Marketing Department, Green Agriculture West Africa (GAWAL), a subsidiary of China General Construction (CGC Nigeria Ltd), John Wen, said his organisation is working with the West Africa Agricultural Productivity Programme (WAAPP), Nigeria to promote the development of small scale cage fish farms across the country.
The cage culture would be small-scale operation located onshore or in mangrove creeks, not far from farmers’ houses for easy management, security and saving of labour costs.
He said the company is cooperating with the Lagos State Ministry of Agriculture and Cooperatives for the promotion of fish cage culture by introducing advanced fish farming techniques from China. In 2013, the company signed a memorandum of understanding (MoU) with WAAPP-Nigeria for agricultural cooperation. The cooperation has covered construction of biogas digesters and fish cage culture projects, production and supply of rice and maize certified seeds.
Chief of South-South Cooperation, Food and Agriculture Organisation (FAO), Festus Akinnifesi, said since 2003, nearly 650 Chinese experts and technicians have been fielded in Nigeria for a minimum of two years. The experts are deployed in all the country’s 36 states and the vast majority of them live in rural communities. Once there, the experts share their knowledge, skills and experiences, and have helped introduced, demonstrated and enabled the adaptation of more than 200 Chinese-developed scalable technologies and innovations.
In Koton-Karfi, Kogi State, members of a recently established cooperative are waiting for some 4,000 tilapia to mature in eight bamboo-and-net cages anchored to the shore of a small lake. “Traditionally we fish by setting nets, but we’re never sure how much we’ll catch,” explains 20-year-old Al Hassan Tijani.
“With fish cage culture, we know how many fish we will harvest, and how much we will earn,” he added.
