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Innovative management system for tilapia fish farms cuts feed costs

System uses circular aluminum tanks that float on rafts of plastic bottles releasing a correct dose of fish food 48 times per day. The new method also reduced mortality in 12% by dispensing switching of tanks in fish grading

Fundação de Amparo à Pesquisa do Estado de São Paulo

An innovative tilapia farming system that reduces both expenditures on fish feed and mortality rates, among other benefits, has been developed by Brazilian firm Fisher Piscicultura and is undergoing final testing on the Grande River, near the border between São Paulo State and Minas Gerais.

The innovation consists of the use of round aluminum tanks floating on rafts made up of PET bottles of the type used as containers for soft drinks. Screens inside the tanks separate larger from smaller fish, facilitating their classification. An automatic feed dispenser is controlled by a timer that runs on solar power.

"Our floating circular tank design optimizes the production system. Most fish farmers have traditionally used square tanks. Also, feed is manually dispensed by personnel using a handheld can three or four times a day. In our system, the tanks are round and have a silo in the center holding 1,200 kg of feed. An automatic dispenser releases the right dose 48 times a day," says Hélio de Souza Barbosa, a partner in the firm. Barbosa is responsible for the designing the project, which had support from the São Paulo Research Foundation through its Innovative Research in Small Business Program (PIPE).

"The timer modulates the feeding process and improves shoal homogeneity," Barbosa says. "A fish that eats regularly is always satiated and eats only what it needs." Feed accounts for 70% of production cost in conventional tilapia farms, according to David Pulino, the firm's other partner. He has not yet estimated a final number for expenditures on feed using the technology developed by the firm but believes it to be less than 70%.

In Brazil, tilapia farming is a growing industry requiring cost-saving technology to compete in the global marketplace. In 2016, tilapia production was worth BRL 1.335 billion, according to the national statistics bureau (IBGE). The Nile tilapia (Oreochromis niloticus) is the most widely farmed fish in Brazil, which produced 357,639 metric tons in 2017. The country is the world's forth-largest tilapia producer, behind China, Indonesia and Egypt.

Higher productivity

With support from FAPESP's PIPE program, Fisher is finalizing a project begun in 2016 to analyze commercial fish farm management in experiments with tanks that hold 60,000, 80,000 and 100,000 fish.

The principal investigator for the project is animal scientist João Donato Scorvo Filho, a retired researcher affiliated with the São Paulo State Agribusiness Technology Agency (APTA), which is under the authority of the state's Department of Agriculture & Food Supply. Other APTA researchers are collaborating.

"In the first PIPE project in 2014, we performed tests in a tank with 20,000 fish to verify technical feasibility and to detect and remedy points of failure. We're now doing a complete survey of the parameters and the entire production system," says Scorvo Filho.

The tank was designed by Barbosa and built by the firm's engineers. Before establishing Fisher, Barbosa managed a fish farm with more than 1,000 conventional tanks. The production process was manual and required a large workforce, with many employees doing "hard labor". It also required a large number of boats to achieve the desired productivity. "I designed the new tank to save on cost and labor while raising productivity," Barbosa explains.

The firm submitted both projects to FAPESP after building the first prototype. In addition to enhancing the technology, the projects systematize a new management solution that can be sold to other producers. "We're gleaning results to document and establish a production mode and business plan with better results than those of traditional fish farming in Brazil," Barbosa says.

For Scorvo Filho, initial investment in this new business model will be higher than in the conventional management system because the technology is more costly, but the service life and production scale will be far greater, and the payback period will be shorter.

The circular tank, which has an inner diameter of 12 m and a depth of 4.5 m, is lined with wire mesh to prevent incrustation by the Golden mussel (Limnoperna fortunei), a freshwater mollusk brought accidentally in the ballast of ships from Asia. This mollusk is a pest in rivers of Brazil's South and Southeast regions and is already present in some rivers of the Center-West.

Netting pens with different mesh sizes are arranged according to the producer's management needs to facilitate fish grading and help reduce mortality. In the conventional production system, tilapias have to change tanks on reaching a certain size. This procedure involves removing them from the water and leads to many deaths.

In Fisher's system, the fish are not removed from the water to switch tanks. The larger fish are driven by the pens into a container shaped like a triangular fryer basket, which is moved under water out of the central circle and into another tank. "Once they reach approximately 330 g, we place them in other tanks, where they're finished for slaughtering at 900 g," says Barbosa.

A patent application for the entire system has been filed with the National Industrial Property Institute (INPI). "Tilapia mortality exceeds 20% on most conventional fish farms. Our own rate is currently 8%, but our goal is to lower it to 3%-5% maximum," Pulino says.

Another advantage, according to Fisher, is the ease of maintenance and cleaning, including the removal of mussels. Fisher's tank is raised above the water by the injection of air into a drum at the bottom of the aluminum structure. Traditional fish farms use a crane mounted on a barge to lift the tank or hire divers to do this work.

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Fisher was founded in 2011. Its head office is in Belo Horizonte and has a branch office in Riolândia, a small town in São Paulo State on the Grande, where the system is being tested. It has licenses to operate in the Água Vermelha reservoir from CETESB, the state environmental agency, and the federal ministry in charge of fisheries and aquaculture.

In addition to the partnership with APTA in its PIPE-FAPESP projects, Fisher is collaborating with researchers at São Paulo State University's School of Veterinary Medicine & Animal Science (FMVZ-UNESP) in Botucatu to perform studies on technical indicators such as weight gain, food conversion and limnological parameters for the aquatic ecosystem and on the development of the automated feed dispenser, which was designed by Claudio Angelo Agostinho, a professor at UNESP.

About São Paulo Research Foundation (FAPESP)

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. For more information: http://www.fapesp.br/en.

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