Fish is an important source of protein for millions of people throughout the world yet the world’s natural occurrences are unable to meet the rapidly growing demands for fish.

Breeding fish using aquaculture may help to protect natural resources and ecosystems, while improving for food security.

However this is only possible if conducted within sustainable technology where environmental, economic and social aspects must be taken into account equally.

As such scientists at the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) in Berlin Germany are conducting research in fresh water fish breeding using aquaculture and aquaponics technology known as Tomato – Fish technology.

Already Uganda’s scientists at the National Fisheries Resources Research Institute jointly with their colleagues at the Aquaculture Research and Development center in Kanajasi have conducted research using the above technology and deployed it to farmers who are breeding Tialpia and African Cat fish across the country.

However there are lessons Uganda’s scientists and farmers can learn from the Germany experience.

Background

IGB is Germany's largest and one of the leading international research centres for freshwater fisheries.

The scientists here include hydrologists, biogeochemists, physicists, microbiologists, evolutionary ecologists, fish ecologists and fisheries biologists conducting research with their colleagues all over the world working under one roof.

The institute collaborates with 70 research institutes across the world with a budget of 14.7 billion Euros in the area of aquarium, climate change, fresh water invasive species, and aquatics leaving in cold water bodies as well as people rearing Amphibians including cold water fish species.

Currently the fish ecologists and fisheries biologists began a trail focusing on use of aquaculture and aquaponics technology known as Tomato – Fish technology which is combined fish and vegetable farming with the aim of saving usage of water, energy, artificial fertilizer and space.

They are doing this with an aim to reduce emissions in food production. The scientists are also using their expertise in fish genetics and reproduction to protect the fish species of interest.

The team communicates their research outcomes to different stakeholders and practicing partners in a targeted manner ensuring that the scientific findings are transferred to practicing farmers and partners without delay. 

As such the reporter caught up with the scientists at the Institute and below are the details.

What scientists at the Institute are doing?

Nadja Neumann the communications officer of the Institute giving background of the IGB noted that Institute is an arm of the Leibniz Association and it was found in 1995 located in Berlin and Brandenburg.

It is an association of 97 independent institutes organized in thematic sections with regular exchange programmes in a disciplinary cooperation in research alliance and networks on knowledge based evidence.

“Our core aim is to research for future of our freshwaters with our scientists seeking to understand fundamental processes that shape our fresh waters and their biotic communities. We investigate how these systems respond to natural and anthropogenic environmental changes,” she notes.

The institute cooperation contains 11 joint professorship with 4 universities and they have contractual agreements with 70 research institutes across the world and 390 employees.

Aquaculture and aquaponics research

Global challenge of feeding the world

Professor Werner Kloas the head of department fish biology, fisheries and aquaculture explained that by 2050, the world will need to feed 2 billion or more population and this is possible using advanced technologies developed by scientists such as high quality animal and fish protein.

However there is the challenge of shrinking resources which include, space, water, nutrients, animal and fish protein, pollution, climate change, over fishing, war, pandemics and negative impacts caused by unsustainable farming practices.

He recommends that global demands require a change in concept of water, energy and nutrient management footprints as well as reduction for water food energy nexus.

This can be done by communities saving water use, its reuse, recycling nutrient management, energy saving and alteration of energy use.

Aquaculture technology

Prof Kloas defined aquaculture technology as rearing of aquatics organisms such as fish, mussels (crocodiles) and plants under a confined controlled condition including artificial reproduction, nourishing and protection against diseases and their enemies.

To him if farmers adopt this technology which most of them have done including those in Africa and Uganda, this will save the fresh water resources because closed recirculation of the technology in indoor facilities will lead to protection of the environment and no gas emissions into the environment.

Global fish production

He contends that fish is globally the largest protein nutrition for humanity with aquaculture the fastest booming sector of agriculture at a rate of 3.8% per annum therefore any further fish production relying on this technology will of advantage.

Apparently the statistics indicates that human nutrition from aquaculture fish stands at 85 million tons per arum compared to capture fish at 73 milIion tons per annum.

This technology has its advantages because reduction in water foot prints can be equated to 600 biomass relating to 1,500 litres water usage in terms of fish breeding and figures differ for chicken, cattle and pigs. The efficiency of water user is 5%-10% per day.

However the disadvantage is that it’s a high technology investment which may not be affordable by ordinary small scale farmers.

Non sustainable aquaculture; use of genetically modified organisms

Apparently scientists in USA have modified Frankenfish species which is mix of salmon fish species and ocean pount (macrozoarces americananus).

However the scientists believe this may not sustain the world demand therefore the intervention of aquaculture and aquaponics technology.

Aquaponics research

Prof Kloas and his team define aquaponics technology as the coupling of fish aquaculture with plant production such as vegetables for saving resources.

The team has conducted research using this technology where various fish species ranging from African Tilapia, African cat fish, Beacon fish species and the genius Arapaima (pirarucu) native to the Amazon and Essequibo basins of South America using the required principal where the tomatoes are grown from the nutrient obtained from fish breeding process.

The general principal in aquaponics farming is that farmers can breed the fish species in drum containers with sediment system as filter mechanism.

This is after filling the containers with clean water and the fish are fed using required nutritious feed as well as providing water fertilizer nutrients for the fish to stay in fresh.

In countries such as China farmers practice this technology in paddy rice fields where fish is bred in water in the rice fields and it has worked well in a natural environment.

Scientists have to optimise the PH of the water because fish require water PH 7 and for plants it has to be lower

However the experiment Prof Kloas conducted showed they were able to harvest 300gms of tomatoes and each Tilapia for instance grew weighing 10kg with use of 10 liters of water.

The fish feed of 32% protein are required tilapia but for salmon fish is 50-60% 

The scientists discovered that fish species differ in protein meal consumption and it is only fresh water fish species that can grow well and survive without fish meal.

Comparison of fish feed and water foot prints

For 1kg of fish biomass the protein content for Tilapias is 32% and the fish feed is 1.5kg-2kg with carbon emission of 1.3 kg which is negligible.

The team concluded that farmers in Germany and other parts of Europe can apply this technology by growing fresh water fish species while growing tomatoes or any other vegetables.

As long as they follow the principle of filtering water and keeping it clean to run into the area where tomato is growing, they will be able to harvest twice, fish and vegetables.

Ugandan perspective

In Uganda there has been an initiative where a team of scientists trained under a three year project run by the Korea International Cooperation Agency (Koica) through Chonbuk National University in collaboration with Makerere University College of Agricultural and Environmental Sciences (CAES) established a smart hydroponic technology at Makerere University Agricultural Research Institute Kabanyolo (MUARIK) farm with sensors controlled panels.

The sensor internet based technology is already being explored in Uganda at MUARIK farm by scientists who went to study in South Korea and are implementing their practical study experience.

They set up a smart hydroponic farm which is internet control based and one of the important tools which controls the entire greenhouse farm is the control panel.

Papius Tumusingiize with expertise in Agricultural Convergence Technology explained that interacted the function of the control panel in the growth process of Tomatoes in a hydroponic greenhouse farm.

The control panel contains electricity switches in an automatic mode and manual form. It contains fuses which protects the entire panel system and other sensors in the greenhouse.

The team harvested tomatoes for continuous 9 months and the technology is now being adopted by commercial farmers growing tomatoes on large scale.

Other farmers are also breeding Tilapia in drums and using the filtered water as manure to grow yams.

One such a farmers is Mr Charles Mulamata’s family located in Budo Kisozi village about 7km off Kampala Masaka road I who are engaged in fish breeding using Aquaponics technology not necessarily for consumption but as a business initiative.