Extension service

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Where we can help to farmers?

1.    Bio-economic optimization of biomass management and tank-layout design in multi-tank production systems
Farmers who produce fish year-round in a series of tanks (or ponds, cages) with more than one rearing phases and sorting events (e.g. fingerling rearing, yearling rearing and grow-out phase) usually face with the problem of decision between multiple solutions for
•    the number of tanks dedicated to each rearing phase  
•    the length of each rearing phase
•    arrival frequency of juvenile batches
•    the number of sub-batches to be formed after sorting event (between two growing phases)
With an optimal management plan for the biomass flow the farmers can maximize their production in a given production system (given number and volume of tanks) using given rearing technology (given growth rate and marketing size) simply by optimized allocation of tank space to the fish biomass that is changing dynamically.
However feeding costs and juvenile costs are not affected by the utilization level of tank capacities, reduction in water & electricity costs and in fixed costs per kg fish can be achieved by increasing production level in a given production unit.







Two different biomass transition figures in a 14-tank fish production system with a farmed species that has a rearing cycle of 360 days

The extension service of NARIC HAKI can help farmers to optimize their biomass management by bio-economic programming. We can also help to aquaculture investors to minimize the tank volume to be built if they fixed the desired production level (e.g. 100 t/year) and the rearing technology for the species to be farmed.

Contact: Gergő Gyalog;; +36 66 515 322


2.    Improving cost effectiveness of fish feeding

Cost effectiveness of fish production can improved by manipulation of feeds and feeding technologies in the following ways, or in the combination of these:
•    reducing the cost of feeds by the utilization of cheaper, alternative ingredients in the feeds
•    improving the efficiency of digestibility of the used feeds by using additives (exogenous enzymes, pigments, probiotics, etc.)
•    applying higher quality feeds that enables the farmers to increase yields (kg/ha) so that they can  reduce the fixed cost per unit of fish produced (€/kg fish produced).

Successful inclusion of different cheap ingredients (plant and animal by-products) in the fish feed without compromising growth has been proven by HAKI as a viable way to decrease cost of diets for different species, like carps and catfish.
Employees of HAKI have also expertise in the inclusion of different additives as per the requirements of the ingredients included in the applied feed.  
Accurate information provided by farmer to HAKI will help them to optimize the feeding strategy by bio-economic calculations.



Based on our expertise on fish nutrition and feeding technologies we can give tailor made service to farmers paying special attention to all dimension of sustainability. We are also opened to do new research based on farmers’ suggestions about new ingredients based on their market availability and price.

Contact: Dr. Shivendra Kumar;; +36 70 4918892
Dr. András Rónyai;; +36 66 515 320

3.    Effluent and waste treatment in constructed wetlands

There is a growing environmental concern over the disposal of effluents from intensive aquaculture and animal breeding units. Thus farmers are obliged to seek cost efficient and environmentally sustainable waste treatment technologies to comply with the increasingly stricter regulations.
Research results from HAKI proved that constructed wetland systems consisting of fish ponds stocked with herbivorous species and water plant ponds connected to each other are capable to retain 70-80% of the nutrients from the effluents and at the same time there are valuable by-products during the treatment process.

Based on our expertise our staff can help with customized design of wetland system to farmers who are ready to invest in to environmental protection activities.




Contact: Dr. Éva Kerepeczki;; +36 66 515323



The development of the webpage (in 4 languages) has been 
supported by the AQUAREDPOT project funded by the European Commission (FP7-316266).