Food production systems are facing increasing pressure to produce more while using fewer resources. In many regions, especially Southern Europe, water availability is becoming a growing challenge as prolonged droughts, changing climate conditions and increasing pressure on freshwater resources affect traditional food production systems.
At the same time, large amounts of saline and brackish water remains unused in conventional agriculture. The ProRMAS project asks a simple question: what if these limitations could become resources instead?
To address this, ProRMAS is developing and testing a Recirculating Multi-Trophic Aquaponic System (RMAS) that combines shrimp production, polychaete cultivation, macroalgae, plant production and nutrient recovery within one circular production concept.
For Matthew Slater, Head of Aquaculture Research Group at the Alfred Wegener Institute, this practical relevance is one of the reasons the project matters now:
“We hope to show real and practical RAS system methods that people can use in water-limited environments to produce sustainable food. This can benefit partner farmers in Italy, for example, where water scarcity for food production is becoming a regional problem.”
Rethinking waste in aquaculture
One of the central ideas behind ProRMAS is simple: waste from one part of the system could become a resource for another. For this reason, researchers are investigating whether nutrients and by-products generated during shrimp production can be reused instead of discarded. Polychaetes or marine worms that have high nutritional value, are cultivated using sludge generated during shrimp farming. Then the worms were later tested as feed ingredients for shrimp diets.
At the same time, sludge and residual materials are being tested for their potential use in plant cultivation systems and analysed for their nutrient composition and fertilizer potential. This challenge is especially relevant for recirculating aquaculture systems, where solid waste management can directly affect production costs.
As Marco Birolo from the University of Padova explains:
“In ProRMAS, residual nutrients and organic matter are not simply treated as waste. We look at how they can become new biomass, feed ingredients, food products or biofertilizers.”
Testing ideas under actual operating conditions
Researchers are currently evaluating alternative feed ingredients, nutrient recovery approaches and different production methods under controlled conditions. Shrimp diets containing polychaetes and the macroalga Ulva lactuca are being tested as alternatives to conventional feed ingredients. And an important milestone has already been achieved. According to Isabela Pinheiro from the Alfred Wegener Institute:
“One important milestone so far has been producing polychaetes using shrimp farm waste as the sole feed source and successfully testing polychaete meal as an alternative to fishmeal in shrimp diets.”
Experimental work has also progressed on system development itself. At Klaipėda Science and Technology Park, researchers Nerijus Nika and Gintautas Narvilas are directly involved in experimental activities related to shrimp production, polychaete cultivation and the operation of research systems supporting the project’s practical implementation.
Matthew Slater highlights one of the important technical achievements so far:
“Solid waste feeding to polychaete worms and installation of the new polyrack system.”
Early observations suggest strong shrimp interest in polychaetes, while Ulva lactuca is also showing potential as a feed component. Researchers emphasize that many experiments remain ongoing and that results still require further analysis.
More than experimental systems
The project creates value beyond research results alone. Demonstration systems and pilot infrastructure support technology development, strengthen competence in recirculating aquaculture, and create opportunities for students and young researchers to work with circular production approaches. For partners such as Klaipėda Science and Technology Park, this also means building expertise through hands-on experimental work and the operation of research infrastructure.
As Nerijus Nika from Klaipeda Science and Technology Park explains:
“Participation in ProRMAS contributes to strengthening expertise in recirculating aquaculture while creating opportunities for students and young researchers to work with emerging production systems and circular approaches in practice.”
The multidisciplinary structure of the project is another important aspect. Researchers working in aquaculture, feed development, horticulture, nutrient recovery and environmental assessment are contributing to a shared goal: understanding how such integrated systems function under actual operational conditions.
Building the next phase
The next phase of ProRMAS moves beyond individual experiments and closer toward integrated operation. Researchers will continue optimizing production systems, evaluating biomass quality, and advancing demonstration infrastructure across partner countries. One major milestone still lies ahead.
As Matthew Slater puts it:
“Our goal is to run the pilot farm with all 4 species: worms, shrimp, ulva lactuca and salicornia.”
For Isabela Pinheiro, the interaction between these system components remains one of the most interesting aspects of the project:
“What I find most interesting is connecting different trophic levels in a way where one organism’s output becomes a resource for another. That is where the real potential of these systems lies.”
As water resources become more limited and demand for food continues to grow, projects like ProRMAS explore how underused resources could become part of future food production.
“The project ProRMAS was carried out under the Green ERA-Hub, a Coordination and Support Action (CSA), funded through the European Union’s Horizon Europe research and innovation (R&I) programme under Grant Agreement No. 101056828.”.
This international research and development project is supported by the Ministry of Agriculture of the Republic of Lithuania, the Federal Ministry of Education and Research of the Federal Republic of Germany, and the Ministry of Agriculture, Food Sovereignty and Forestry of the Republic of Italy.
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