In mid-February, the Aquaculture Competence Centre at the Klaipėda Science and Technology Park (KSTP) completed one of the main applied experiments of the international ProRMAS project, aimed at evaluating the suitability of alternative proteins for shrimp feed. The five-week study represents an important step toward developing more sustainable, circular-economy-based aquaculture systems.
Three feeds – one goal
The experiment was conducted in a 30 m³ closed marine aquaculture system at the Business Incubator of Klaipėda Science and Technology Park, focused on the cultivation of whiteleg shrimp (Litopenaeus vannamei). The study aimed to assess growth and survival rates, the efficiency of the recirculating aquaculture system (RAS), and the levels of generated sludge and effluents.
Three types of shrimp feed, developed by project partners from the Alfred Wegener Institute (Germany), were tested:
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Control feed – standard proteins from fishmeal and soybean meal.
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Experimental feed (50%) – 50% of fishmeal protein replaced with alternative proteins from polychaete worms.
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Experimental feed (100%) – fishmeal completely replaced by worm-based proteins.
Each experimental tank was equipped with a FIAP Belt Feeder Pro. The feeders were filled twice daily, in the morning and evening. Their operation relies on a slow-moving belt that distributes feed granules continuously throughout the day. The designated number of shrimp in each tank was fed according to their growth stage, and the feeders were refilled at 6 p.m. to ensure uninterrupted feeding. All feeds were formulated to meet the nutritional requirements of intensively farmed whiteleg shrimp.
Circular system: turning waste into resources
The main objective of the ProRMAS project is to develop a sustainable and efficient seafood production system – a Recirculating Multitrophic Aquaculture System (RMAS) – that closes the organic matter loop, produces high-quality proteins, and maximises the efficient use of water and nutrients. Beyond a fully functional RMAS, each output (shrimp, polychaete worms, macroalgae, plants, and processed sludge) will also be analysed to ensure sustainability and market value.
During the project, all partners will cultivate whiteleg shrimp together with polychaete worms and macroalgae to varying extents. This multitrophic approach allows nutrient cycling and reduces organic waste: worms consume sludge generated by mechanical filtration, while macroalgae absorb dissolved nutrients. This system produces sustainable feed while simultaneously:
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reducing solid organic pollution,
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optimising nutrient utilisation,
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creating a valuable alternative protein source for feed.
This approach simultaneously addresses both waste management and protein shortage, closing the loop between pollution and protein production within a single system.
Growth and health – the main evaluation criteria
The growth study of Litopenaeus vannamei covered the entire period from juvenile to market-size shrimp (15–25 g). From the start of the experiment, measurements of weight (±0.1 g) and length (±0.1 cm) were taken every two weeks, overall health status was evaluated, and biological samples were collected for further analyses.
The health index was calculated based on multiple indicators: condition of antennae, eyes, rostrum, tail, legs, muscles, gills, and exoskeleton, stomach content, hepatopancreas condition, and other parameters. For some individuals, hepatopancreas samples were collected for digestive enzyme analysis and sent to project partners in Germany for detailed laboratory testing.
Results – preparation for analysis
Data collected during the experiment are currently being compiled and analysed. The study will assess whether alternative polychaete worm proteins are as effective—or more so—than traditional fishmeal and soybean proteins, considering growth rate, survival, feed conversion efficiency, and overall health.
The results will be presented in scientific publications and technology evaluation reports. They are expected to contribute to the development of more sustainable feeds and strengthen the potential for environmentally friendly shrimp production in Lithuania and across Europe.
The experiment, completed on 12 February, marks a significant milestone in the ProRMAS project – transitioning from laboratory trials to comprehensive evaluation, which will demonstrate the feasibility of a circular, nearly zero-waste marine aquaculture vision.
