Technology transfEr for Thriving Recirculating Aquaculture Systems in the Baltic Sea Region

Pilot 2 - Geothermal resources and RAS

26 April 2023
Pilot 2 is focused on investigating the potential symbiosis between geothermal resources and RAS. The aim is to assess the feasibility of utilizing resources for the heating and mineralization of marine-brackish RAS to lower operating expenses and achieve energy efficiency.
Technical details


Pilot Owner: Klaipeda University

Location: Klaipeda, Lithuania

Partners involved: Klaipeda Science and Technology Park (LT), Blue Research (DK), University of Gdansk (PL), and Linas Agro Group (LT)yp

Type of symbiosis: water, energy (heat), and nutrients

Keywords: RAS, marine/brackish species, geothermal resources, water treatment, mineralization



RAS technology enables the growth of a diverse range of species, regardless of their location. In Europe, RAS is being used to cultivate warm-water species such as shrimp, offering consumers fresh and high-quality seafood. Another trend in RAS is the inland cultivation of marine species –away from seawater sources– using marine salt mixes to simulate seawater conditions. The use of artificial seawater can constitute a considerable proportion of the production costs.

Geothermal resources can be a valuable source of energy for RAS. Geothermal energy (heat) can be used to heat or cool water in RAS, reducing the energy costs and environmental impact associated with traditional heating and cooling methods. Furthermore, geothermal water is abundant in minerals like Na, Ca, Mg, Cl, and other trace elements. Moreover, geothermal brine closely resembles marine water composition, leading to the question of whether it can be used to replace artificial salt mixes in marine-brackish RAS.

In RAS, operational costs remain a significant challenge. Therefore, reducing production expenses could enhance the economic sustainability of these systems. Pilot 1’s objective is to assess the techno-economic potential of utilizing geothermal resources for the heating and mineralization of marine-brackish RAS.


Aim & Outcomes

The aim is to conduct a feasibility study that explores the techno-economic viability of using geothermal resources for heating and mineralization in large-scale saltwater RAS.
The study will focus on the Western Lithuania Geothermal Anomaly, examining the availability, distribution (vertical and spatial), physical characteristics, and technical requirements of these resources. Concurrently, a series of experiments will be conducted to evaluate the biological aspects of using geothermal resources in RAS. These experiments will assess the effects of hypersaline geothermal brine on the growth performance, physiology, element bioaccumulation, and meat quality of white shrimp (Litopenaeus vannamei) and rainbow trout (Oncorhynchus mykiss), in addition to RAS performance and water quality over the trial period. The experiments will also assess a system for geothermal brine storage and dosage. The experiments will be performed at Klaipeda University MRI Fishery and Aquaculture Laboratory’s RAS facilities.
Smart water use in RAS is vital for the growth of RAS in the future. In addition to developing alternatives to artificial sea salt, Pilot 2 will focus on reducing the usage of artificial saltwater by improving the water treatment process. To achieve this, Pilot 2 will concentrate on enhancing the denitrification process and using microalgae photobioreactors. There will be a strong collaboration between Pilot 1 and Pilot 2, as both pilots aim to develop more sustainable water treatment solutions.
Pilot 2 efforts will be summarized in:
  • A report of the evaluation of the biological, economic, and technical aspects of geothermal brine use in RAS and a guideline for its use in RAS systems.
  • A business case for large-scale shrimp RAS and geothermal resource application and sustainable water use.



Pilot 2 will contribute to generating the knowledge needed for pairing recirculating aquaculture facilities with geothermal resource users, such as geothermal power plants, spas, and other geothermal resource users.

Using geothermal resources in RAS can considerably improve its environmental and economic sustainability by reducing energy consumption and greenhouse gas emissions. Additionally, geothermal energy is a renewable resource not subject to price fluctuations or supply shortages, making it a reliable and cost-effective energy source for RAS.



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