German project brings RAS Grouper farming to Europe from Australia

A German consortium has successfully introduced Queensland giant grouper (Epinephelus lanceolatus) farming in Europe using recirculating aquaculture systems (RAS), in collaboration with Australian grouper farming expert Ecomarine Group.

The OPTI-RAS project, led by the Alfred Wegener Institute (AWI) together with RAS shrimp and fish farming specialist Oceanloop and catering group Sander, has developed protocols for land-based grouper farming, focusing on feed efficiency, stocking densities, and bio-economic modeling.

"We see great potential in farming this species. Growth, feed conversion and survival are excellent and, together with the stocking densities that can be achieved, this species can be a very sustainable marine fish species to be farmed,” said Dr Bert Wecker, CTO of Oceanloop, in a press release announcing the project results.

The team imported grouper fingerlings from Australia and found that the fish adapted well, with survival rates reaching 99% and economic feed conversion of 1.0. The consortium reports that high-density farming of up to 200 kg/m³ showed no negative effects on growth or stress levels, highlighting grouper’s potential for aquaculture.

Oceanloop said that its custom grouper feed resulted in improved growth rates, allowing fish to reach 3 kg within one year. The German company, which is best known for its development of indoor shrimp RAS farming, reported successful results from a farming trial at its R&D system in Kiel, which showed a 99% survival rate, with stocking densities ranging between 80-120 kg per m³.

Initial sales have begun through a Oceanloop’s sister company, the seafood distributor Honest Catch, with the fish featured on the menu of Saltzburg Michelin-starred restaurant Ikarus, and later launched under the “Good Grouper” brand.

"We're proud that the Opti-RAS project has provided valuable insights into the commercialization of grouper farming in European RAS and that this promising species has already found its way to seafood lovers," added Mirko Bögner, project coordinator at the AWI.

The consortium partners stated they see grouper as "an important piece of the puzzle for the development of RAS aquaculture, as it requires suitable species with attractive price points", describing the species as "a potentially high-performing fish for RAS farming".

The project is funded by Germany’s Federal Ministry of Research and Education (BMBF) under the Innovation Space Bioeconomy on Marine Sites (BaMS).