Where does the fish water go?
Aquaculture is the farming of aquatic organisms. The Santander demonstration is part of AQUALICIOUS, a European project exploring ways to use resources from one farmed species for another. Its fish are thicklip grey mullet, and their effluent is water carrying waste from the fish. The diagram shows two separate paths for that water.[1]
- Fish-farm effluent → microalgae
- Fish-farm effluent → marine worms
- Microalgae → resource for growing oysters
The worms and microalgae are separate uses of the fish effluent. The oysters are not shown using fish waste directly.
How do oysters fit in?
In the Santander design, microalgae are the middle step: they provide a resource for growing oysters, rather than the oysters being given fish waste directly.[1]
What still needs testing?
AQUALICIOUS plans demonstrations in Norway, Belgium and Spain to test its technologies. In its October 30, 2026 report, Spain’s CSIC said the project aims to improve sustainability and efficiency; it did not report proven gains. The project began in late September 2026.[1]