On the slopes of Mount Igueldo in San Sebastián, where a large fish farm once operated, abandonment now reigns. The concrete tanks, built back in the late 1980s, have long been void of fish—the last attempts to revive production ended almost twenty years ago. Since then, the area has become a haven for street artists and overgrown with bushes, while local environmentalists have repeatedly called it an eyesore for the city.
However, the situation may change dramatically. The biotechnology company Algaloop has proposed breathing new life into the abandoned site by turning it into a center for cultivating marine microalgae. In December 2024, the company applied for a permit to launch the project in the Agiti bay. The main idea is to use the old tanks for intensive cultivation of dunaliella salina, a microalga valued for its applications in agriculture, cosmetics, and even biomedicine.
The project has already received preliminary approval from the regional water resources agency. The authority did not identify any environmental risks, since the operation does not involve significant emissions or water pollution. The initiative is now at the public consultation stage, and anyone interested can submit their comments.
However, not everyone is pleased with these plans. The environmental group Eguzki is calling not for the launch of a new business, but for the restoration of the natural landscape, as required by local laws. They cite decisions by the provincial parliament and city authorities, who as early as spring called for the prompt ecological rehabilitation of Agiti Bay.
Despite the protests, project initiators are confident in its success. Anaut Patterson Mendiola, a biologist and head of Algaloop, points out that the existing buildings and pools are perfectly suited for algae cultivation. There are plans to convert an 800-meter building into a laboratory and warehouse, as well as to upgrade the seawater pools. By the third year, the company expects to harvest up to 25 tons of fresh macroalgae, and by the fifth year – to increase production to 150 tons. In the future, there may be an expansion of production or the launch of similar centers elsewhere.
The old farm, formerly owned by Culmanor, could become an example of how abandoned industrial sites get a second life. If the project receives final approval, San Sebastián could become one of Spain’s centers for sustainable algae production, with Agiti Bay serving as a platform for innovation in biotechnology.
