Mariculture Technical Innovations in Sweden (MARTINIS)

The overall goal of this project is to develop novel land-based marine recirculating aquaculture systems (RAS) with a reduced nitrogen footprint. Fish waste contain ammonia/ammonium, which is toxic to the fish. In traditional RAS, ammonium is converted into less toxic nitrate, via nitrite, by nitrifying bacteria.

However, these compounds, especially nitrate, will accumulate with time in RAS and negatively affect the health and welfare of the fish.

This requires regular water exchanges that in turn may cause eutrophication in the ocean.In this project, we will test several alternative nitrogenous compound-filtering technologies for RAS: anammox bacteria that convert ammonia and nitrite directly into nitrogen gas; membranes that are well established techniques for water treatment and sanitation, able to remove nitrate from the water, and macro- and microalgae as efficient nutrient remediators.We will first determine the nitrogenous compound-removal capacities of each of these technologies before implementing them in a pilot RAS, where we will evaluate the interactions between the different compartments on the water quality.

Finally, we will assess the growth performance, health, welfare and product quality of fish reared in this new culture system.

The results of this project are a key step to establish a local, high quality and sustainable aquaculture in Sweden that will meet today’s consumer standards.