From salmon sludge and manure to fertiliser: a circular economy around land-based salmon farming

Introduction

Human population is growing, and neither aquaculture nor agriculture are adapting to overcome this challenge sustainably. On the one hand, fish production must increase, but sea-pen aquaculture is facing pollution, spreading of disease, and water eutrophication. On the other hand, animal manure is the primary source of ammonia emissions and nitrate leaching.

Challenges in Fertiliser Production

Fertilisers are needed to ensure food security. However, raw materials imports are limited, fertiliser production processes are high-energy intensive (2% of the world's energy), and phosphates scarcity has raised fertiliser prices by 80% in the last year.

Project Overview

Terraforming LIFE designs and develops new technologies and methods to create an Integrated Agriculture Aquaculture (IAA) system where aquaculture, agriculture farmers, and agriculturists are at the heart of a circular economy.

Technology Optimization

This project optimises a new water recycling technology (Sideflow), complementary to the Flow-Through System with Reuse (FTS-R) aquaculture system. Both CAPEX and OPEX will be lower than any other high-tech aquaculture system (e.g., sea-pens, Recirculation Aquaculture System (RAS), and hybrid systems) while maximising the amount of nutrients from fish sludge.

Bio-Fertiliser Production

A combination of processed sludge and animal manure will be transported by a mobile treatment unit to a bio-fertiliser plant. Lastly, it will be boosted with digestate from any dead fish that unavoidably perish during the rearing, and eventually dried to create a powerful natural fertiliser and biogas.

Expected Outcomes

Within five years beyond the end of the project, we will implement 6 IAA systems (one in Iceland and five more across Europe), generating:

1. 138 new FTE
2. 3.9 billion of revenue - based on:
   • 0.5 Mt of salmon sales
   • 1.08 Mt of bio-fertiliser sales (0.82 Mt of landfilled manure and 0.25 Mt of salmon sludge)

This project will reduce 1.04 Mt of CO2 eq by shifting production from mineral to bio-fertilisers and avoid 0.08 Mt of CO2 eq due to ammonia evaporation from landfilled manure.