The project aims to set up a seaweed refinery for the production of high-quality seaweed biostimulant and fibre, usable as a semi-finished product in the manufacturing industry. Biostimulant is also applicable as a fertilizer in (organic) agriculture. Coastal force develops a fully circular production method with CO2 reduction and nutrient recycling as positive output. The project reduces fossil plastic within the industry and the production method ensures freshwater production and CO2 retention. The CO2 reduction through the use of seaweed is 50% for the fertilizer and even more for the bioplastic. Coastal strength contributes to training and the labour market by developing learning lines with regard to protocols, EU regulations and standards within the maritime industry and the manufacturing industry. Holdfast and Stipe supports 36 apprenticeships and aims to train large numbers of employees in the chain.