REDROSE DEVELOPMENTS | Seaweed nutrient capture

REDROSE DEVELOPMENTS | Seaweed nutrient capture

Marine Biotechnology

Name of the Technology / Innovation: Seaweed nutrient capture

Sector: Marine biotechnology -First stage seaweed processing

Technology Readiness Levels (TRLs): TRL 6 – technology demonstrated in relevant environment

Country: Ireland


Using proprietary knowledge and working with local harvesters Redrose will process small quantities (1 or 2 tons daily) of various commercially valued seaweeds within a given geographical area – this would be assessed based on species and sustainability. Using only one ton at a time there would be two outputs after pre-treatment and processing. These would be a highly nutrient and mineral rich liquid and a carbon rich solid. Once stabilized the outputs would be quality validated and homogenized from a number of owner-operated franchise holders. The franchisee’s would operate the units under strict controls and protocols, with full training and support.

The harvesters would earn more revenue by adding value and taking only sustainable amounts of biomass from the wild harvest. The commercial return for the harvesters would attract other users to become owner-opeators and to operate under strict geographical limits. This would protect the wild harvest, processors would also process cultivated stock meeting the growing industrial needs for applications in various sectors: from food and feed to pharmaceutical and industrial.

The outputs would offer base material for further processing and through a number of units they would create appropriate scale without negatively impacting on the marine ecosystem. Protocols for processing, provenance and quality assurance would underpin the commercial agreement with both harvesters and customers providing reliable seaweed outputs and creating high quality employment for rural coastal communities.

The guarantee of purchase of stock would ensure that the franchise holders would earn enough money to recruit quality staff, pay licence fees and secure a healthy commercial return. Redrose would earn income from the franchise holders and the sale of the commodities generated.


Sustainability of the the wild harvested seaweed stock is a major concern as markets for seaweed continue to expand with global forecast sales of seaweed being in excess of $21b by 2022 . Although a small player in the global market, Irish seaweed is valued as a premium product due to the lack of industrial waste and the high levels of nutrients in pristine and cold Atlantic waters around the coast of Ireland. However, over 90% of sales of product using Irish seaweed comes from wild harvest. The most favoured harvested macroalgae is Ascophyllum Nodosum due to its high levels of nutrients and minerals.

But, this stock is not suited to cultivation as it takes 5 years to reach maturity to suit industrial needs. As markets continue to expand this once plentiful supply is being challenged. Cultivation costs are high due to the expense of infrastructure making the comparison of cultivated seaweed compared to that of wild harvested stock, in the region of 10x higher. The seaweed harvesters are an aging and declining population, with knowledge of key issues around sustainability, but, they are a valued resource that is fast disappearing. Due to the physical nature of the seaweed harvesting often in cold, wet shores cutting and lifting of wet weights often earning less than €60 per ton, the incentive and pressure from industry to cut ever increasing quantities puts the harvester at a disadvantage.

The Redrose option puts that harvester in control of his/her area of coastal conservation, whilst also rewarding them by creating higher value outputs. As owner-operators they are in control of their own destiny, but restricted to only processing 1 -2 tons per day to achieve a quality supply chain. The harvesters would earn more from using less biomass.


Redrose has secured two aquaculture licenses and has successfully cultivated Alaria, in Blacksod Bay in May 2020. Early trials are indicating good growth of Carrageen on the test site in Broadhaven Bay. The connection with a number of harvesters, two of which have signed a letter of intent to operating processing units with a 20 mile radius of Belmullet.

EU funding applications have been made under Blue Invest with EU partners from Holland, a soil conditioning consultant and fertiliser expert and a franchise expert to support the rolling out of the proposal. The application is supported by the Kering Group, who are keen to use algae based biopolymer to replace plastic in high end designer eye-wear.

Additional applications are being collated to apply for a BBI coatings fund supported by 4 EU partners from academia, SME’s with coordination and project management skills, and a ‘scaling up’ entity – this is supported by a major international paints manufacturer. Another project is working with three EU academic partners and a Solar Marine Engineering Company, Redrose seeks to develop a system for large scale, sustainable cultivation system to reduce the cost and risks of the growing seaweed in ‘At Sea’ sites. Redrose has secured limited investment, has been awarded a COST fund in 2020, and is currently involved in an acceleration program with PWC under ‘Blue Invest’.

This project will demonstrate that it is viable to create modest scale ‘first stage’ processing of the macroalgae within hours of being in the ocean. Benefiting from the retention of highly nutrient rich seawater in and around the seaweed. The pre-treatment of the seaweed will serve to breakdown the cell walls and release the minerals and nutrients into the liquid. The treatment of the liquid post separation will serve to stablise the stock prior to homogenization, quality validation will serve to provide a scalable biomass to suit industrial applications sustainably.


In the short term the finance to created the pilot scale model in Belmullet, is anticipated to cost iro: €45,000 This will provide outputs for industry specific tests. The medium term funding to create the full scale unit would be an investment of €264,000 – the additional two additional units would cost a further €500,000. To fully staff, to create the appropriate training and support packages for franchise units, to develop communication chains, work packages for product development with clients, to have continuous lab based quality assurance the anticipated investment sought, to have an appropriate marketing and sales strategy would be iro €2m.

Contact us on:


Corclough East, Belmullet, County Mayo

Contact telephone

00 353 873484269


Ann Ruddy