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The green transition can also be blue

In a new report, blue biomass is the term for resources from the sea, which we can exploit much more sustainably both on the dinner table and as tool for environmental restoration. Still, the report concludes, green transition towards increased use of blue biomass such as seaweeds and mussels calls for the will and ability to solve challenges if we are to succeed.

[Translate to English:] Sukkertang produceret ved Aarhus Universitets dyrkningsanlæg ved Grenå. Foto: Teis Boderskov (Aarhus Universitet, Institut for Bioscience).

The world's population is expected to reach 9.8 billion people by 2050. Both globally and nationally, there is a strong focus on the need to restructure food production to increase public health and reduce the negative impact on the environment and climate.

In both contexts, increased production of food from the sea can be part of the solution. This is the conclusion of a new report by DTU Aqua and Aarhus University, prepared at the request of the Ministry of Food, Agriculture and Fisheries of Denmark, which emphasizes that blue bioeconomy can support the green transition.

The report, which is in Danish and entitled “Vidensyntese om blå biomasse” (in English: "Knowledge synthesis on blue biomass"), deals with society’s ability to meet the future demands for a more climate-friendly and sustainable food production through transition to food from the sea.

Read the report ”Vidensyntese om Blå Biomasse” (in Danish only)

In Denmark, we traditionally have meat, cereals and quota fish on the dinner table - three headings for a food production that puts a pressure on our environment, not least in the form of discharging nutrients to the sea or affecting the seabed with bottom trawling fishing equipment.

But the sea around Denmark has something else to offer. The equally healthy and untapped alternative comes in various forms of blue biomass, and the report includes "all organic material extracted from the sea, minus quota-covered and farmed fish".

Senior Researcher Annette Bruhn from the Department of Bioscience at Aarhus University, who is co-author of the new knowledge synthesis, says:

- Seaweeds such as sugar kelp, sea lettuce and dulse are good examples of blue biomasses that can be produced at a much higher scale in Danish waters. The same goes for shellfish like blue mussels, common cockles, razor shells and oysters.

- And the Danish coastal waters are particularly suitable for producing seaweeds and mussels due to its salinity, purity and moderate exposure to currents and waves. In Denmark, we have been producing sugar kelp since 2008, and research and development are reaching a point where are scaling up production. Sugar kelp is used as an ingredient in Nordic seaweed salad and pesto, among other things, but there are great prospects for the use of seaweeds in both plant-based foods and more climate-friendly animal feed.

Water-purifying seaweeds and mussels

Blue biomass can do more than provide good supplements of omega3 fatty acids and proteins. Seaweeds and shellfish also have the ability to function as biological emission capture and utilization technologies as they capture dissolved CO2 from the atmosphere and nutrient emissions from land.

Professor Marianne Thomsen from the Department of Environmental Science at Aarhus University, who is also co-authoring the knowledge synthesis, says:

- By growing seaweeds and mussels, the nutrients are built in valuable biological material, which can be brought back to the food chain on land in the form of healthy food and feed. It is pure circular bioeconomy.

Future prospects for blue bioeconomy

However, transition to the application of blue biomass calls for new cultivation technologies and processing methods. It requires more skills and new knowledge, and cultivation licenses aligned with Marine Spatial Planning. Not least, the transition depends on the willingness of the consumers to embrace the new products.

- There is no doubt that it will also require a change in consumer behavior to introduce more seaweed and mussels on the dinner tables in Denmark, but my impression is that there is a significant curiosity about new Nordic ingredients as well as a great ambition to eat more climate-friendly food, says Annette Bruhn.

The researchers behind the report identify a number of solutions that could boost the blue bioeconomy. Seaweed and shellfish farmers could be rewarded subsidies in the form of payment for the ecosystem services, such as the uptake and removal of nutrients by mussels and seaweed, and the CO2 that seaweeds absorb from the atmosphere.

But according to the researchers behind the report, a green transition to a blue bioeconomy requires political support:

“A visionary political approach to sustainable production of blue biomass will support global, European and national strategies and directives across resource production, climate and marine environment. This will help bringing Denmark in a lead position on sustainable technologies with potential for distribution and export to the rest of the world”, the report concludes.

Additional information

We strive to ensure that all our articles live up to the Danish universities' principles for good research communication (scroll down to find the English version on the website). Because of this, the article will be supplemented with the following information
FundingThe report is funded by the Ministry of Food, Agriculture and Fisheries of Denmark.
Collaboration partnersDTU Aqua, Technical University of Denmark, DCE - Danish Centre For Environment And Energy, Aarhus University and Aarhus University Centre for Circular Bioeconomy, Aarhus University. 
Read more

Read more in the report ”Vidensyntese om blå biomasse” (Danish only), DTU Aqua-rapport no. 387-2021, on this link.)

Background for the report:
In 2016, the National Bioeconomy Panel recommended that a knowledge synthesis on blue biomass should be prepared, based on an update of the knowledge synthesis from 2010 called “Havet – en uudnyttet resource (in English: “The sea - an untapped resource” (Ministry of Food, Agriculture and Fisheries of Denmark 2010). The panel was revised and restarted in a new form in 2017. In 2018, the revised bioeconomy panel recommended, as part of their protein recommendations, that research and development efforts should be implemented to uncover both the socio-economic and business economic potentials for catching and producing new aquatic protein sources, including seaweed and algae. In 2016, DTU Aqua prepared a report on mussels and seaweed, which was used as a background document for the bioeconomy panel's recommendations the same year.

“Vidensyntese om blå biomasse“ (in English: "Knowledge synthesis about blue biomass") is a result of a request for a knowledge synthesis initiated by the Office for Sustainable Fisheries in the Ministry of Food, Agriculture and Fisheries of Denmark, to follow up the Agency's objective of increased research-based documentation in the field.    

ContactAnnette Bruhn, Senior Researcher, Department of Bioscience – Marine ecology, anbr@bios.au.dk, phone: +45 29638034 Marianne Thomsen, Professor, Department of Environmental Science - Microbial Ecology and Circular Resource Streams, mth@envs.au.dk, phone: +45 22292627