Seaweed and kelp will probably be a much larger source for both human and animal diets, as well as raw materials in other industries Seaweed solutions

Seaweed cultivation is becoming a major industry. Are we prepared?

NORWAY
Wednesday, November 25, 2020, 06:10 (GMT + 9)

A sharp upscaling of the kelp industry is probably on the steps along the Norwegian coast. Then it is important to understand the rules of the ecosystem.

The Norwegian coast is long, with cold, nutrient-rich water that is well suited for kelp cultivation. In 2018, kelp production in cultivation facilities in Norway was 178 tonnes. But already in 2050, production is estimated to be around 20 million tonnes . With our long coastline, it is safe to say that the potential for cultivation is enormous.

Seaweed will probably be an important source of food and other products in the future. We already see that the kelp industry is being scaled up for food, animal and fish feed production. A lot of exciting things are going on with regard to the extraction of raw materials that can replace plastic in packaging, among other things.

NIVA researcher Kasper Hancke is one of those investigating this. Photo: NIVA ►

In the future, it is easy to imagine that kelp can be processed into a number of different raw materials, for example as building blocks in the chemical industry, and that the remaining biomass is fermented into biogas in combination with carbon capture and storage technology (CCS).

Blue forest with a green future

Along the Norwegian coast we find natural kelp forests that cover an area corresponding to Norway's cultivated agricultural area. The kelp forest constitutes important ecosystems and forms the basis for a rich food network of small animals and fish. It also secures nursery areas for commercial fish species and shellfish.

Today, about 160,000 tonnes of kelp are extracted from these kelp forests every year. This is a strain on coastal ecosystems in the affected areas, and it takes years before it recovers.

Seaweed is fast-growing and can be sown on ropes placed in the sea in autumn. Up to ten kilos of kelp per meters of rope can be harvested already during early summer. (Photo: NIVA)

By growing kelp, we can preserve the natural kelp forest and at the same time increase resource harvesting of kelp biomass for industrial purposes.

Seaweed is fast-growing and can be sown on ropes placed in the sea in autumn. Up to ten kilos of kelp per meters of rope can be harvested already during early summer. During this short period, up to 200 tonnes per year can be produced. hectares pr. year. The rapid production of biomass takes place without the use of either fertilizers or pesticides.

All that is needed are natural nutrients, CO₂ and solar energy.

As kelp grows, it absorbs CO₂. Thus, it can potentially contribute to CO₂ reduction - up to 25 tonnes of CO₂ per. hectares. In this way, kelp cultivation can contribute as a measure against climate change and as an important piece in a rapid transition to a green future in resource production - both in Norway and internationally.

NIVA researcher Hartvig Christie has assessed both positive and negative environmental impacts of kelp cultivation (Photo: NIVA)

Sustainable production

With a possible kelp growing revolution just around the corner, it is important to prepare both us and marine ecosystems for what awaits. The Government's marine strategy from 2019 will facilitate further growth in the seafood industry within a sustainable framework. In the NIVA-led KELPPRO project , funded by the Research Council of Norway, the researchers have assessed both positive and negative environmental impacts of kelp cultivation.

The environmental footprint of kelp cultivation is probably small. Yes, in fact, a kelp plant can contribute to more positive ecosystem services. In addition to producing biomass and absorbing CO from the atmosphere, CO uptake will also reduce the risk of ocean acidification. In addition, kelp cultivation will absorb nutrients from the water masses, which can reduce the negative consequences of over-fertilization where this is a problem.

By understanding the ecosystem's rules of the game, and with a solid foundation in competence and experience through many years of research on natural kelp ecosystems, a sustainable development of the kelp farming industry can be ensured.

Photo: NIVA

Possible negative effects

Large-scale kelp cultivation can have negative effects on the marine environment. Large amounts of kelp biomass that ends up on the seabed, either by accident in production or by proven location, can lead to lack of oxygen, change in biodiversity and poor ecological condition on the seabed. And large uptake of nutrients will be able to outcompete natural seaweed, kelp and algae growth in the sea. This in turn can affect the basis of the food chain, the fish stocks - and then ultimately us humans.

Whether kelp facilities contribute to the undesired spread of species, genes and any diseases in the sea is currently largely unknown. However, recent results from the KELPPRO project indicate that alien, unwanted species can utilize kelp cultivation plants outside the growing season as well.

Such studies are crucial to ensure the long-term, sustainable development of the industry, both ecologically and economically. Perhaps a research-based administration will be able to save the kelp industry many of the challenges that the fish farming industry has had to fight against?

Seaweed on the go

Developments today open up exciting opportunities in the kelp cultivation industry. At the same time, it is important to be aware that the facilities' impact on the environment has been little studied. In order to conduct kelp cultivation in an ecologically and economically sustainable way, it is important to ensure an even better understanding of the ecosystem's rules of the game.

We who work with research on seaweed and kelp, believe that kelp cultivation and algae-based production can be developed into a blue resource with a green future. Everything indicates that kelp is on the way, both in this country and elsewhere in the world.

Authors:

Hartvig Christiesenior researcher, Norwegian Institute for Water Research (NIVA)

Kasper Hanckesenior researcher, Norwegian Institute for Water Research (NIVA)

(translated from original in norwegian)

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