Six rimurimu/seaweed species could put Aotearoa New Zealand on the map

1 November 2021

Story republished with permission from Sustainable Seas National Science Challenge

Rimurimu/seaweed should be a natural contributor to Aotearoa New Zealand’s blue economy because there is a wealth of diversity of species growing along our coastlines.

Previous research from our Building a seaweed sector project shows our country could gain huge benefits, the seaweed sector is still in its infancy as New Zealand currently only harvests wild seaweed.

According to two new reports from the research team, developing aquaculture farms using an ecosystem-based management (EBM) approach and with co-ordination between industry, iwi/hapū and regulators could grow Aotearoa New Zealand’s seaweed sector safely, significantly and effectively.

The Species characteristics and Te Tiriti o Waitangi considerations report has reviewed six seaweed species groups identified for commercial development: karengo, Asparagopsis, agarophytes, lamanarians, fucoids and green algae.

“Our species are generally underdeveloped in regard to their commercial potential and there is an opportunity to produce and sell seaweed products that are different from those in other parts of the world,” said Serean Adams, Project Leader of Building a seaweed sector and Aquaculture Group Manager at Cawthron Institute.

But targeting high-value markets requires specific information on each species.

“Current knowledge of seaweed species is mostly focused on their ecology. Information about the biology and how to cultivate the species is sparse and scattered through scientific literature. This makes it difficult for those interested in developing a seaweed sector to access.”

That’s why the research suggests one approach may be to build from our already existing bio stimulant and fertiliser market. These markets could then be used as a platform to move into higher value products. For example, extracts as functional foods, food ingredients and health supplements or cosmeceuticals.

Cawthron-AQ-Seaweed
Image: Unsplash
Serean Adams

Serean Adams

Aquaculture Group Manager

The report helps highlight the cultural importance of seaweed species to Māori and to support the role of Māori kaitiaki rights in the emerging seaweed sector.

“Māori have a particularly unique whakapapa relationship with flora and fauna and we need to acknowledge and respect that in the process of developing this sector,” said Andy Elliot, Research and Business Development Manager from Wakatū Incorporation, a whānau-owned organisation involved in seaweed research.

“For example, karengo is considered a taonga.”

Practical experience in growing, processing and marketing seaweeds and seaweed products in Aotearoa New Zealand is limited. This could be an opportunity for iwi/hapū to be supported to create sustainable seaweed businesses founded on their vision and values.

The other report, Environmental effects of seaweed wild-harvest and aquaculture, recognises why an EBM framework is vital. There may also be potential for seaweed farming to improve ecosystems because seaweed can help with nutrient removal, shoreline protection, regenerative opportunities, and offers the potential for carbon sequestration.

However, this report shows that many of the benefits (and risks) are site and scale specific, and there is associated uncertainty as a result.

“No matter what species are chosen, the development of commercially-viable farming systems is probably the most pressing hurdle to overcome,” explains Dr Adams.

“This can be best achieved through leveraging overseas expertise, and by ensuring that knowledge generated through Aotearoa New Zealand research is publicly accessible. This enables farmers to ‘give it a go’ using approaches that are appropriate for the Aotearoa New Zealand situation.”

The time is right for Aotearoa New Zealand to take advantage of this growing industry and expand our budding seaweed sector by using the suitability of our environment for seaweed aquaculture.

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