Aquaculture: Global seaweed expert to share blue carbon opportunities for New Zealand

Not-for-profit organisation Greenwave Aotearoa's seaweed growing trial in the Hauraki Gulf.

A global seaweed expert says New Zealand has the opportunity to regenerate and repopulate not only the marine ecosystem but also its remote towns through seaweed aquaculture.

Peter Green is being brought to New Zealand from the United Kingdom in October with Auckland-based environmental impact investment project developer EnviroStrat, which is enabling a new generation of seaweed entrepreneurs in Aotearoa.

Green, based in the United Kingdom, is a seaweed project manager and adviser at Hatch Blue, and the author of a widely-read algae newsletter, the Paxtier Report.

At Hatch Blue, he regularly advises investors on seaweed opportunities and has developed several key initiatives, including The World Bank’s Global Seaweed New and Emerging Markets Report 2023.

His tour with EnviroStrat will connect New Zealand’s aquaculture industry, seaweed researchers, environmental policymakers and potential investors dedicated to advancing sustainable blue economy solutions.

EnviroStrat is developing seaweed aquaculture in New Zealand through Greenwave Aotearoa, a multi-year seaweed farming proof of concept, in collaboration with iwi, marine farmers, scientists, seaweed product manufacturers, and investors.

Green will present on the global market in blue carbon and new projects, presenting case studies from Japan focusing on the certification of blue carbon projects and the issuance of J-Blue Creditsor Blue Carbon, in Japan.

“We’ll explore the role of blue carbon and discuss its potential impact and relevance for New Zealand, as well as delve into Japan’s innovative approaches to incorporating wild seaweed and seagrasses into their national carbon calculations,” Green said.

Japan recently decided to factor the carbon sequestration of wild seaweed and seagrasses into its national emissions calculations.

It was believed to be the first instance where a country has included national seaweed CO2 absorption in Greenhouse Gas Inventory Reports submitted to the United Nations.

“This advancement has captured international attention and set a new standard for blue carbon market methodologies,” Green said.

He said the next generation of aquaculture was moving toward a more sustainable approach, and emphasised an important difference between wild and farmed seaweed in the blue carbon space and concepts of regenerative seaweed aquaculture.

“At every conference I go to, we start to talk about one ocean, that it’s a shared ocean.

Peter Green, seaweed project manager and adviser at Hatch Blue, is coming to New Zealand in October.

“There are many facets to it, but in a broad sense, you’re using aquaculture to produce the most sustainable food and products on the planet, and in doing so, you don’t destroy or degrade the environment in any way.

“You only support its flourishing.”

Principles of regenerative seaweed aquaculture include using native species only and, where possible, diversity within farming sites should be maximised, for example, combining multiple seaweed and/or other low-trophic species.

Green said management of a farm should also include monitoring and evaluating local community attitudes.

“Very important for New Zealand going forward is making sure you give communities the chance to create value chains close to where they are,” he said.

“In the case of seaweed, this is the importance of the work through Greenwave Aotearoa.”

Green said the benefit of farming seaweed could be seen in remote regions of the UK and Ireland, where young people tended to move away.

“If you can keep some bright minds in those areas, we do see the potential to re-energise and repopulate these towns.”

EnviroStrat founder Nigel Bradly was one of the first people interviewed for Green’s podcast in 2018 when Green began his popular global seaweed market The Paxtier Report.

Bradly said seaweed aquaculture was in its infancy in New Zealand, underpinning the importance of Greenwave Aotearoa trialling hatcheries and techniques for farming native species.

In doing so, it supported seaweed farming’s establishment and growth through collaboration with funders, iwi and seaweed product manufacturers.

“Without a strong supply chain from farmed product, the seaweed sector will remain constrained in New Zealand,” he said.

New Zealand has relatively similar coastal ecosystems to Japan, with kelp beds and mangrove forests.

Yet there remain multiple challenges in scaling seaweed aquaculture here, with catalytic investment among them.

Bradly said: “By bringing Peter to our shores, we can showcase global expertise in both seaweed markets and practices, and gain valuable insights into the emergence of blue carbon methodologies that could potentially be adapted here.”

Green believed New Zealand’s productive ocean waters and its reputation as an environmentally forward-thinking nation positioned it well to set a pathway for a thriving seaweed aquaculture sector.

“Globally, we recognise that New Zealand has great branding power and potential, and highly productive waters.

“Technology is needed where costs are high for labour, so yes, there’s ample room for New Zealand to set a pathway for seaweed aquaculture growth.”

In New Zealand, the terms restorative and regenerative aquaculture may be new to mainstream audiences.

However, studies suggest restorative aquaculture can simultaneously improve the health of aquatic environments and provide food for a growing population.

Green said investors were increasingly interested in aquaculture developments that reintroduced biodiversity, reduced impacts of climate change, and improved water quality, rather than mass production of a single protein species with little or no environmental benefit.

He gave examples of fin fish farming being offset by establishing a neighbouring farm in seaweed.

“More broadly with restorative aquaculture, it might be how we restore an area,” he said.

He used the example of shrimp ponds, which have significantly impacted the degradation of mangrove forests.

“It’s possible to counter this destruction by repopulating the shrimp ponds with mangroves, which in some instances can boost productivity for remote farming communities, reduce farming area and regenerate productive blue carbon ecosystems.

“It’s about being more holistic in our working with the ocean.”

The EnviroStrat and Greenwave Aotearoa tour with Peter Green is in October - register for interest to hear him speak at info@greenwave.nz.