First seaweed harvest completed at North Sea farm located among wind turbines

The first harvest has been completed at North Sea Farm 1, a seaweed cultivation project located within an offshore wind farm in the North Sea. The site, situated around 18 kilometres off the Dutch coast near Scheveningen, is described by its developers as the first commercial-scale seaweed farm of its kind.

Operated by Netherlands-based non-profit group North Sea Farmers, the initiative has received €2 million from Amazon’s Right Now Climate Fund, a $100 million programme supporting projects focused on climate and biodiversity.

According to North Sea Farmers, placing the farm within the Hollandse Kust Zuid wind park allows it to make use of otherwise restricted marine space, shielded from shipping routes. The farm covers five hectares and uses large nets anchored to the seabed, from which seaweed is harvested using specialised vessels that navigate between the wind turbines.

The project began development in 2022, with planting starting in October 2024.

Eef Brouwers, Managing Director of North Sea Farmers, said in a press release that the project demonstrates “seaweed production within an existing offshore infrastructure is possible at a commercial scale”. He added that the organisation is aiming to evaluate the farm’s long-term effects on biodiversity and its potential role in mitigating climate change.

Amazon Netherlands and Belgium country manager Eva Faict called the harvest a "significant moment". "Together with North Sea Farmers, we have proven that cultivated seaweed farming among offshore wind turbines is a viable commercial concept," she said.

Researchers from Plymouth Marine Laboratory, Deltares and Silvestrum Climate Associates have been monitoring the site for the past year. They plan to assess the seaweed’s carbon uptake, growth patterns and any ecological changes to the surrounding environment. The data, NSF says, will help to establish "upper scaling limits" for future seaweed farming projects between offshore wind turbines.

“We’re very excited to understand the effects of the seaweed farm on the immediate and surrounding marine environment. Our analysis will follow the carbon from the seawater into the seaweed and the environment, and any effects on biodiversity," said Plymouth Marine Laboratory’s Professor Ana M Queirós.

"We will be taking seabed samples, water samples and in-situ monitoring of marine life and the use of advanced eDNA techniques to gain a detailed understanding of the developing habitat and the various species it may or may not be supporting."

"It’s vital projects like this are underpinned with rigorous scientific evidence, particularly given the urgency of the climate and biodiversity crisis and the need to find scalable mitigation measures that produce genuinely beneficial and sustainable outcomes," Quierós explained.

North Sea Farmers say the harvested seaweed may be processed into a variety of products, including food, textiles and wellness goods.

"In general, because seaweed does not require land, fresh water, or fertilisers to grow, and it can be used to replace a number of materials traditionally farmed using chemicals on land," NSF stated.