Mayo expert raises alarm over Clew Bay seaweed licence plan

Coastal architect and Helen McFadden says the BioAtlantis application proposes harvesting nearly 60,000 tonnes more seaweed than Clew Bay can sustainably produce and raises the alarm over flooding risk, worker feasibility, and the future of local harvesters, while the applicant, BioAtlantis re-affirmed their commitment to traditional seaweed harvesters.

A leading coastal architect has raised serious concerns about a proposal to harvest up to 11,018 wet tonnes of Ascophyllum nodosum seaweed from Clew Bay annually, warning that the ten-year licence application significantly exceeds what the bay can sustainably produce and could leave Mayo's coastline more vulnerable to flooding and erosion.

Helen McFadden, a coastal architect with expertise in shoreline ecology, has scrutinised the BioAtlantis licence application and found that the proposed extraction of approximately 104,144 wet tonnes over the licence period dwarfs the bay's estimated maximum sustainable yield of 64,759 tonnes, a shortfall of nearly 40,000 tonnes.

McFadden also raises the spectre of cumulative pressure on the bay's seaweed stocks. A 2014 Arramara Teoranta application proposed 5,275 tonnes annually from the same waters.

Should both licences be active simultaneously, the combined annual harvest would reach 16,293 tonnes, leaving just 307 tonnes for every other harvester along Mayo's entire coastline.

"Would two such large licences effectively squeeze local harvesters out of the sector?" McFadden asks. "Is too much of Mayo's seaweed harvesting being concentrated in Clew Bay? Should access be shared more broadly among multiple local harvesters?"

Another of McFadden's criticisms concerns the feasibility of the workforce plan.

According to an Irish EMFF socioeconomic study, hand harvesters typically collect between 100 and 200 wet tonnes annually, with intensive harvesters reaching a maximum of 500 tonnes.

The BioAtlantis application proposes achieving its 11,018-tonne annual target with just 16 full-time workers, a requirement of 688 tonnes per person, nearly 40 per cent above even the most intensive harvesting rate on record.

"The workforce and harvest volume claimed are not realistically achievable," McFadden concludes, "raising serious questions about feasibility."

The submission also highlights apparent inconsistencies in the application's documentation.

Mulranny Pier is referenced in parts of the paperwork but appears outside the red boundary on the maps, creating what McFadden describes as "confusion about the actual operational areas and harvest zones."

She further cautions that Mayo's piers and harbours are already in a fragile condition.

Hosting harvesting at the proposed scale could accelerate wear on critical infrastructure, interfering with maintenance schedules, emergency access, and day-to-day use by other coastal users.

Perhaps the most timely concern in McFadden's submission relates to coastal flood risk. With severe flooding having struck communities across Ireland in recent years, she argues that Ascophyllum nodosum plays an underappreciated role in protecting shorelines.

The species helps stabilise the foreshore, reduces erosion, and acts as a buffer against storm surges.

"Removing large amounts from Clew Bay could weaken these natural defences just when coastal communities are increasingly vulnerable," she warns.

In a statement, the Kerry-based firm said: “BioAtlantis wish to work in partnership with local hand harvesters in Clew Bay to create a vibrant industry, and add value to the seaweed resource in Ireland.

The application ensures that traditional seaweed harvesting rights are fully respected and measures are included to ensure the license has no impacts on existing harvesting rights in Clew Bay.

BioAtlantis will not harvest in any area where existing appurtenant rights exist, without first obtaining permission from the owner of such rights.

Where Profit-à-Prendre rights are successfully registered with Tailte Éireann, the harvesting plan will be adjusted to ensure that those individuals can continue to harvest.

It is envisaged that a clause may be included in the licence issued to allow the harvesting of Ascophyllum nodosum seaweed, stating that if a Profit-à-Prendre rights holder provides sufficient proof to their right, the licensee would be prohibited from harvesting in that area, without first obtaining permission from the owner of such rights.”