Wild-harvesting of the fucoid Fucus vesiculosus (Phaeophyceae) at an active oyster aquaculture site

The burgeoning interest in macroalgae as a sustainable resource across multiple industries – from agriculture and food to nutraceuticals – is gaining significant traction, and this recent study on *Fucus vesiculosus* harvesting at Irish oyster farms adds a valuable data point to that narrative. While aquaculture currently dominates global seaweed biomass production, the continued importance of wild-harvesting, particularly in Europe, necessitates innovative approaches to resource management. This research builds upon earlier explorations of integrating diverse marine resources, as exemplified by the work on forecasting coastal temperatures for aquaculture operations [Multi-horizon forecasting of coastal high water temperature events for operational marine-heatwave early warning in South Korean aquaculture: a walk-forward benchmark of eleven statistical and deep-learning models] and the investigation of by-products like grape marc to enhance fish health and resilience [From by-product to benefit: the effect of white grape marc extracts on European seabass growth, gut microbiota, immune status, and resistance to Vibrio harveyi]. The potential to leverage existing infrastructure – oyster farms – to sustainably yield valuable biomass represents a compelling opportunity for both shellfish farmers and the broader bioeconomy.

The core finding that low-intensity partial harvesting of *F. vesiculosus* can be sustainable, with regrowth rates reaching up to 87% within a year, is particularly noteworthy. The study’s rigorous methodology, including quantification of biomass yield and regeneration under different cutting treatments, provides a robust foundation for future development. Estimating a potential harvest of approximately 11 tonnes of biomass from a 1 km stretch of shoreline using the “Cut S” treatment highlights the scale of this largely untapped resource. This research echoes the broader call for integrating scientific understanding into marine resource management, as discussed in recent analyses of fisheries, aquaculture, and living resources [The future of our oceans: negotiating marine fisheries, aquaculture, and living resources with unbiased science]. The non-linear seasonal growth patterns observed further emphasize the need for adaptive management strategies that account for environmental variability.

The concept of co-locating *Fucus* crops with oyster aquaculture – a "proof-of-concept" demonstrated by this study – is a significant advancement. It moves beyond simply identifying a resource and explores the practical integration of seaweed cultivation into existing aquaculture practices. This approach aligns with the principles of circular economy and sustainable intensification, maximizing the value derived from marine environments while minimizing ecological impact. The validated methodology presented here—measuring regrowth rates, quantifying biomass yield, and calibrating harvesting strategies—offers a template for similar investigations at other coastal sites. The longitudinal data collected over a 12-month period provides empirical evidence supporting the feasibility of this approach and strengthens its credibility within the scientific community.

Looking ahead, the success of this study raises important questions about the broader potential for integrating wild-harvesting and aquaculture practices. Can this model be replicated across different seaweed species and geographical locations? What are the economic incentives for shellfish farmers to adopt these integrated approaches, and how can policy support these transitions? Further research should focus on optimizing harvesting strategies to maximize biomass yield while ensuring long-term ecological sustainability, as well as exploring the potential for utilizing the harvested *Fucus* biomass in various value-added applications. The intersection of sustainable aquaculture and responsible resource utilization is a critical area for continued investigation, and this work offers a promising step towards a more integrated and resilient ocean economy.