• Mogensen, Lisbeth
• Waqas, Muhammad Ahmed
• Knudsen, Marie Trydeman
• Hashemi, Fatemeh

Abstract

<p>This study provides a comprehensive review of the environmental impacts associated with seaweed cultivation and utilization in various industries, focusing on life cycle assessment (LCA) studies. There is a remarkable disparity in the distribution of LCA studies. Asia produces 97 % of the global seaweed, but accounts for only 25 % of LCA research. In contrast, Europe, which produces only 0.8 % of the global seaweed production, is responsible for 70 % of the studies. Current cultivation practices result in low emissions of 0.02–0.08 CO₂-equivalents (CO₂ eq)/kg of wet seaweed. Cultivation may yield climate benefits if biogenic carbon uptake and sequestration are considered. However, the stability of the stored carbon requires further research. Seaweeds have significant potential in various sectors, including bioenergy, food, feed, fertilizer, nanomaterials, construction, and cosmetics, supporting a circular bioeconomy. However, environmental hotspots include energy use for drying, fuel for transport, infrastructure production, and the processing phase. Various mitigation strategies include recirculation and utilization of by-products, extending infrastructure life, recycling infrastructure, using biodegradable materials, adopting renewable energy for drying, optimizing seaweed productivity and the content of valuable ingredients, refining system design for resource efficiency, developing biorefineries, and investigating alternative seaweed species. The diverse functional units used in LCAs limit comparisons between studies. Challenges in seaweed LCA research include the lack of standardized methodologies for varied production systems, cultivation impacts on local ecosystems, data limitations, and often comparisons of seaweed to terrestrial alternatives. Seaweed has the potential to promote sustainability in certain sectors. However, further research is needed to optimize seaweeds as a sustainable resource.</p>

Topics

• impedance spectroscopy
• Carbon
• phase
• drying