Assessing the interconnectivity across complex dimensions of monitoring pelagic species of Sargassum and the role of citizen science

Abstract

The mass accumulation of pelagic species of the genus Sargassum (referred to as sargassum) on coastlines is a pressing socio-environmental issue that spans the tropical Atlantic region. Since the unprecedented increase in biomass in 2011, innovative monitoring approaches have emerged to track sargassum across varying spatial and temporal scales, including satellite imagery, aerial imagery, citizen science, and traditional in situ evaluations of biomass. This study systematically reviewed peer-reviewed literature (2011–2024), gray literature, and open science sources to assess the methodologies used to monitor sargassum. Conversations with select experts involved in established monitoring programs, often tailored to end users such as government agencies or local communities, provided additional insight into the multidimensional nature of monitoring strategies. We found that while satellite imagery is commonly paired with in situ biomass evaluations in the literature, citizen science is emerging as a scalable, accessible tool to fill spatial and temporal gaps, despite limited representation in scientific publications. Aerial imagery is frequently mentioned as a promising supplement to both satellite and citizen science efforts, but its practical use remains limited. Field-based estimations remain the most direct method to quantify biomass but are constrained by spatial scale, funding, personnel, and feasibility for long-term monitoring. This review highlights the need for improved collaboration and data sharing across programs and scales, and creating platforms to return information to users. Strengthening connections among all involved in the design, participation, and use of community-based monitoring products, including a stronger relationship and clear benefits, will be essential to provide continuity and improve management strategies for this evolving environmental phenomenon.