All-Atlantic 2021:
Sargassum side event

Once confined to the Sargasso Sea, thousands of tons of Sargassum now make their way to beaches in the Caribbean, East Americas, and West Africa. Sargassum is a genus of large brown algae, with two species in the Atlantic found in free-floating mats, held afloat by gas-filled bladders. These rafts serve as a critical habitat for threatened loggerhead sea turtles and as a nursery shelter for a variety of commercially important fishes such as mahi-mahi, jacks, and amberjacks. In 2011, floating Sargassum began to impact coastal communities around the tropical Atlantic Ocean. Washed up Sargassum rots, attracts flies, deters tourists and causes respiratory problems due to release of hydrogen sulphide and ammonia. Floating mats and mounds near beaches harm marine ecosystems and disrupt recreation, tourism and fishing, costing local communities millions of dollars.  

On-going research efforts and developments are led to understand the mechanisms behind its basin-wide spread, its impact on both marine life and local communities as well as providing solutions for mitigation and beyond. This is a social, economic, and ecological challenge that requires a multi-disciplinary approach. In this context, the Sargassum hub (https://sargassumhub.org/) launched in 2020 serves as a single–entry point to access information and tools for the monitoring and management of sargassum blooms for all stakeholders from scientists to local fishermen. The Sargassum Hub is developed by the GEO Blue Planet Initiative, in collaboration with IOCARIBE of IOC-UNESCO, AtlantOS, the Atlantic International Research (AIR) Center and other partners. The side event will also be the opportunity for UNEP Cartagena Convention to launch their white paper compiling background information for a strategic status update and critical situational analysis that informs and elicits feedback from key regional stakeholders. It focuses on influxes in the Caribbean, with reference to other impacted regions as appropriate. 

This side event presented and discussed challenges, solutions and opportunities behind the spread of Sargassum across the Tropical Atlantic. Experts presented challenges and state-of-the-art research on the spread mechanisms, various impacts and the present capacity of monitoring and forecasting. The event showcased solution strategies and created a space for discussion and collaboration between scientists, engineers and stakeholders, providing insight into the opportunities for addressing the Sargassum problem across the Atlantic Ocean.