Socio-ecological vulnerability assessment to Sargassum arrivals

Area of Science:

• Marine biology
• Oceanography
• Environmental science

Background:

• Holopelagic Sargassum spp. blooms in the tropical North Atlantic pose significant threats to coastal ecosystems and populations.
• Satellite data estimates seasonal Sargassum biomass at 10-20 million tons, but coastal accumulation remains unquantified.

Purpose of the Study:

• To quantify Sargassum stranding on coasts and develop vulnerability indicators.
• To assess the risks of Sargassum influxes on coastal regions by integrating biomass, ecosystem, and socioeconomic factors.

Main Methods:

• Combined satellite data with an algal growth-transport-stranding model to estimate coastal Sargassum accumulation.
• Developed novel vulnerability indicators integrating stranded biomass, ecosystem, and socioeconomic data.

Main Results:

• Coastal Sargassum accumulation is approximately 10% of offshore biomass, totaling 2-10 million tons annually over the past five years.
• The Mexican Caribbean, northern Lesser Antilles, and eastern Great Antilles are identified as highly vulnerable regions.

Conclusions:

• Sargassum influxes present substantial ecosystemic and socioeconomic challenges to vulnerable coastal areas.
• Quantifying stranded Sargassum and assessing regional vulnerability are crucial for effective coastal management.