Pelagic Sargassum spp. blooms pose a complex challenge to the Caribbean coast, affecting ecological, economic, and social dimensions. Since the formation of the Great Atlantic Sargassum Belt in 2011, these blooms have become an annual occurrence, lasting up to nine months each year. The Sargassum that washes ashore in the Western and Central Caribbean can reach tens of thousands of cubic meters per kilometer annually. These algae can carry pollutants, pathogens, and exotic species to coastal zones. As the algae decay, toxic gases and leachates are released, posing significant health risks to humans and other species. Ecologically, Sargassum landings contribute to beach erosion, nearshore waters eutrophication and transition from sandy to muddy sediments, and oxygen depletion, leading to losses in seagrass meadows flora and fauna. Mangrove ecosystems, inlets, and bays face disruptions in their biochemistry, hydrodynamics, and ecology, potentially shifting from carbon sinks to sources of greenhouse gases. Economically, the impact is severe, threatening the tourism and fishing industries crucial to the affected countries' economies. Socially, the blooms affect various aspects of well-being, including health, job quality, and connections to nature. Although progress has been made in understanding the impacts of Sargassum, much of the research has been concentrated in Mexico, primarily focusing on the ecological effects on coastal and beach environments. However, considerable knowledge gaps remain regarding the impacts of Sargassum on the ecosystems, economies, and social well-being of many other countries and territories in the region.

This study collates and reviews the state of the art in the phenomenon of atypical pelagic Sargassum influxes in the coastline of the Mexican Caribbean, focusing on projects, studies and initiatives that have been conducted in the country for a decade. We integrated multisectoral and multidisciplinary knowledge and identified gaps and strengths in current knowledge. Initiatives and projects conducted in Mexico are numerous, diverse and valuable. However, interdisciplinary and transdisciplinary research and interinstitutional coordinated actions in the medium- and long-term are still lacking. Because of this, there is an imbalance of actions in different knowledge areas that prevents this phenomenon from being addressed in a comprehensive way. Furthermore, the funding opportunities for Sargassum research projects and other initiatives seem to respond to the events of massive influxes, without continuity or long-term planning. Attention is mainly focused on urban and touristic areas, so impacts to rural or uninhabited zones are unknown. This review represents a stepping-stone towards an integrated multisectoral effort to shift the perspective from Sargassum being a “national problem” to a “national resource,” considering and fully understanding the ecological importance of this macroalgae as a floating ecosystem and its potential as an economic resource once it massively arrives in Mexican coastal areas.

The spatiotemporal variation of the distribution of echinoderms in the Georges Bank ecosystem was examined from 2005 to 2012. Density and abundance of representatives from echinoderm classes (brittle stars, sand dollars, sea stars, and sea urchins) were estimated using a drop camera video survey of the benthos in areas open and closed to fish trawling. The influence of closed areas on these echinoderm populations relative to a suite of key environmental and biotic factors was evaluated using Canonical Correspondence Analysis (CCA). While marine protected areas appeared to influence the distribution of sand dollars and sea stars, the distribution of brittle stars and sea urchins seemed to be defined mainly by preferred habitat conditions. According to the CCA, depth, sediment stability, temperature, predator abundance, and management area were the most important factors explaining this echinoderm assemblage. On Georges Bank, echinoderms dominate the benthic biota and are present in a variety of habitats. They can alter marine communities and are preferred prey and main predators for several commercially targeted species. The detailed information presented here (on the scale of kilometers) on abundance and spatial distribution of these populations is thus valuable towards the implementation of ecosystem‐based fisheries management.