POSTER SESSION 4
10:30–12:30, Thursday, September 17
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1294 | POSTER 124
LONG-TERM SHIFTS IN PELAGIC SARGASSUM COVER IN THE MEXICAN CARIBBEAN: AN ASSESSMENT OF DURATION AND RELATIVE INTENSITY USING OCEAN COLOR SATELLITE DATA
A continuous monthly time series of relative surface Sargassum cover was developed for the Mexican Caribbean by integrating satellite products from the Sargassum Watch System (SaWS) and Copernicus Sentinel-3 NFAI detections. A homogenization procedure ensured consistency between sources, producing a record spanning 2010–2026. After excluding observations with >80% missing data, Sargassum events were identified using monthly climatological anomalies and a fixed threshold. Events were defined as consecutive periods exceeding this threshold with positive anomalies. Event duration was computed in months, and intensity was expressed relative to climatology as the ratio between observed Sargassum cover and the corresponding monthly mean. Results reveal a pronounced regime shift in regional Sargassum occurrence. No persistent events occurred during 2010–2013. Between 2014 and 2017, two short events (~6 months) exhibited near-climatological intensity (1.3–1.4x). From 2018 to 2024, six events were identified, lasting 3–11 months with increased intensity (1.0–1.9x climatology). Post-2018 events also show greater persistence (6–9 months on average). The 2025 event displays the highest intensity in the record (~4.1x climatology) and extended duration (~8 months), while an early-onset and intense 2026 event is ongoing. Overall, the system transitions from shorter, near-climatological events to longer and more intense occurrences after 2018. This framework based on duration and relative intensity characterizes the non-stationary behavior of pelagic Sargassum in the Mexican Caribbean, with implications for coastal exposure and ecosystem pressure. Seasonal wind variability may modulate local accumulation, although no clear interannual relationship is observed, suggesting a dominant role of large-scale production and transport processes.
Julio Lara Hernandez, University of Victoria, [email protected]
Nelson de Almeida Gouveia, University of Victoria, [email protected]
Santiago Ramirez Said, University of Victoria, [email protected]
Maycira Costa, University of Victoria, [email protected]
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
