POSTER SESSION 3
15:30–17:30, Wednesday, September 16
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1184 | POSTER 59
CLIMATE CHANGE IN THE PATAGONIAN SHELF FAVORS DIATOM DOMINANCE
The Patagonian Shelf, located in the Southwestern Atlantic Ocean, is among the most biologically productive regions worldwide, owing to its extensive phytoplankton blooms, and constitutes a major global carbon sink; however, phytoplankton biomass in this region is already exhibiting climate-driven changes. Here, we quantify shifts in phytoplankton assemblages using 26 years of ocean color-derived pigment data and a regionally calibrated algorithm based on High-Performance Liquid Chromatography (HPLC) observations to resolve seven phytoplankton groups. Given the central role of diatoms and coccolithophores (haptophytes) in marine carbon sequestration, these groups are the primary focus of this study. Diatoms and haptophytes dominate variability, explaining 48% and 18%, respectively, of total chlorophyll-a. In almost the entire region, covering the mid-shelf and northern shelf-break, diatoms show a significant increase in both absolute concentration (+0.023 ± 0.01 mg m–3 decade–1, p < 0.01) and relative contribution (>3%, up to ~51%), whereas haptophytes decline in both absolute concentration (−0.003 ± 0.001 mg m–3 decade–1, p < 0.01) and relative contribution (>1%, down to ~17%). These opposing trends in the dominant phytoplankton groups are consistent with changes in light availability and wind-driven mixing and suggest a restructuring of regional carbon cycling.
Ana Delgado, Institut Mediterrani d’Estudis Avançats (IMEDEA UIB-CSIC), [email protected], https://orcid.org/0000-0002-6588-6151
Roy El-Hourany, Laboratoire d’Oceanologie et Geosciènces (LOG, CNRS-ULCO), France, [email protected]
Maximiliano Arena, Laboratoire d’Oceanologie et Geosciènces (LOG, CNRS-ULCO), France, [email protected]
Paula Pratolongo, Centro de Estudios Regionales de la Zona Semiárida (CERZOS, CONICET-UNS), Argentina, [email protected]
Guillermina Ruiz, Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Argentina, [email protected]
Gotzon Basterretxea, Institut Mediterrani d’Estudis Avançats (IMEDEA, UIB-CSIC), Spain, [email protected]
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
