Late Holocene environmental change in Celestun Lagoon, Yucatan, Mexico

Abstract Epikarst estuary response to hydroclimate change remains poorly understood, despite the well-studied link between climate and karst groundwater aquifers. The influence of sea-level rise coastal geomorphic on these estuaries obscures signals, thus requiring careful development paleoenvironmental histories interpret paleoclimate archives. We used foraminifera assemblages, carbon stable isotope ratios (δ 13 C) carbon:nitrogen (C:N) mass organic matter in sediment cores infer environmental changes over past 5300 years Celestun Lagoon, Yucatan, Mexico. Specimens (> 125 µm) from modern core top sediments revealed three assemblages: (1) a brackish mangrove assemblage agglutinated Miliammina Ammotium taxa hyaline Haynesina (2) an inner-shelf marine Bolivina , Hanzawaia Rosalina, (3) dominated by Ammonia Elphidium . Assemblages changed along lagoon channel salinity vegetation, i.e. seagrass mangrove. In addition deposited since cal yr BP are comprised two more defined Archaias Laevipeneroplis, which indicate Thalassia seagrasses, Trichohyalus, indicates restricted inland ponds. Our data suggest that Lagoon displayed four phases development: pond (5300 BP) shallow unprotected coastline with barrier island initiation (4900 protected (3000 BP), (4) surrounded mangroves (1700 BP). Stratigraphic (temporal) assemblages resemble spatial differences communities across lagoon, southern sector northern region. Similar temporal patterns have been reported other Yucatan Peninsula lagoons cenotes (Nichupte, Aktun Ha), suggesting regional sea level change, including controls (longshore drift) salinity, as observed today. Holocene progressively northwest coastline, reducing mixing seawater rain-fed submarine discharge. Superimposed this signal, reflect most severe wet dry episodes, coincide records lowland lake archives (Chichancanab, Salpeten). results emphasize need consider evolution when using epikarst for reconstruction provide evidence Peninsula.