Foraminiferal Assemblages As Bioindicators In The Western Caribbean: Albuquerque Cay (Colombia)

Abstract

The San Andrés Archipelago (Colombia) constitutes a biological hotspot for the Western Caribbean. However, expanding human populations and unrestrained exploitation of the natural resources jeopardize the sustainability of key ecosystems in most of the islands. We surveyed the benthic foraminiferal assemblages of Albuquerque Cay, a relatively isolated location in the archipelago, during an ecosystem monitoring expedition in 2018. Assemblages recorded from the lagoon and shoreface settings were characteristics of a typical Caribbean reef lagoon. Porcelaneous forms and genera that host algal symbionts, including Archaias, Amphistegina, Heterostegina, Laevipeneroplis, and Sorites, were common, as were smaller taxa, especially Quinqueloculina, Rotorbinella, and Cymbaloporetta were also found in variable proportions, while stress-tolerant and agglutinated taxa were scarce (Elphidium, Clavulina). Results suggest differences in the composition of the assemblages from both sandy cays and the reef lagoon settings, likely conditioned by hydrodynamic fluctuations and nutrient availability. Moreover, a preliminary survey of the FoRAM Index (FI) suggests moderate to good conditions for the environments of Albuquerque Cay, contrasting with estimations of the FI in other insular bodies of the area. Therefore, future studies in the archipelago could reinforce the great potential that foraminiferal assemblages have as bioindicators in this part of the Caribbean.