Distribución de foraminíferos bentónicos (Protozoa: Foraminiferida) en la ensenada Quillaipe (41°32′ S; 72°44′ O), Chile: Implicaciones para el estudio del nivel del mar

Saltmarsh foraminifera are used as indicators of sea-level change which occurs during the Holocene. In Chile however, the saltmarsh foraminifera have been poorly studied, so it is unknown the feasibility of using them for this purpose. To address this issue, a research was conducted in the intertidal Quillaipe Inlet, Chile, in order to determine the vertical distribution of foraminifera and to analyze the parameters that explain their distribution and determine the species that are useful as indicators of sea level. The results revealed 18 species (nine calcareous and nine agglutinated) distributed in two zones (I and II). Zone I was restricted to the saltmarsh and inhabited exclusively by agglutinated community. Here, diversity (H′ = 0.567), pH (6.6) and salinity (18.7) values were low with a dominance of agglutinated species Haplophragmoides manilaensis. Zone II was restricted to tidal flat and inhabited by a calcareous-agglutinated community. In contrast, diversity (H′ = 0.909), pH (7.7) and salinity (32.8) values were higher, and the dominant species was the calcareous Ammonia beccarii. On the other hand, the agglutinated association Trochamminita salsa-Jadammina macrescens was restricted to the top of the saltmarsh and to low salinity and pH values. We conclude that the distribution of foraminifera is controlled by salinity, pH and the elevation of intertidal area and suggest that Trochamminita salsa-Jadammina macrescens association could be used as indicators of the maximum sea-level in the Quillaipe Inlet.