First evidence of testate amoebae in Lago Fagnano (54° S), Tierra del Fuego (Argentina): Proxies to reconstruct environmental changes

Authors
Caffau, Mauro; Lenaz, Davide; Lodolo, Emanuele; Zecchin, Massimo; Comici, Cinzia; Tassone, Alejandro Alberto
Publication Year
2015
Language
English
Format
article
Status
Published version
Description
We report here the first findings of testate amoebae at high southern latitudes (54° S) from four gravity cores recovered in the Lago Fagnano (Tierra del Fuego, Argentina), where twelve taxa have been recognized. Among them, Centropyxis constricta “constricta”, Centropyxis elongata, Difflugia globulus, Difflugia oblonga “oblonga”, and Difflugia protaeiformis “amphoralis” are always present, while other taxa are randomly distributed. According to the sand/silt ratio in the different cores, the Total Organic Carbon content and the Carbon/Nitrogen ratio, as well as the presence/disappearance and abundance of testate amoebae from cluster analysis, we infer a correlation between major textural/granulometrical changes found in the cores and environmental changes. A seismic event occurred on 1949, which substantially modified the morphology of the eastern Lago Fagnano shoreline and the supply pattern from two main eastern tributaries of the lake, is recorded in the studied cores. This event has in part modified the distribution of testate amoebae taxa within the studied cores. Present results show that testate amoebae represent important indicators to detect changes occurring in the environment in which they live.
Fil: Caffau, Mauro. Istituto Nazionale di Oceanografia e di Geofisica Sperimentale; Italia
Fil: Lenaz, Davide. Universita Degli Studi Di Trieste; Italia
Fil: Lodolo, Emanuele. Istituto Nazionale di Oceanografia e di Geofisica Sperimentale; Italia
Fil: Zecchin, Massimo. Istituto Nazionale di Oceanografia e di Geofisica Sperimentale; Italia
Fil: Comici, Cinzia. Istituto Nazionale di Oceanografia e di Geofisica Sperimentale; Italia
Fil: Tassone, Alejandro Alberto. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Geología. Instituto de Geofísica "Daniel Valencio"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Subject
Tierra del Fuego
Lago Fagnano
Testate amoebae
Environmental changes
Earthquake
Geociencias multidisciplinaria
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/20072