From fish, bones and sea: Assessing coincidences between sclerochronology and isotope ecology of ichthyofauna with other paleoecological proxies for the late Holocene of the Strait of Magellan, Chile.

Torres, Jimena., Mahé, Kélig., Dufour, Jean Louis., Francisca, Santana., Harrod, Chris., Mansilla, Claudia A., Aracena, Claudia., San Roman, Manuel.

Abstract

Since the mid-Holocene, the marine hunter-gatherers that inhabited the Region of Magallanes, exploited the environment in a diversified manner, consuming marine mammals, birds and fish from different environments (San Román et al., 2016). The fishing orientation has changed over the millennia. In the late Holocene, between c. 3500 and 2500 years BP there were considerable changes in subsistence where the role of demersal fishing increases considerably as the hunting of seabirds does too (Torres et al., 2016). During the last 1000 years, the ichthyological data indicate changes in the consumption patterns, represented by a diversification especially of shore fish and abundant archaeological sites scattered between the islands and fjords (op cit.). These changes in subsistence can be linked to cultural processes, however the dramatic environmental transformations during the Middle and Late-Holocene could play a decisive role in these variations. The dramatic paleoenvironmental and climatic changes that occurred during the Mid-Holocene are well recognized on a regional and global scale, especially in relation to the change in the sea level. During the late Holocene, high fluctuations were recorded both in marine paleo-productivity as well as in terrestrial paleoecological conditions, which could affect the marine faunal assemblages. We then present the results of sclerochronology on vertebrae of Salilota australis (Moridae) to establish their population dynamics at different times during the middle and late-Holocene, and also the analysis of δ15N and δ13C on the same samples. These results are evaluated and are related to the high resolution of marine paleo-productivity and palynological records that show evident fluctuations during ca.3500 and 2500 years BP.

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Fecha de publicación: 2018