Signs of volcanic eruptions in an Antarctic marine Benthic invertebrate

Abstract

The ability of some aquatic invertebrates to take up and accumulate trace elements has recently provided interesting results. The analysis of accumulated metal concentrations has numerous applications in the fields of biomonitoring programmes, but they can also be interesting for monitoring active volcanic areas and reconstructing past eruptive events. In this study, we analyzed the Antarctic limpet Nacella concinna (Strebel 1908), the most conspicuous benthic macroinvertebrate of the intertidal zone of the Antarctic Peninsula and adjacent islands. Samples were collected in Port Foster, a sea-flooded bay located in the interior of Deception Island, one of the most active volcanoes in Antarctica. The historical volcanic activity and the recent eruptions (1967, 1969, and 1970), together with the unrest episodes of 1992, 1999, and 2014¿2015, categorize Deception Island as a very active volcano. The objective of this study is to evaluate whether Mg/Ca and Sr/Ca ratios measured in the shell¿s annual bands of the limpet N. concinna are reliable proxies for environmental variations, especially for those caused by volcanic activity. The combination of images obtained with optical and electronic microscope, including cathodoluminescence, allowed us to visualize and count the growth bands of the shell, and thus to determine, together with their size, the age of the limpets. We conclude that the Mg/Ca and Sr/Ca elemental ratios are not temperature-dependent, but other variables may instead influence them, and the shells do not register the volcanic activity on Deception Island.