Stay at ICM: Antarctic Research with Catalan Accent

My name is Gastón. I am a marine biologist and I am doing my PhD in Argentina in the Institute of Diversity and Animal Ecology (IDEA/CONICET) and the University of Córdoba. My research is part of the ECLIPSE Project (http://www.eclipseproject.org) and takes place in a small Antarctic fjord (Potter Cove, King George Island) at Carlini Station. It focuses on the study of energetic interconnection between planktonic and benthic systems and the potential effects that climate change might have on these processes. In other words, how is life sustained in this coastal Antarctic system? What is/are the main food source/s for those species occurring both in the water column and settled in the sea floor? How will climate-forced changes affect the functioning of the ecosystem? These are only some of the questions that guide my work and I am trying to find the answers to those questions.

My approach to tackle this topic goes through the study of different aspects and methodologies. One study focuses on the trophic response of the Antarctic krill and a sea squirt, e.g. how the species process and assimilate different potential food sources and how this influences the production of faecal pellets (amount and speed). But I also study, how different concentrations of sediments in water affect these responses, as it is an environmental stressor linked to climate change. This has involved a large experimental series performed in Antarctica, which is fortunately finished - at least for now.

To answer (or try to) the question of what the species eat and what is providing the energy required to sustain them I am gathering evidences in different ways. First I am going to analyse samples taken by a trap deployed in the bottom of Potter Cove, which collects them monthly. This way I can sort and identify all the particles (sediment, diatoms, faecal pellets) that precipitate from the water column and reach the bottom. This will give me information about what is circling around and is available as food source. To get an idea of what is ingested and used, I am using a tool rage these days that looks at the proportion of stable isotopes. What is this about? Every organism is characterized by a 'typical signature' on the proportion of 'light' and 'heavy' forms of a given chemical element, that are known as isotopes; in marine ecology: Oxygen, Carbon and Nitrogen are commonly used. When an organism eats other, different proportions of these isotopes they are accumulated in their tissues, giving us clues about the food that species normally use.