Experiments have already begun to study the effect of solar radiation and temperature on macroalgae.
Nine campaigns and new experiences in the Antarctic summer
For the UVigo team this is the ninth research campaign they are developing in Antarctica, where they have already carried out projects in the years 2004, 2005, 2009, 2010, 2011, 2016, 2017 and 2023, in addition to another research in the Strait of Magellan. However, each new campaign remains unique, Lastra acknowledges, because although "the first time you arrive in the Antarctic is special, of course, the others are too, always, although in different ways".
All this accumulated trajectory in Antarctic research also implies a better preparation to face the extreme conditions in which they have to work, even though the campaigns take place during the Antarctic summer. "Once you have some experience", admits Lastra, "you know what you are facing and there is not as much uncertainty or sense of adventure as the first time, and this allows you to focus your attention on other aspects, such as visions and reflections than the first once you couldn't experience it because your senses were saturated with the spectacular Antarctic environment".
Regarding working in an extreme environment like this, with temperatures that in recent days ranged between 0 and 4 degrees, Lastra considers that there are no special challenges. "The security protocols are very strict and the military at the base are always waiting for us and that we don't lack support to carry out our work." The only aspect that can be "a bit compromised", he points out, is the navigation in zodiacs between the different sampling points, "which is sometimes a bit delicate when we get caught in bad weather".
Assess the effect of solar radiation and temperature on macroalgae
The Radiant project is one of the 30 that were selected to be part of the XXXVII Antarctic Campaign coordinated by the Land Army that started on January 1 with the arrival of the first teams at the Gabriel de Castilla base. Vigo's research focuses on deposits of macroalgae from the rocky substratum deposited on the coastline by currents and tides, which function as generators of numerous ecological processes associated with their decomposition, including consumption, habitat supply and biogeochemical activity of the sediment. The objective is to quantify these processes in ten beaches along the coast of Porto Foster and to evaluate their effect on the release of nutrients and the emission of CO2 through the sediment, as an estimator of the metabolic activity of the substrate.
In this new stay, they will replicate the sampling carried out last year, in the first campaign of the project, along the arc of the bay and will also carry out two other experiments, one of manipulation of the natural environment and the other in mesocomic conditions in the laboratory. In the first of them, selective UVA/B radiation filters will be used to assess the hypothesis that the increase in incident UV radiation due to the opening of the ozone hole will cause alterations in the decomposition processes of the macroalgal biomass accumulated in the sedimentary intertidals of Porto Foster. The experiment in mesocosms, on the other hand, will make it possible to study the effects of the alteration of the UVR on the primary consumers. For this, the consumption rate of the herbivorous amphipod Gondogeneia antarctica (Chevreux, 1906) will be analyzed on fragments of two species of Antarctic macroalgae, Palmaria decipiens and Desmarestia antarctica , which will previously be irradiated with excess UVA and UVB.
First days of work
After a few days to organize and prepare the material, this Monday the CIM team began the process of searching for macroalgae along Fumarolas beach. Given the time of year, they initially found few specimens in good condition that could be used in the planned experiments, so the sampling is maintained during these first days. At the same time, they also carried out tests on the lighting of the UV-A and UV-B lamps that will be used in the planned herbivory experiments and on Tuesday they also collaborated in the installation of a seismic base at the beacon located in Fumarolas south together with several members of the staff of the Gabriel Base Castile. In the last few hours, they installed the necessary systems to carry out the experiments on the Fumarolas beach
Results of the 2023 campaign
After analyzing for several months the samples and data obtained in the 2023 Antarctic campaign, CIM researchers were able to determine that algae subjected to excess UV reduce their rate of bacterial decomposition and mineralization, with an antagonistic effect of temperature, which causes a substantial increase in the metabolic rate of the substrate in the face of temperature increases in the range predicted by the IPCC for the north-west of the Iberian Peninsula, of between 0.5 and 1 C in the next decade. In addition, in collaboration with the members of the Erupting project, Antonio Polo and Antonio Caracausi, samples were taken of the gas emitted on the different beaches with the aim of analyzing the isotopic signature of CO2 to determine in what proportion the measured emissions are of volcanic or biological origin, something large interest in a volcanic environment such as that of Deception Island.