SCIENCE ON BOARD

The Antarctic Mission is also a…scientific mission! On board Sedna IV important research is being conducted in collaboration with institutes and organizations from different countries. A certain amount of study, analysis and compilation of scientific data is therefore part of the daily routine for Damien Lopez, chemist; Sébastien Roy and Pascale Otis, biologists; François Prévost, doctor, and Mariano Lopez, mental health caregiver. Learn about their work, below.

COMBINED EFFECTS OF ULTRAVIOLET B RADIATION, INCREASED CO2 AND CLIMATE WARMING ON THE BIOLOGICAL PUMP: A TEMPORAL AND LATITUDINAL STUDY

By Dr. Gustavo Ferreyra

For several years, obvious signs have been piling up, and the global warming hypothesis has gained increasingly wide acceptance. The temperature increase curves recorded all over the planet follow the same progression as curves indicating concentrations of one of the most significant greenhouse gases—carbon dioxide (CO2).

The CO2 released into the atmosphere comes primarily from combustion of the planet’s fossil fuels, like coal and gasoline. Water vapour, methane and other gases also contribute to the greenhouse effect. The greenhouse effect is a natural process that protects the earth’s surface from freezing or glaciation. Without the greenhouse effect, the global surface temperature would be about 33 oC colder than it is now.

The planet has its own system for keeping the biological cycles of carbon more or less balanced. Terrestrial and marine plant life capture a good part of this carbon through photosynthesis. Historically, the planet has always succeeded in keeping this balance by avoiding excessive accumulation of greenhouse gases in the atmosphere. But today, this balance has been lost. On the one hand, we now produce too much carbon, while on the other, we keep cutting down forests, the planet’s lungs. We are in the process of smothering ourselves with all the surplus of greenhouse gases building up in the atmosphere—a surplus that is now considered to be a direct cause of global warming.

Recent scientific work has shown that the planet’s oceans are excellent captors of greenhouse gases. Marine plants, mainly phytoplankton—the microscopic algae suspended in the waters of the oceans—are much more effective carbon captors than terrestrial plants. Per biomass unit, the oceanic medium is up to 100 times more productive than terrestrial media. Hence, the interest of scientists in understanding the factors that control the productivity of the oceans.

Moreover, temperature increases have an indirect effect on the oceanic ecosystem, since warming of surface waters brings about greater stratification of the water column. In other words, warm surface waters will be much less dense than colder waters deeper down. The phytoplankton, which lives in the surface waters, is therefore likely to be more exposed to the highly damaging effects of ultraviolet B radiation, which may bring about a significant decrease in biological processes linked to fixation of CO2 by the oceans (called the biological carbon pump in scientific lingo).

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This research program will gather data that will provide support to government decision-makers and inform the public at large. This project operates under the auspices of the Institut des sciences de la mer at Rimouski (ISMER-Quebec, Canada), the Université du Québec at Rimouski and the Instituto Antártico Argentino (IAA—Argentina), in collaboration with the University of Victoria (British Columbia, Canada). Financial support for this research program is provided by the Natural Sciences and Engineering Research Council of Canada (NSERC), Canada Economic Development (DEC), the Ministère du Développement économique, de l’Innovation et de l’Exportation du Québec (MDEIE) and the Dirección Nacional del Antártico (DNA—Ministerio de Relaciones Exteriores, Comercio Internacional y Culto, República Argentina).

Dr. Gustavo Ferreyra
Coordinator (IAA-ISMER)
gferreyra@dna.gov.ar; gustavo_ferreyra@uqar.qc.ca
Ecology of plankton, ultraviolet B radiation

EFFECTS OF LIGHT DEPRIVATION

By François Prévost and Mariano Lopez

In Antarctica, the austral winter is the season of the longest night. We will therefore have to deal with substantial light deprivation for about four months straight. We know that light plays a major role in the equilibrium of mammals in general and human beings in particular. Day‑night alternation synchronises the body’s internal clock to a 24‑hour period, a cyclical phenomenon called the circadian rhythm. Research on the subject has shown the importance of day and night cycles on a neuro-hormonal level; a stable circadian rhythm is therefore essential to physical and mental health.

The Sedna crew agreed to participate in a study to evaluate the psychological impact of wintering in the Antarctic. Dr Peter Suedfeld, head of research in psychology at the University of British Columbia, heads up one of the few studies conducted on the positive aspects of human adaptation to conditions of isolation, such as those that exist when wintering-over in the Antarctic.

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