Ultraviolet radiation impact is a possible cause of marine ecosystem downturn. (Photo: EXPLORA CONICYT)

Ultraviolet radiation impact on marine life assessed

SPAIN
Friday, July 27, 2012, 16:30 (GMT + 9)

A team of Spanish and Latin American researchers has evaluated the impact of ultraviolet B (UVB) radiation on the life of organisms and marine processes.

This scientific research project has been joined by scientists from the International Global Change Laboratory (LINCGlobal), of the Higher Council for Scientific Research (CSIC) and of the Pontifical Catholic University of Chile.

Experts have worked on 1,784 experimental evaluations performed with natural radiation and organizations from different geographic areas. They have also used artificial radiation and farmed organisms in the laboratory.

The results of this study were published in the latest issue of the journal Global Ecology and Biogeography.

"The emission of fluorocarbon compounds to the atmosphere is a major cause of the reduction of the ozone layer – explains Moira Llabrés, CSIC researcher at the Mediterranean Institute for Advanced Studies. During the 70s and 80s, the ozone layer eroded and increased UVB levels, affecting living organisms in the sea."

"However, the role of UVB radiation (with a wavelength between 280 and 315 nm) as a possible cause of the global and widespread downturn of the marine ecosystems has not been quantified so far," adds the researcher.

Meanwhile, Susana Agustí, CSIC researcher at the centre, says the results of this study reveal that the increased levels of UVB radiation has generated a significant increase in mortality rates of marine organisms.

"Besides, we have found that corals, crustaceans, fish larvae and eggs are the most sensitive organisms, he adds. In addition, we will be able to determine the possible impact of the changes in UVB radiation on marine organisms."

Llabrés explains that the impacts of radiation vary from season to season and reach the highest level in spring, "which is when UVB levels are the highest."

The experiments contribute to concluding that UVB radiation can have a major impact on marine biota.

The researchers found that mortality rates fell up to 81 per cent when the UVB exposure reduced in commercial fish larvae such as cod, anchovies and other organisms, reported CSIC.

"An increase in UVB radiation by 15 per cent results in the deterioration in organisms, among marine taxonomic ranks, reaching 59 per cent," says Llabrés.

Agustí argues that "if high levels of UVB continue reaching the biosphere in the coming decades, it will be necessary to understand the impacts associated with those levels in the marine biota."

By Analia Murias
editorial@fis.com
www.fis.com

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