Phytoplankton responses to natural UV irradiance during early spring in the Weddell-Scotia confluence: an experimental approach

FERREYRA, G.A, SCHLOSS, I.R, NEALE, P.J, DEMERS, S.

Antarctic Journal of the United States

National Science Foundation

Año: 1994 p. 268 - 270

In the last few years, antarctic stratospheric ozone thinning has resulted in an increase of ultraviolet (UV)-B radiation incident on the southern ocean surface waters. Recent investigations have suggested that the enhanced UV-B can decrease areal primary production in the southern oceans, but the exact reduction remains controversial (6-12 percent, 0.12-0.33 percent). One factor that can reduce long-term exposure to UV radiation is vertical mixing of the water column. Furthermore, several internal mechanisms have been suggested as possible strategies to minimize cell damage. The synthesis of photoprotective substances could reduce deleterious effects on microalgae physiology. Most of the experimental research deployed until now has focused on short-term exposure effects and has not considered the influence of irradiance under mixing conditions of the water column. During the austral spring 1993 the long-term (days) effects of natural UV radiation on phytoplankton physiology was studied using fixed and variable UV filters. Primary productivity and synthesis of photoprotective substances were measured.