The impact of UV-B radiation and different PAR intensities on growth, uptake of C-14, excretion of DOC, cell volume, and pigmentation in the marine prymnesiophyte, Emiliania huxleyi

The impact of UV-B radiation (280-320 nm) and different PAR (400-700 nm) in tensities on growth, uptake of C-14, excretion of DOG, cell volume, and pig mentation in the marine prymnesiophyte, Emiliania huxleyi, was studied in a laboratory experiment. In UV-B-exposed algal cultures at UV-B doses > 2.7 kJ m(-2) UV-B-BE, changes in incorporation and excretion rate of C-14, and indications of DNA damage (in the form of termination of cell division and enlarged cell volume) were observed. Since the UV-B doses used are represen tative of UV-B doses in the top layer of clear ocean water and E. huxleyi i s a common bloom-forming algae with a wide geographic distribution, it is s uggested that current UV-B intensities have an impact on primary production and phytoplankton biomass. (C) 2000 Elsevier Science B.V. All rights reser ved.