Effects of ozone related UV-B enhancement on aquatic ecosystems
Effecten van door ozon depletie voroorzaakte verhoging van UV-B op aquatische ecosytemen
Veen A , Buma AGJ , Gieskes WWC , Liere L van
RIVM Report 731054002
Enhanced UV-B radiation has effects on growth, celcharacteristics and DNA cycle of phytoplankton. The increase is a result of the depletion of the ozone layer. Experimental systems were developed to measure accurately the dose of radiation to which the algal species were exposed. Also the effects were measured carefully with new developed methods. Some of the most important conclusions. The species under study revealed different quantitative reactions on higher UV-B doses. In all cases growth rate was reduced. Nutrient limited cells were not more sensitive to radiation than light-energy limited cells. The primary effect was a damage of the DNA (thymine dimer formation), which slowed down replication. Cells were becoming larger by enhanced UV-B radiation. This will influence the flow of energy through the foodchain. The mass per cell also increased at higher UV-B radiation, increasing sinking rates, so the vertical carbonflux will be disturbed.