Biological weighting function for the inhibition of phytoplankton photosynthesis by ultraviolet radiation

• Main Authors: Cullen, John J., Neale, Patrick J., Lesser, Michael P.
• Format: Other/Unknown Material
• Language: unknown
• Published: 1992
• Subjects: 48; Antarctic; The Antarctic; Antarc*; Antarctica
• Online Access: http://ntrs.nasa.gov/search.jsp?R=19930042727

Severe reduction of stratospheric ozone over Antarctica has focused increasing concern on the biological effects of ultraviolet-B (UVB) radiation (280 to 320 nanometers). Measurements of photosynthesis from an experimental system, in which phytoplankton are exposed to a broad range of irradiance treatments, are fit to an analytical model to provide the spectral biological weighting function that can be used to predict the short-term effects of ozone depletion on aquatic photosynthesis. Results show that UVA (320 to 400 nanometers) significantly inhibits the photosynthesis of a marine diatom and a dinoflagellate, and that the effects of UVB are even more severe. Application of the model suggests that the Antarctic ozone hole might reduce near-surface photosynthesis by 12 to 15 percent, but less so at depth. The experimental system makes possible routine estimation of spectral weightings for natural phytoplankton.