Interactions between nutritional status and long-term responses to ultraviolet-B radiation stress in a marine diatom
✍ Scribed by M. J. Behrenfeld; H. Lee; L. F. Small
- Publisher
- Springer-Verlag
- Year
- 1994
- Tongue
- English
- Weight
- 836 KB
- Volume
- 118
- Category
- Article
- ISSN
- 0025-3162
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✦ Synopsis
Influences of nutritional status on the photoinhibitory effects of ultraviolet-B radiation (UVBR: 290 to 320 rim) on the specific growth rates (/~obs) and biomass of Phaeodactylum tricornutum were determined using nutrient-replete batch cultures and nutrient-limited continuous cultures. P. tricornutum cultures were exposed to UVBR doses representative of current mid-latitude and ozone-depletion intensities. Specific growth rates and biomass were inhibited from 2 to 16 % by UVBR during nutrient-replete growth. However, no effect of UVBR on #obs or biomass was detectable when nutrient limitation exceeded the potential for limitation by UVBR. Thus, a competitive interaction appears to occur between macronutrient stress and UVBR stress, such that #obs and biomass will be determined by the most limiting factor. Our results suggest that measurable decreases in phytoplankton #ob~ and biomass from UVBR are most likely in nutrient-rich areas of the ocean, while these parameters may not be appropriate for measuring UVBR stress in regions of nutrient limitation.