The effect of iron and light co-limitation on the oceanic diatom : Pseudo-nitzshia granii ...

• Main Author: El-Sabaawi, Rana
• Format: Text
• Language: English
• Published: University of British Columbia 2009
• Subjects: Subarctic
• Online Access: https://dx.doi.org/10.14288/1.0090162; https://doi.library.ubc.ca/10.14288/1.0090162

Light and iron (Fe) Co-limitation occur in temperate, Fe-limited regions in seasons where days are short and the mixed layer is deeper than the euophotic zone. In the first part of this study, the effect of light and Fe co-limitation on Pseudo-nitzschia granii isolated from the NE Subarctic Pacific was investigated. This was one of the first studies to investigate the effect of Fe and light on the physiology of oceanic, pennate diatoms in artificial seawater. Fe-limited P. granii grew at slower rates than Fe-replete cells, and the former showed signs of chlorosis and silica deficiency. P. granii was efficient at utilizing light, especially low light. Light and Fe were found to affect different aspects of photosynthesis. Whereas Fe affected the quantum yield of photosynthesis, light affected photochemical efficiency. Despite low growth rates, P. granii was able to survive and grow under Fe-limitation. This was possibly because Fe limitation increased the activity of non-photochemical quenching mechanisms, ...