Interactive effects of ozone depletion and vertical mixing on photosynthesis of Antarctic phytoplankton
Article Abstract:
Research into the inhibition of photosynthesis of Antarctic phytoplankton by ambient ultraviolet (UV) radiation during incubations has used a model of UV-influenced photosynthesis in the presence of vertical mixing. This approach has made it possible to describe the key relationships between vertical mixing, solar radiation and physiological responses of Weddell-Scotia Confluence phytoplankton to UV radiation. It was concluded that ozone depletion can hamper primary productivity in open waters of the Antarctic. However, natural variability in exposures of phytoplankton to UV radiation plays a significant role in mediating the impact of water-column photosynthesis.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
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Influence of iron availability on nutrient consumption ratio of diatoms in oceanic waters
Article Abstract:
Iron limitation can have an impact on the ratio of consumed silicate to nitrate and phosphate in oceanic waters, according to the results of seawater and culture experiments undertaken in three updwelling areas of the Southern Ocean, the subarctic North Pacific and the equatorial Pacific. Iron deficiency seems to affect the diatom C:Si ratio in a similar way to the Si:N and Si:P ratios, as iron-limited diatoms have little variability in C:N:P elemental composition. These findings are consistent with palaeoceanographic records that back up the iron hypothesis for the lower concentration of CO2 in the glacial atmosphere.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1998
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Iron grip on export production
Article Abstract:
The rate of carbon sinking below the surface water in oceans increases as the iron content of the water increases. Marine phytoplankton take up carbon from the environment and a portion of the carbon sinks, which is known as export production by the plant. The high nutrient, low chlorophyll ocean areas have a low amount of iron which creates an imbalance in the iron-nitrate ratio. The imbalance causes suboptimal photosynthesis activity. Iron in the western Pacific is entrained in an undercurrent below the Equator.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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