Biogeochemistry of selenium in the oceans of the southern hemisphere ...

• Main Author: Wake, BD
• Format: Thesis
• Language: unknown
• Published: University Of Tasmania 2023
• Subjects: Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.25959/23241380.v1; https://figshare.utas.edu.au/articles/thesis/Biogeochemistry_of_selenium_in_the_oceans_of_the_southern_hemisphere/23241380/1

Selenium (Se) is a key micronutrient for marine primary productivity in the remote ocean. The element is known to be essential for phytoplankton species growth, but there is limited information on its role and physiological function. This study is the first to investigate basin-scale distributions, speciation and biological requirements of Se for phytoplankton in the various water masses of the Southern Hemisphere, ranging from the subtropical to the polar oceans. The thesis describes the development of a new shipboard method based on hydride generation with cryogenic trapping and atomic fluorescence detection for the determination of Se species in seawater. A detection limit of \\(5 pmol\\) `l^-1` `Se` in a 10-ml sample was achieved, with precision better than 3.5% for Se(IV) standards (\\(0.3-12.7 nmol\\) `l^-1`). Accuracy was determined by recovery studies on natural samples and certified reference seawater. An ocean transect from Australia to Antarctica along the meridional CLIV AR I9S line ...