Production and preservation of the Arctic sea ice diatom biomarker IP25 ...

• Main Author: Brown, Thomas
• Format: Text
• Language: English
• Published: University of Plymouth 2011
• Subjects: Arctic IP25; Arctic; Amundsen Gulf; Beaufort Sea; Sea ice
• Online Access: https://dx.doi.org/10.24382/2493; https://pearl.plymouth.ac.uk/handle/10026.1/314

The presence of the sea ice biomarker IP25 in Arctic marine sediments has previously been used as a proxy measure of past sea ice conditions in the Arctic. Although the sea ice diatom origin of IP25 was established previously, the nature of its production within sea ice, along with its transport through the water column to underlying sediments and its short-term preservation therein, had not been investigated in any significant detail. Variations in the concentration of the sea ice diatom biomarker IP25, were measured in sea ice collected from the eastern Beaufort Sea and Amundsen Gulf from January to June 2008. Temporal and vertical changes in IP25 concentrations were compared against other established indicators of sea ice algal production to determine, for the first time, that approximately 90% of the total sea ice IP25 accumulation occurred coincident with the ice algal bloom period. It was further established that IP25 biosynthesis was restricted, by sea ice porosity, to within the lower few centimetres ...