Macronutrients Around the Iceberg
No comments ICEBERG A43K, SOUTHERN OCEAN– Phytoplankton need dissolved nutrients, such as silicate, phosphate, and nitrate to grow in seawater. Open waters in Antarctica are rich in those nutrients, particularly in winter when plant growth is limited by short days.
At low chlorophyll concentrations of 0.15 milligrams per cubic meter (equivalent to about 11 mg carbon per cubic meter) slight decreases in nutrients are observed near the surface.
A diatom mat from ocean water surrounding an iceberg.
In the areas around our two study sites this year, Icebergs SS-1 and A43K, nitrate decreases from 36 micromol per liter at depth to 33 micromol per liter at the surface. Phosphate decreases from 2.25 micromol per liter at depth to 2.05 micromols per liter at surface.
Water melted from Iceberg A43K is enriched in nitrate, by as much as 30% (up to 47 micromol per liter). The analysis is done by Lindsey Ekern on an autoanalyzer.
Lindsay Ekern analyzing water samples for nutrient content.
The analysis method consists of mixing the nutrients with known chemicals to produce a colored reaction, proportional to the initial nutrient concentration and measured by absorption.
