JUNE 9
SCIENTIFIC WORKS
Sampling phytoplankton bloom
Phytoplankton are small, single-celled marine organisms that use light to create energy through photosynthesis. In the Arctic, the return of the sun not only marks the end of the long polar night, but also the start of primary production in the fjord. Spring phytoplankton bloom is characterized by a rapid increase in biomass. Controlled by light availability, nutrient concentrations, and physical characteristics of the ocean such as water mass mixing, the spring bloom is important for the marine food web and the biological carbon pump.
Every week, we collect concentrated phytoplankton samples using a hand net. We tow the net vertically from 20m deep to the surface to sample the upper water column. During a bloom, the water column typically stratifies, keeping the phytoplankton closer to the surface where there is more light and available nutrients. In the first photo below, you can see our researcher Linda Rehder holding a freshly collected sample.
This year, the bloom is dominated by a diverse group of phytoplankton called diatoms. They are characterized by having a silica shell called a frustule and can form long chains. As the bloom develops, the community of phytoplankton can also shift as different species have different biological requirements.
