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Early Season at Palmer
Posted on January 7th, 2019 No comments2018 Spring Phytoplankton Bloom!
After 30 hours of travel from the US to Punta Arenas, Chile, and then a four-day transit on R/V Laurence M. Gould across the Drake Passage, Marie Zahn and Anna Bashkirova representing the Schofield team arrived on October 6th, 2018 to Palmer Station.
Marie Zahn (left) and Anna Bashkirova (right) aboard RHIB Hadar.
Typically foul weather conditions inhibit early season sampling, but this year’s open water and manageable winds allowed us to completely capture the first spring phytoplankton bloom, peaking around November 19th.
Wind speed decreased after the first week of November and sea ice retreated, allowing sufficient sunlight and water column stratification for a bloom. Stratification was especially pronounced November 15-19 and best observable in salinity and density values from CTD profiles collected at two locations: Stations B (nearshore) and E (offshore). This was accompanied by a steady rise in fluorescence, primary production, and chlorophyll concentrations, all three reaching a peak on November 19th. Strong winds beginning November 18th soon mixed the water column, quenching the bloom.
Our measurements of primary production (mg C/m2/day) and chlorophyll concentrations (mg/m2) dropped down after the spring bloom and have remained steady since. Fluorescence profiles also reflect the spring bloom (reaching nearly 10 mg/m3 at the chlorophyll maximum) and subsequent leveling-off to ~3 mg/m3 for both Stations B and E.
Temperature (˚C), salinity (ppt), density (kg m-3), and fluorescence (mg m-3) profiles against depth in meters (L-R) for six November and December 2018 sampling events at Station B (top row) and Station E (bottom row).
Depth-integrated primary production (mg C/m2/day) values from Station B (blue) and Station E (orange) for November and December 2018.
Depth-integrated chlorophyll (mg/m2) values from Station B (blue) and Station E (orange) for November and December 2018.
Last 5 posts by Marie Zahn
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