(Table 1) Biological and chemical characteristics of surface water stations during Nathaniel B. Palmer cruise NBP06-08 to the Ross Sea ...

• Main Authors: Tortell, Philippe Daniel, Trimborn, Scarlett, Li, Y, Rost, Björn, Payne, Christopher D
• Format: Dataset
• Language: English
• Published: PANGAEA 2010
• Subjects: Event label; Latitude of event; Longitude of event; Depth, top/min; Depth, bottom/max; DEPTH, water; Chlorophyll a; Nitrate; Dominant species of live fauna; Carbon dioxide, partial pressure; Silicon dioxide; Surface water sample; NBP0608; Nathaniel B. Palmer; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas SPP1158; Antarc*; Antarctic; Phytoplankton; Ross Sea; Sea ice
• Online Access: https://dx.doi.org/10.1594/pangaea.858519; https://doi.pangaea.de/10.1594/PANGAEA.858519

We present results from a field study of inorganic carbon (C) acquisition by Ross Sea phytoplankton during Phaeocystis-dominated early season blooms. Isotope disequilibrium experiments revealed that HCO3- was the primary inorganic C source for photosynthesis in all phytoplankton assemblages. From these experiments, we also derived relative enhancement factors for HCO3-/CO2 interconversion as a measure of extracellular carbonic anhydrase activity (eCA). The enhancement factors ranged from 1.0 (no apparent eCA activity) to 6.4, with an overall mean of 2.9. Additional eCA measurements, made using membrane inlet mass spectrometry (MIMS), yielded activities ranging from 2.4 to 6.9 U/[mg chl a] (mean 4.1). Measurements of short-term C-fixation parameters revealed saturation kinetics with respect to external inorganic carbon, with a mean half-saturation constant for inorganic carbon uptake (K1/2) of ~380 mM. Comparison of our early springtime results with published data from late-season Ross Sea assemblages showed ... : Supplement to: Tortell, Philippe Daniel; Trimborn, Scarlett; Li, Y; Rost, Björn; Payne, Christopher D (2010): Inorganic carbon utilization by Ross Sea phytoplankton across natural and experimental CO2 gradients. Journal of Phycology, 46(3), 433-443 ...