Dataset: Disko Bay Growth Rates

Sampling and analytical procedures: For microscopy analysis of species composition and biomass via size, 100 mL of WSW from both initial and final samples were preserved with 2% acid Lugol’s iodine (final concentration; Menden-Deuer, Lessard & Satterberg, 2001). Counts of dominant phytoplankton >5 μm in diameter were made with a 1 mL Sedgwick-Rafter slide, a minimum of 300 cells per sample were counted. Less abundant species, and herbivorous protists were counted in 50 mL Lugol’s fixed samples settled following the Utermöhl method. The entire surface of the chamber was scanned under an inverted microscope at 100–200x to ensure adequate sample size. However when low cell numbers were encountered, multiple species were binned to increase the confidence of the rate estimate. Taxonomic identification was based on morphological characteristics (Dodge, 1985; Tomas, 1997; Lee, Leedale & Bradbury, 2000; Horner, 2002).  Microscope counts were made for samples from experiments conducted between April 23rd and May 7th. No counts were made for experiments on April 20th, or May 7th and 11th. 
Species-specific growth rates for phytoplankton and herbivorous protists were calculated as the ratio of natural log transformed cell abundances over time: µ = 1/t * ln(Nt/N0), with Nt and N0 being the final and initial specie-specific abundance respectively and t the time elapsed in days.