Skeletonema costatum:
\nDuplicate batch cultures of coastal diatom strain Skeletonema costatum (CCMP 1332) were grown in clear rectangular 20L polycarbonate carboys under six cool white and two natural s11 type light bulbs providing\u00a0 ~200 umol photons s-1 m-2. The cultures were grown under a 12:10 light:dark cycle and mixed by hand twice per day. Sampling occurred once per day, just before the beginning of the dark period. The media was designed to assess the carbon partitioning response under stress from Si, N, and both Si & N -- however, as this experiment did not proceed as with the other three experiments here (i.e. especially in terms of initial nutrient concentration design, nutrient uptake outcomes, growing time, and parameters measured), nearly all further analyses were not initiated.
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Chaetoceros socialis:
\nDuplicate batch cultures of coastal diatom strain Chaetoceros socialis (CCMP 172) were grown in clear rectangular 20L polycarbonate carboys under six cool white and two natural s11 type light bulbs providing\u00a0 ~200 umol photons s-1 m-2. The cultures were grown under a 12:10 light:dark cycle and mixed by hand twice per day. Sampling occurred once per day, just before the beginning of the dark period. The media was designed to assess the carbon partitioning response under stress from Si, N, and both Si & N. To allow better comparison among species and treatments, all experimental flasks were started with a ~40 umol L-1 initial nitrate concentration. In those treatments limited by silicic acid (and therefore replete in N), the Si concentration was adjusted to produce the same number of replete cells as the N-stress treatments. Phosphorous was added in sufficient quantities to avoid P depletion; vitamins and trace metals were added at f/20 and f/80 concentrations, respectively.
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Thalassiosira weissflogii:
\nDuplicate batch cultures of coastal diatom strain Thalassiosira weissflogii (CCMP 1051) were grown in clear rectangular 20L polycarbonate carboys under six cool white and two natural s11 type light bulbs providing\u00a0 ~200 umol photons s-1 m-2. The cultures were grown under a 12:10 light:dark cycle and mixed by hand twice per day. Sampling occurred once per day, just before the beginning of the dark period. The media was designed to assess the carbon partitioning response under stress from Si, N, and both Si & N. To allow better comparison among species and treatments, all experimental flasks were started with a ~40 umol L-1 initial nitrate concentration. In those treatments limited by silicic acid (and therefore replete in N), the Si concentration was adjusted to produce the same number of replete cells as the N-stress treatments. Phosphorous was added in sufficient quantities to remain replete throughout the duration of each experiment; vitamins and trace metals were added at f/20 and f/80 concentrations, respectively.
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Odontella aurita:
\nDuplicate batch cultures of coastal diatom strain Odontella aurita (CCMP 595) was grown in clear rectangular 20L polycarbonate carboys under six cool white and two natural s11 type light bulbs providing\u00a0 ~200 umol photons s-1 m-2. The cultures were grown under a 12:10 light:dark cycle and mixed by hand twice per day. Sampling occurred once per day, just before the beginning of the dark period. The media was designed to assess the carbon partitioning response under stress from Si, N, and both Si & N. To allow better comparison among species and treatments, all experimental flasks were started with a ~40 umol L-1 initial nitrate concentration. In those treatments limited by silicic acid (and therefore replete in N), the Si concentration was adjusted to produce the same number of replete cells as the N-stress treatments. Phosphorous was added in sufficient quantities to remain replete throughout the duration of each experiment; vitamins and trace metals were added at f/40 concentration.
Culture studies of diatoms that dominate spring blooms in the Santa Barbara Channel were used to examine the effects of N and Si stress on the magnitude of production and the chemical composition of DOM. Species cultured were: Skeletonema costatum (CCMP 1332), Chaetoceros socialis (CCMP 172), Thalassiosira weissflogii (CCMP 1051), and Odontella aurita (CCMP 595).
BCO-DMO processing notes:
\n- Changed parameter names to conform to BCO-DMO naming conventions.
\n- Replaced -999, -999.00, dashes, and blanks with 'nd' to indicate 'no data'.
\n- Created 'replicate' column and re-arranged data accordingly from columns to rows.
\n- Assumed that: TEP =\u00a0Transparent exopolymer particles;\u00a0and ER = Extracellular release.