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Method
100ml water samples were taken from each fired niskin bottle on the rosette and transferred to a brown glass bottle containing LUGOLS and labelled with a yellow number.
These samples were then analysed in the lab. A 10ml aliquot was transferred to a small bottle and labelled with the boat reference. Using a pipette, 1ml of the sample was transferred to a Sedgewick Rafter counting chamber. The phytoplankton species present in 100 (20x5) squares of the 1000 square grid were identified and counted using a light microscope at magnification x10. This abundance was scaled up to number of phytoplankton per litre by multiplying by 10000.
Results
Figure 1 displays the abundance of different phytoplankton genera collected in the
samples from different depths and times at Station E1. Throughout the day, the total
phytoplankton abundance increases. The total number of phytoplankton was lowest at
Station 29, equal to 20000 L-
Analysis
The observed total phytoplankton abundance and number of genera increases with time
are likely due to increasing light intensity as the day proceeds. This would act
as a que for different phytoplankton species to carry out diel vertical migration.
This is supported by an observed shallowing of the deep chlorophyll maximum. Most
of the phytoplankton resides at depths between 14-
Phytoplankton
A time series of the phytoplankton diversity and abundance at the E1 station throughout the water column