Our sampling was done at the L4 buoy in the English Channel. In situ measurements
are made at this location weekly by Plymouth Marine Lab. We took water samples from
NISKIN bottles in multiple locations at L4 and analysed our samples to measure the
oxygen, chlorophyll and nutrient concentrations.
Oxygen measurements
- 1ml of sulphuric acid was added to dissolve the precipitate with a magnetic stirrer
bar to mix the solution leaving a yellow liquid with no precipitate.
- The solution is then titrated to find an end point using sodium thiosulphate. Using
the end point the amount of oxygen can be calculated.
Chlorophyll measurements
- Analysed the samples using a fluorometer.
- 7mL of acetone was put in the fluorimeter giving a fluorescence reading in umol/L.
- This is then multiplied by 7/50 to give the fluorescence of 50mL.
Nutrient samples
- Our nutrient samples were analysed in an autoanalyzer that can process 1 sample
per minute, measuring nitrate, phosphate and silicate.
