OFFSHORE
TRANSECTS
Station 55 & 56
At Station 55, the ADCP was switched on for a temporal transect at 8:22 UTC. Transmission
at 2 points there were spikes in the depth, up to 30m. The estimated depth was around
65 m. Relating back to the temperature graphs and the location of the thermocline
at station 55, it can be interpreted that the pulses returning to the receiver were
more intense in their number, possibly because of the biology at the thermocline.
At the thermocline is usually where phytoplankton and grazing zooplankton congregate
because of their nutrient requirements. However, on looking at the data for photosynthetic
Active Radiation (PAR), fluorescence and turbidity, it is unlikely that it is plankton
seen at this depth. 30 m has too little light for a significant amount of plankton
to be at that site. There is also little evidence of heightened fluorescence in this
area, which is a proxy for chlorophyll producing phytoplankton. The spikes could
still be other nekton, however they may also be an artefact of the ADCP. This was
a similar picture for Station 56, which had no significant evidence of phytoplankton.
The Station 56 profile began at 10:08 UTC, with the same estimated depth of 65 m.
Station 57 & 58
At Station 57 and Station 58, the influence of the tide starts to become more evident.
On the other hand, the ADCP frequency is potentially too low for all stations to
interpret picking up an intense signal change for something as small as biological
activity. At Station 57, the maximum depth was 43.25 m, and the sample began measurements
at 11:31 UTC. The current at this location was about 0.085ms-
The views and opinions expressed on this website are those of individuals within group 8 and are not associated with The National Oceanography Centre, University of Southampton or Falmouth Marine School.