This week was boat week for our Oceanography course! We were getting accustomed to the sampling and measuring methods used by marine biologists and physical oceanographers. We were on three (!) different boats and got some lab experience as well.
Rib and Lab
On our Rib day, we conducted salinity measurements and took samples from the Itchen River (Southampton). We made a transect from downstream the Itchen to upstream, during an incoming tide. By doing so we saw a decrease in salinity from 34.4 to 0.2 psu, and could recognize where the biggest shift takes place. That was very far upstream! The tide comes in all that way.
In the lab, the samples were processed and would be analysed on a later day to check for phosphate and silicon content. In the coming weeks, we will be working on a report discussing the relationship between the incoming tide (thus salinity profile) and both of the chemical elements.
The Lab day was quiet but good. We worked with a big group of 10 people. My friend Aniela and I were responsible for the reference data. We set up a dataset of known Phosphate and Silicon mixtures to interpolate from and to determine concentrations in the samples taken the day before.
The Conway took us on a trip across Southampton waters to do a Side Scan Sonar track. The tow “fish” behind the boat shows a sonar picture of the sea floor and bottom structure. This felt like a very cozy night (although it was during the afternoon, it was getting dark already), just talking about sonar and looking at the sunset.
Callista day was a full day of working in shifts to get all our data for the boat week report. We had three shifts: one behind the computers managing the equipment; one group to do the analysis in the onboard wet lab!; and one group to gather all the incoming data in the spreadsheet. I feel like we got the best shifts because we could sit down during lunch (data gathering) and see the sunset during deployment of equipment on board. Having the option to work on your data on board gave it a whole new dimension as well. The group work was pro.
We took zooplankton samples with the tow net. Checked light penetration with the Secchi disk. Prepared more phosphate and silicon samples from the CTD. The CTD also got conductivity (salinity), temperature and depth measurements on real-time. The samples were also used for chlorophyll infrared tests – giving insight into the phytoplankton activity. Last but not least we did two transects with flow speed across the channel (ADCP). We were busy with a lot!
The last day of the week covered analysis of our zooplankton tow net samples. We were to quantify the number and diversity of zooplankton species in the 2 samples (morning and afternoon) to see if there was any difference between the two. Unfortunately there were only two species abundant: the Copepod and the Oikipleura. I would’ve loved to see some more zooplankton, but I will see those in my zooplankton course practicum in two weeks I suppose.
Thank you for reading about my boat week! It was a long read. And a long but satisfying week. Bye ❤