Collecting Agulhas retroflection data on board the RV Thomas Thompson

By Nasreen Burgher, Intern, SAEON Egagasini Node Tweet

The RV Thomas Thompson is an American military-owned vessel associated with the University of Washington as part of the University–National Oceanographic Laboratory System fleet.

The RV Thomas Thompson departed Cape Town on January 9 to collect data for 18 undergraduate students in their fourth year of study for their senior thesis.

Students collect water from the CTD for various analyses

As additional berths were available, I was one of four South African scientists aboard the vessel for the 10-day cruise. The destination was the Agulhas retroflection in the South Atlantic Ocean where we were lucky enough to collect data from an eddy, a circular current of water, as well as the Agulhas ring.

The cruise got off to a rocky start with a delayed departure due to the American students and professors whose luggage got lost on route to South Africa. As we journeyed to the South Atlantic, we deployed numerous oceanographic instruments such as the manta net, used to collect micro and macro plastics in the ocean; a Bongo net to collect zooplankton samples; a CTD to collect water at numerous depths for nutrient, oxygen, chlorophyll and isotopes analysis as well as depth, temperature and conductivity profiles of the ocean; and the uCTD, used to collect temperature and conductivity profiles.

A student assists a marine technician with the deployment of an Argo float                                                                                                                                                                                                           Students pose with Styrofoam cups intended to be attached to the CTD that will be deployed to 5 000 metres. The pressure of this depth shrinks the Styrofoam cups to a third of their size!

One of the South African scientists on board was a mammal observer and we were extremely lucky to see a pod of about eight fin whales swimming close to the ship for an hour or two – a rare and wonderful experience for everyone. Also spotted were the Atlantic yellow-nosed albatross and dusky dolphins.

I would like to thank everyone who participated in this cruise – it was an amazing cultural experience that resulted in numerous friendships.

See https://www.ocean.washington.edu for a student’s daily blog posts of the cruise.

An Atlantic yellow-nosed albatross (Thalassarche chlororhynchos) soars high above the ocean A fin whale (Balaenoptera physalus) swimming close to the ship emerges from the water