One of our newest purchases this year was two so called in-situ pumps (“McLane pumps”). These pumps are lowered into the water, in our cases down to 250m and 500m on a cable, and kept at those depths for 1-2 hours to filter large volumes of water. In an hour, we can get 80L of water filtered. The water is not collected with these pumps, only the particles that are suspended in the water. Those remain on the filter. These particles can be algae, microbial aggregates or faeces from zooplankton (tiny water insects), or they can originate from dust particles (from land) that settled in the water. Team member Jean studies the complex chemical make-up of the settling particles in the Southern Ocean.