Friday, November 18, 2011

Anni's microbes

The weather calmed down during the night and work could resume. We did a CTD transect above the Coral seamounts area. CTD stands for Conductivity Temperature Depth. It goes along with a Rosette of 24 Niskin bottles, each one of those can be closed at a chosen depth.

It allows you to bring back on board bottles of seawater collected all the way from the bottom to the surface at any depths you choose.
The instrument itself gives you the salinity (conductivity) and the temperature at each depth. Nowadays other parameters have been added as, for example, oxygen.
With all this information you can distinguish different layers (water masses) and get a pretty good idea of the origin of the seawater at this depth.

Anni, a student from Oxford University, is very interested in microbes. Seawater is full of microbes quite different than the ones we have on land. Anni filtered the seawater from the Niskin bottles to see what species of microbes she will find after a DNA analysis. Did you know that we can find up to 1 million bacteria per millilitre in seawater?!