Collecting samples with the CTD

In this video clip NIWA scientist Julie Hall describes how the CTD is used to collect samples. CTD provides baseline information for the scientists on Conductivity, Temperature and Depth and also samples phytoplankton.

Points of interest for teachers:

• Discuss how the CTD can measure conductivity

• Why is this information important?

Transcript

JULIE HALL Well this is a CTD and we’re about to launch it into a very wet and cold, windy Southern ocean tonight. We’re going to collect water samples from 200 metres to the surface for processing onboard in the laboratories

MAX QUINN (off camera) How long is it going to be down for Julie?

JULIE HALL About 20 minutes and what we’re able to do is close the bottles at different depths electronically so we can choose which depths we want to sample with the CTD.

NIKI DAVEY Okay can you bring it up to about five metres and then start dropping it down to 200 metres.

JULIE HALL These are samples that are going to be processed for looking at the DNA and biodiversity of bacteria in the Southern ocean waters and this is part of an international programme looking at different parts of the Southern ocean right round the Antarctic.