One Saturday every month a small number of Dunedin high school students come together at the University of Otago for the Healthy Harbour Watcher programme. 

This year’s first day of monitoring was Saturday 25 March and the day was a great success for the OGHS team.

The Healthy Harbour Watch programme involves senior Chemistry students, from several Dunedin schools, travelling to monitoring sites around the Otago harbour and analysing water samples to ensure good water quality. Since 2004, Healthy Harbour Watchers have monitored 10 sites around the Otago Harbour. The group from Otago Girls’, are responsible for monitoring at three sites, Pulling point, Back Beach and Mussel Bay. At each site, in situ measurements of conductivity, salinity, temperature and oxygen content are made using a data logging probe. Water is then collected for analysis back at the labs. We also observe weather conditions and unusual features at the locations. Sea life is also monitored.

Back at the lab, collected water is filtered, ready for processing. Groups measure the amount of phosphate and nitrate dissolved in the water using by colorimetry. The main job for Otago Girls’ at the lab is filtering the water and using it to inoculate a culture medium for growing enterococci bacteria. The level of bacteria in the water is a measure of the degree of pollution from anthropogenic sources. Using water collected in a treated glass bottle, we filter the water through specially-cleaned equipment and filter paper which is later placed into a sealed agar plate and incubated for several days.

The OGHS HHW team comprises Lily Chilcott, Hayley Dick, Erin Ford, Sam Taylor, Rebecca Walker and Dr Phillips. If you are doing Year 12 or 13 Chemistry and would like to be involved there may be still be some places available, so contact Dr Phillips if interested.