Monitoring Effects of Urbanisation on Tauranga Harbour

Since 2013, Marine Studies students and staff have been carrying out regular ecological assessment of sites around Tauranga Harbour. The goal is to monitor possible impacts of urbanisation as well as agricultural and industrial development on sub-tidal reefs.

A series of pilot studies has been carried out, survey sites have been located and data capture techniques developed. These primarily focus on measuring the physiological status of the habitat forming macro alga Ecklonia radiata against other abiotic factors.

The sites represent an ecological gradient from high to minimal anthropogenic disturbance. Growth of E. radiata has been extensively investigated previously and determined to be highly variable.

Photosynthetic rate is a sensitive physiological process that can be measured in real time and changes according to environmental conditions. Much of the research effort during 2015 focused on developing accurate and repeatable methods to quantify photosynthesis.

The potential role of heavy metals and sedimentation was also investigated. These are expected to be greatest at disturbed sites in the Tauranga coastal zone.

In early 2016, experiments to further validate the methods were carried out, with the remainder of the year undertaking manipulative studies to quantify macro algal responses to sedimentation in terms of change in photosynthetic rate.