Birkenhead College—11 March 2015

Birkenhead College is a secondary school located on Auckland’s North Shore.  It is a recognised centre of academic excellence and cultural focus and sports achievement.

This year, Year 11 students are studying the geography of the Kaipara coast and Araparera Valley and they had a field trip to CUE Haven and a neighbouring dairy farm to learn more about the geography of the area and about the impact of farming, development and our restoration project on the Araparera River and Kaipara Harbour.

The plan for the day was that the group would first do a walking tour of the property to see the restoration activities and also to observe the area geography.  After the walk, Rachel Griffiths of Auckand Council’s WaiCare group and Dylan Clarke of Auckland Council’s Land Care group would do a presentation on water quality testing and observations of aquatic macroinvertebrates to help the students gain a perspective on how geography, vegetation and farming practices impact water quality.

Thirty-four students arrived with geography teachers Tamsin White and Carter Murphy at about ten and we started out with a welcome and a talk about the history of the CUE Haven project.  We explained that the property had once been a dairy and beef farm and talked about the impact of those activities on the land and streams and ponds.  We explained the history of our project and what we were trying to accomplish and the progress we have made – thanks to the efforts of all our wonderful volunteers.

We then started the walk and along the way Tom pointed out features of the property.  He showed the students how each different year’s planting looked and showed them the difference between the wetlands and other areas of the property.

It was a long hot hike up to the top of the property but once they got there the students had a chance to view the geography of the Araparera Valley and some of the Kaipara Harbour catchment to get a better idea of how streams feed the harbour and the different kinds of land the streams flow through.

We then walked back, taking a different route so that the students could explore the wetlands via the wetlands boardwalk.  They then took a well-deserved break and had their lunch.

They also made friends with a friendly native copper skink.

Earlier, Rachel and Dylan had gone out to the field and gathered water and specimen samples from the gully steam to use for the waicare presentation.

Rachel started off her presentation with an introduction to the Waicare programme and the issues with water quality and protection of waterways and wetlands.  She explained that there are three areas of water testing—physical, chemical and biological.

The primary physical characteristics are temperature and clarity.  She used a thermometer to check the temperature.  This is important because most aquatic creatures cannot tolerate high temperatures.

Rachel had one of the students help her as she demonstrated the use of a clarity tube to check the clarity of the water.  This is a test to help determine how much sediment there is in the water.  Low clarity can have an adverse impact on creatures living in the water.

The next step was to do the chemical tests.  These included tests of pH (a test of the hydrogen ion concentration in a solution which indicates acidity or alkalinity).

And tests for dissolved oxygen.

Rachel also did tests for nitrates, nitrites and phosphates.  Each of these tests help to determine the quality of the water and how well it can sustain life.  Chemical or organic runoff can affect the pH and the presence of nitrates and phosphates can indicate fertilizer or other chemical runoff affecting the waterway.  Some of these chemicals can contribute to algal blooms which can be dangerous to both water and land animals.

The last test was biological and that involved studying water samples and identifying the creatures living in the sample.  The types and variety of creatures are an indication of the water quality because while some species tolerate a wide range of conditions some are very sensitive to the environment and will only be found in healthy waterways.

Rachel set out several sample trays and gave the students a chance to see how many creatures they could find using field identification charts and also check out the water clarity using the clarity tubes.

Rachel was really pleased that the students found and identified a free living caddisfly and a flat mayfly, both of which only live in relatively clean and healthy streams.

A great end to a successful field trip!

We want to thank Auckland Council for making Rachel and Dylan available and a big thank you to them for all their hard work.  Your presentation was very interesting and educational and we really appreciate your time and effort.

The students then headed back to their bus for their next stop—a neighbouring dairy farm where they would learn about farming practices that minimise the effect of dairy farming on the land and water.

Before they left the teachers and students gave us a completely unexpected and amazingly generous gift that will be used towards the purchase of plants!  Thank you so very much. We hope you will come back and help us plant them!!

We want to thank teacher, Tamsin White for organising the visit.  We really enjoyed meeting and working with the Birkenhead College teachers and students. We wish you all success in your future endeavours and hope you will come back again soon.