Project Baseline Lake Pupuke: Monitoring the Lake and Building Collaborations

My name is Ebrahim Hussain and I am a South African living in New Zealand and I am a passionate GUE diver. I work for the Auckland Council Environmental Monitoring & Evaluation team were one of my responsibilities is running the Regional Lakes Water Quality Monitoring Programme. I am now also the founder of the Lake Pupuke Project Baseline initiative. 

Lake Pupuke is a large volcanic crater lake and is quite deep (57m) it also has a fully urban catchment which makes it a unique ecosystem in New Zealand. This lake is a high value recreational water body and an Auckland icon. It is regularly used for a variety of water sports and was used as a venue for the World Masters Games 2017.  

This project came about after I had been diving in Lake Pupuke for a few years and had noticed a decline in subsurface water clarity. Several local residents and dive schools that I spoke to had noticed the same thing. In 2014 a thick algal bloom had developed across the entire lake during the summer. This was thought to be an isolated incident, but the bloom reappeared in the following summer. This cycle has been observed every year since 2014 and the subsurface water clarity is still declining. The extent of the bloom or why the water clarity is dropping is not well understood.

Out of curiosity I continued to regularly dive in the lake in an attempt to better understand the full extent of the environmental changes. In so doing I discovered that there has been an increase in organic silting and the algal bloom appears to stratify between distinct thermal layers (this phenomenon has not been documented previously in this lake), I had noted the depth and time at which I found this subsurface algal layer. I wanted to make better use of my ad hoc notes and hopefully get a more robust monitoring programme together. I approached various local authorities with a project proposal, but due to their limited resources and my inconclusive proof the project was not funded.

This is when I found the GUE Project Baseline initiative. The use of skilled volunteers would allow me to service this resource heavy monitoring programme at a greatly reduced cost. I submitted my proposal to the GUE Project Baseline office and it was accepted. I then looked for sponsorship to cover some of the costs involved in building the monitoring station. The Auckland Council generously payed for all the materials needed to build the monitoring rig and the passionate GUE community in New Zealand all agreed to help out with the installation.

Myself and Mike McMurtry designed and built the monitoring rig and with the assistance of the dive team (Belen Andres, Philippe Guerra, Andrew Simpson & Russell Hughes) we set out to install our first monitoring station.

The project aims to collect a variety of surface and subsurface data which will feed into and complement the current monitoring programme run by Auckland Council. In this way we will have a completely holistic approach to tracking environmental change and anthropogenic stressors in the lake. This collaborative project makes Lake Pupuke the most intensively monitored lake in Auckland. 

I have recruited a local school to assist us in collecting the surface data which includes basic meteorological data, land use changes, surface water clarity and bird counts. The subsurface data will include horizontal visibility in the littoral zone, continuous temperature, dissolved oxygen and fish counts. We intend to monitor sedimentation and submerged macrophyte abundance in the near future as well as installing additional stations to get better spatial coverage.

The ultimate goal is to gather baseline data sets and develop possible trends which can be used to identify key environmental and anthropogenic issues. This data will be used to assist in the development of more effective management strategies and will lead to a healthier lake.

Submitted by Ebi Hussain-Project Manager for Lake Pupuke

Project Baseline has been at the forefront of increasing awareness of Florida reef decline as well as monitoring the health index for nearly 70 marine and freshwater environments world-wide since 2009. Watch as Project Baseline takes CNN underwater for special media coverage on Florida reefs -