CI group studies ecosystems on Tonga field trips

Monday August 28, 2017 Written by Published in Environment
Some of the Cook Islanders who recently began the R2R study programme: (from left) Paul Maoate (ICI), Muraa’i Herman (NES), Liam Kokaua (TIS), Keu Mataroa (ICI). 17082704 Some of the Cook Islanders who recently began the R2R study programme: (from left) Paul Maoate (ICI), Muraa’i Herman (NES), Liam Kokaua (TIS), Keu Mataroa (ICI). 17082704

This weekly column is contributed by Te Ipukarea Society. It deals with conservation and environmental issues of interest to the Cook Islands.


Liam Kokaua from Te Ipukarea Society recently began a postgraduate certificate in Ridge to Reef Sustainability through Queensland’s James Cook University (JCU), alongside fellow Kukis from the Cook Islands National Environment Service and Infrastructure Department.

The group were in the Kingdom of Tonga in August for a post-graduate training week, hosted by Secretariat for the Pacific Community (SPC) and run by lecturers from JCU. The postgraduate certificate is a part-time course, and students will complete one paper each semester with the aim of completing all four papers by the end of the first semester in 2019.

The study programme was created to build the capacity of Pacific Island people from the 14 Pacific Island countries who are a part of the GEF Pacific Ridge to Reef (R2R) programme. The group of student’s first study paper focuses on “Ridge to Reef Ecosystem Dynamics”.

In Tonga, days usually consisted of morning and afternoon classes, with a field trip around midday. During the class sessions, the new students covered the requirements of the assignments they will be working on this semester. Each of the four field trips took the group to a different type of ecosystem, as what better way to explain ecosystem dynamics than to visit the sites themselves?

Day One: Reef Flat Habitat

The team visited this site at low tide to better observe the different biodiversity present. It was interesting to note that the animal species and abundance changed as they travelled further from the beach towards the reef. This site was abundant in silty-sandy flats, patches of seagrass, and dense coral groves.

Day Two: Rocky Shore

This site was also protected by a reef and quite calm near the shore. Within the back-reef area, holes in the coral rock (rock pools) turned out to be hotspots for marine biodiversity. There was high wave energy action around the channels and where the reef meets the ocean, which has led to formation of blowholes and other rock sculptures. Biodiversity (particularly coral and seaweed species) was also different in these high energy areas.

Day Three: Mangrove system

Consisted of two sites, one relatively pristine mangrove site at Captain Cook’s landing and another mangrove site which has been partially cleared and replaced by groins in an attempt to create sandy beaches along a coastal road. The important role of mangrove systems as a coastal protection, sediment filter, and animal habitat was also discussed.

Day Four: Port and Urban Development

The team visited the national port and a former mangrove tidal flat which has been cleared and/or cut off from its connection to the sea. Large areas of this coastal area have been filled in with rocks in order to provide solid ground for housing development. A large man-made river has been created to allow water to drain out to sea, while there are also plans to turn the area into a tourist hub including a golf course. The environmental impacts of this infilling and the associated development are uncertain.

Day Five: A special case study

The group visited a large mangrove area which lay in between a village and an area which had agricultural potential. A road was built across the mangrove area to connect the village to the land and provide access to the planting lands. However, due to poor design and a lack of understanding of the ecosystem, the road blocked off the flow of salt water to the other side.

As a result the mangroves in this area were experiencing severe dieback, particularly one species of mangrove (there were three species in the area, inhabiting different tidal zones).

The group learned that different species of mangroves can tolerate different levels of salinity, which is the reason that one mangrove species died off completely due to the road being built while others did not. The whole habitat could have been protected with a better study of natural processes occurring in the area and engineering to allow water to flow underneath the road.

Meitaki ma’ata to Global Environment Facility (GEF) for funding the Pacific Ridge to Reef Programme, SPC for hosting the event, and NES for the support.


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