More work needed to keep Fanga’uta healthy

NUKU’ALOFA – November 30: 1.50pm (R2R Media): A lot more work is still needed to ensure that the Fanga’uta Lagoon is free from negative development. A progress report tabled at the recent Community Management Committee (CMC) on Friday, November 24 highlights the work that has been done since 2015 and the challenges still faced.

Project Manager Ta’hirih Hokafonu told the meeting that the annual monitoring for the status of the lagoon in 2016  has been completed with report now available for distribution.

Below is a snapshot of the various areas to the surrounding habitats and ecosystem services in Fanga’uta Lagoon from the Annual Report 2016 that is now available:


a) Mangroves: Mangrove plants continue to decrease within the Lagoon area, compared to previous reports.

Dredging, clearing for reclamation, land issues and high consumption of mangroves within the periphery of the lagoon is still a continuing problem.

“It is not a solution that can be solved in the short time frame of the program, however it is hope with the long term implementation of the management plan for Fanga’uta Lagoon that this will be systematic in its approach,” Ms Hokafonu said.

In the mean-time the program has directly replanted almost 20ha of mangroves thus far, and rehabilitated about 69ha of mangroves cover through the waste clean-up campaign last year in the effort to remove pollution pressure at these coastlines vegetation.


b) Forestry: Coastal and terrestrial vegetation replanting programmes varied in their effectiveness depending on the skills of the community members involved. There were also impacts due to dry periods, damaged caused by pigs and the demand for coconut seedlings for human food.

It is also noted that the two approach of replanting at town allotments and at tax allotments is only successful when coupled with regular monitoring and training provided on the ground.

The Forestry Department closely monitor the tree planting program. This has seen 85% of all plants distributed surviving with regular monitoring on the ground. As to date it has replanted 9,051 seedlings and directly/indirectly assist in improving 75.5acres of land.


c) Water Springs: For freshwater springs, there was a large increase in the water discharges recorded since last year (2015), with 50-60% more being discharged in Mu’a and Pea Sections, and a 15% at Vaini.

Part of the reason for this was because of the high rainy season prior to the survey.

Main flow of pollution comes from surface run-off, overflows from permanent polluted swamps and old quarries as well as from road drainage outlets.

It has also been noted that the area with the highest percentage of agricultural chemical use i.e. pesticides and agricultural fertilizers used by commercial farms, comes from the central District of Tongatapu, and these chemicals are  released via soil erosion and run-offs.


d) Water quality of the lagoon: The depth of the water in the lagoon is changing.

It is now becoming shallower with an  average change of 1.2 metres compared to 1.7m in 1998.

Physical aspect of water quality such as salinity, temperature and acidity/alkalinity has fluctuated in the period of 1998-2016 without any significant overall trend.

Nutrient levels in the lagoon appeared to have been dropping and levels of Nitrate, Ammonia and Phosphates appear to be below ANZECC guidelines for recreational water quality.

These results have not so far led to improvements in the symptoms of eutrophication.

Murky waters and algal growth are still dominant.

It has been suggested that for low lying areas old quarries be used as retention ponds.

On the intervention of sanitation two (2) compost toilets are being trialled at Nukunukumotu and recently in September the project approved to trial similar sanitation intervention at Vai ko Felefonu Eco-tourism site at Vaini community.


d) Birds Survey: A wide variety of birds use the lagoon as habitat, particularly for feeding at high tide and for roosting.

The greatest numbers of birds were observed in the Popua area.

A total of 12 species was recorded via vehicle and boat surveys. This includes herons, wading birds, seabirds, rails and gallinules and land birds.

Mangroves were identified as important to many species. The main threats to bird habitats were clearance for housing, reclamations, roads, pollution, eutrophication and overfishing.

In particular productivity of mudflats is dependent at least in part on water quality, so that pollution and nutrient enrichment are issues. Repeated surveys are recommended.

A key site identified as habitat for birdlife included the area of mudflats and sandflats to the east of Popua. The main issues for bird habitats in Popua included rubbish dumping, foraging by pigs and encroachment by housing developments.


e) Waste/Sanitation management: Over 350 tonnes of solid waste were collected during the clean- up campaign last year in close collaborations between Waste Authority Limited (WAL), Ministry of Health, Red Cross and Environment Department.

This covered the 26 villages around the Fanga’uta Lagoon area from Nukunukumotu to Manuka.

Some of the villages beyond the FLC area were also covered.

Most of these wastes were recyclable waste but due to limited recycling company available in Tonga, waste increase per house hold has tripled in the past years.

During the year a survey was done to view status of sanitation particularly at coastal areas of Fanga’uta Lagoon.

It was recorded that most of the leakage of feacal coliform to the lagoon is from damaged septic systems and there were many located within flood zone areas.

The Sanitation Sub-Project under the Nuku’alofa Urban Development Sector Project that’s co- funded by ADB and Department of Foreign Affairs and Trade (DFAT) with Waste Authority is assisting in trialing improved sanitation at selected sites within Fanga’uta Lagoon.


f) Soil Survey: The survey of potential source of pollution into the lagoon from agricultural sites, forest, shrub vegetation, industrial, residential sites, timber treatment site, town residential sites, town rubbish dump sites, etc. resulted with soil samples analyzed for pesticide residue and heavy metal pollution. Extremely high levels of Arsenic, Copper and Chromium were found at the timber treatment site of the Tonga Forest Product at Tokomololo.

Arsenic was the next highest mainly at the town rubbish sites and most town sites.

Cadmium was highest for the town rubbish site as well as most farming sites for squash and vegetables.

Chromium was highest for the timber treatment site and most town sites.

Copper was highest for the town rubbish dump as well as timber treatment site and most town sites.

Nickel was highest for most town sites as well as the town rubbish dump.

Lead was highest for the town rubbish site as well as most town sites.

Zinc was highest for the town rubbish site as well as most town sites.

Although various interventions are being made the limited time frame of the program does not provide the true results of the applied interventions yet, as we are still seeing repercussion of former unsustainable activities on the lagoon.

The achievements to date for the interventions is at 70%, the report added.

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