Asia Dive News : Fiji's coral reefs under threat

Beneath the aquamarine waters of the picturesque Coral Coast-mecca of Fiji tourism-corals are dying. The coral reef is becoming blighted by blossoming blotches of brown. They mark locations where algae thrives, where corals once grow along 60 kilometres of Viti Levu's south coast. Pollution from hotels and villages has become a fatal combination.

Scientists warn that without speedy counteraction the Coral Coast will become just an inappropriate name. Several scientific studies show that village piggeries , village sewage and hotels dump tonnes of nutrients or pollutants on the reef, killing corals while feeding algae growth.

All this is a terrible trend for tourism and for villages reliant on the reef for food and money-making opportunities, says University of the South Pacific scientists, Professor Bill Aalbersberg and Dr Luke Mosley.

In a report on what's happening to the Coral Coast, they warn: "A large number of tourists come to Fiji to see tropical reefs, colourful fish and to swim in clear, clean waters, not floating algae.

"If the reef ecosystems and biodiversity contained there are degraded further, the income and image of the resorts will suffer.

"Local villagers will be affected as tourism is a major source of employment in this part of Fiji, and many still rely on fish caught from the reefs for their daily consumption."

Coastal erosion along the Coral Coast will accelerate as reefs are broken down by wave action and not regenerated, they say.

Their study was completed in 2002 and their findings verified by a follow-up survey in 2004 by New Zealand's National Institute of Water & Atmospheric Research (NIWA).

This 2004 study confirms the Coral Coast is being overwhelmed by "massive growths" of brown algae caused by the flow of sewage from large hotels, agricultural and waste runoff from streams and rivers and groundwater seepage from coastal household septic systems and village piggeries.

The news is not all doom and gloom. The Coral Coast is still safe for swimming and the authorities are doing something about the pollution.

Aalbersberg, who is director of the Institute of Applied Science at USP, says nutrient concentration along the coast is an environmental problem not a health one.

On January 31, cabinet endorsed a Coral Coast rescue strategy, compiled with the support of scientists, the tourism industry and villages along Korolevu and Korotogo.

With tourism booming, the country doesn't need to become a vista of dying coral reefs and lagoons choked by seaweed.

The Coral Coast, running from the Shrangri-la Fijian Resort to the west to the Warwick Resort on the east hosts more than 100,000 tourists a year, 20% of Fiji's total visitor arrivals.

Aalbersberg says the rot must be stopped now if the Coral Coast is to be rescued.

The cost of lost coral reefs in Hawaii and cleaning up the algae cost millions of dollars annually. Jamaica in the Caribbean as a famous holiday destination is suffering the same fate.

"Coral reefs are an extremely important natural resource in the South Pacific and the rest of the world," says the Aalbersberg & Mosley study.


Algal overgrowth
"They are highly productive and are important as fishery resources, tourist attractions and for the protection of the coastline from the damaging effects of waves."

Algal overgrowth can also be attributed to overfishing as fish and other marine organisms feed and keep algae growth in check. Pollutants like nitrate and phosphate that are triggering massive algae growth along the Coral Coast are naturally present in seawater.

Too much of them becomes a problem when poor sewerage systems and untreated piggery wastes boosting nutrients to phenomenal levels.

Scientists Chris Tanner and Arthur Gold, who produced the NIWA report, estimated that Coral Coast nitrogen levels rose by more than 60% in the last 20 years.

If nitrogen control measures are not adopted at the current rates, the nitrogen level in 2014 will be more than double the 1984 level, they predict.

Nitrogen "export" from the coast to the sea in 1984 was 16,800 kilogrammes and 27,500 kilogrammes ten years later in 2004.

Aalbersberg says 35-40% of the nutrients flow from village sewers, 30-35% from village piggeries and about 15-20% from hotels. It is not that the 22 or so villages on the Coral Coast are careless letting untreated sewage into the sea.

Most of these villages have modern flush toilets promoted by local health department officials.
Flush toilets aren't the answer, however, the 2004 study says. The current septic tank model recommended for villages by the Fiji School of Medicine needs re-designing.

The New Zealand report says that flush toilets use 12 to 40 litres per flush compared to only two litres by the older pour flush waterseal toilets.

"Although both designs dispose waste water directly into a soil pit, the increased carriage water of flush toilets will markedly increase the rate of waste water flow through the soil," the report says,

"Flush toilets and soak-away pits can generate plumes of nutrient and pathogen rich effluent that move rapidly through sandy soil to coastal waters."

The newer toilets and the conventional septic tank used by villages are not designed to remove nitrogen from household wastewater, generally removing nil or at the most, only 10%.

Aalbersberg's institute has begun trials along the Coral Coast with improved toilets and septic tank designs.

One model is a composting toilet first tested at Vunisinu in Rewa and in a wetland area at Taqage.

The Taqage model removes 96% of phosphate, 83% of nitrogen, 97% of total suspended solids, 99% of faecal coliform and 96% of biological oxygen demand.


Government strategies
The improved models have been adopted for the Coral Coast rescue project endorsed by cabinet for implementation by the tourism ministry.

Government strategies also encompass village piggeries which are usually located in environmentally sensitive areas like the beach or creek. The nitrogen load from pig waste is three times higher than from human waste and about 80% reaches the sea untreated.

The NIWA report said these pollutants are a health threat besides death for coral.

"We observed children playing barefoot in the vicinity of the piggeries at Tagaqe village.

"Pigs and other livestock can be infected with numerous enteric pathogens and parasites (like Helminth worms) that are also highly infectious to human.

"Such zoonotic pathogens and parasites can be readily transmitted to humans through direct occupational exposure to faecal wastes or contaminated land, ground and surface waters.

"Exposure can also occur more indirectly through consumption of contaminated food sources, such as filter-feeding shellfish or waste-irrigated crops."

The NIWA report recommends the immediate mass relocation of piggeries away from streams and channels.

For the longer-term, the NIWA report suggests an "in pen" composting system used in New Zealand.

The Institute of Applied Science has produced a "shallow bed" composting method using sawdust or dried grass. Tested at the National Youth Training Centre at Sigatoka, shallow bed composting produces bigger and better pigs, Aalbersberg says.

"The capital and maintenance costs of this system are significantly lower than the original piggery.

"Additionally, as liquid waste from washing pens is eliminated, the waste management of the unit is dramatically simplified.

"Shallow bed composting involves the mixing of wastes with sawdust to stabilise waste material.

No new resort development can proceed without an environmental impact assessment (EIA).

The problem is that an assessment is for a single hotel. The cumulative impact of numerous hotels is not taken into account.

Aalbersberg says there is no follow-up or monitoring once an EIA is completed. Whether EIA recommendations are implemented by a developer is not known.

Tourism Minister Pita Nacuva hopes that a Coral Coasts tourism master plan will resolve this matter.

Government strategies include the establishment of a coastal commission to be a watchdog on coastal development.

While all Coral Coast hotels have waste treatment plants, scientists suggest that small hotels should have supplementary nitrogen removal systems.

The Tanner and Gold report warns: "We urge the Fijian community of regulators, engineers, scientists and hoteliers to maintain a healthy scepticism of treatment levels and operational efficiencies promised by consultants for new system designs.

"Although the reliability of small onsite wastewater technologies has greatly improved over the past decade, promised levels of nutrient removal are often overblown.

"We also recommend that "final" effluent be used for irrigation or for subsurface wetland treatment systems to provide polishing and reduce the risks associated with treatment variability."

Aalbersberg and his USP team have run a trial with a simple, relatively cheap and highly efficient waste treatment system.

This was installed at Crusoe's Retreat between Navua and Sigatoka at a cost of about $62,500. This is much cheaper than the other systems used by nearby hotels.

The Crusoe's Retreat system removes more than 90% of nutrients and treated water is discharged into the resort's flower gardens.

Another option, although a costly one will be to extend Sigatoka's sewerage system to coastal villages, hotels and any new development region.

The NIWA report praises the Sigatoka Town Council for incorporating land treatment in its wastewater treatment system. Some of its treated water is piped to a hotel five kilometres away.

If the Coral Coast is to continue to justify its name, revelations about how it is being poisoned mustn't be treated as just a research exercise, the investigators say.

"Over the last 30 years, researchers in Jamaica have documented the death of their healthy coral reefs. Urgent action is needed if reefs along the Coral Coast of Fiji do not suffer the same fate."

Source: Islands Business