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Wakatobi Research

To protect the coral reefs that Wakatobi goes to great length to protect, the resort installed a coral reef health early warning system in fall 2009. Call the Rainbow Sensor Program, arrays of sensors have been installed at two popular dive sites ‘Zoo’ and ‘Roma’.

The first data sent from the scientists in Los Angeles show the water at ‘Roma’ to be unusually free of organic components that are often the result of human sewage.

What this says is that Wakatobi’s policies of working with the local residents to protect their coral reefs from over fishing and human contaminants are working. Wakatobi’s reefs remain pristine, an unusual result for reefs that are visited by modern dive resorts.

Both the Wakatobi Resort management AND the local population should be proud of this accomplishment.
--Tom Reynolds,
Rainbow Sensor Program Manager (www.rainbowsensor.com)


The Rainbow Sensor

The Rainbow Sensor works by comparing how the reef’s water attenuates the light.
As the diver knows, water removes the sunlight unevenly, removing first the red, then orange, yellow, blue, green and so on. What most divers don’t know is that attenuation in the blue wavelength is increased by the presence of organic material.

In normal, clear seawater the green attenuation is greater than the blue attenuation. However, with the coral reefs near locations with significant human population, human waste adds organic components to the seawater. The result is that the blue attenuation is actually greater than the green attenuation, sometimes by a significant amount. When that occurs, alarm bells should sound. The reef is at risk for an algal bloom that will stifle coral growth and degrade coral health.

At ‘Roma’ however, the blue attenuation is clearly less than the green attenuation, indicating water quality unpolluted by human waste. The site routinely exhibits diver visibility in excess of 30 meters using the Rainbow Sensor Program visibility measurement process. This is a significant and difficult accomplishment for reef management.

rainbowsensor2 wakatobi DiveResort Waterquality


The top graph shows the light attenuation in the white (all wavelengths), green and blue region. A larger K means more attenuation. The K in the blue region is inversely proportional to the optical depth, a scientific term that relates very closely with what divers call visibility

--Tom Reynolds


Extensive recent research (1995-97 over 800 man-weeks of survey conducted in the course of Operation Wallacea alone) has shown that the large reefs of Tukang Besi harbor an exceptionally high bio-diversity.

Although only a small number of divers and researchers have had the opportunity to dive in Wakatobi so far, the area is now probably one of the best researched tropical reef areas of substantial size in the world.

Research Highlights: (for detailed reference please see below)

  1. Highest reef diversity indices world-wide
  2. Very high life cover assessment (benthic cover of 76 - 100%)
  3. over large areas) Over 3000 species of fish classified so far
  4. Visibility of 30 - 80m reported (during more than 6 months per year)
This makes the region probably the worlds "epicenter" of marine bio-diversity.

One of the most important reasons is that the last ice age did not affect bio-diversity in this region. Due to its remoteness and extension the negative impact of human pressure on bio-diversity is still limited to isolated areas and species.

For the less scientifically inclined this spells as the most diverse and colorful reefs of the planet with a plethora of beautiful and unusual forms of live to admire.

Combined with a visibility rarely found so consistently.high in tropical waters this makes Wakatobi a world class destination for divers and UW- photographers.

In a move to protect this rich nature heritage, the Tukang Besi reef area Islands whole area has been declared a marine reserve.


General: Quantitative data has been obtained from the May 1997 Progress Report on the 1996 marine Survey of the Tukang Besi (Wakatobi) Archipelago. Southeast Sulawesi, Indonesia of the Operation Wallacea.

The author of this message is NOT related with Operation Wallacea and the authors' views may not reflect the views of the research team in certain aspects. However, due care has been taken to accurately represent the selected data as provided in the accessible written information referenced above.

Please note:
Qualified Wakatobi staff has conducted a combined number of over 20,000 dives in the relevant area and supports the above qualitative views through empirical insight.

Ad (1) - Reef Diversity Index:
The number of species of the family of butterfly fish encountered is used as an indicator for reef biodiversity in the RDI index applied in the survey. The count of over 40 species is the highest count we know of world-wide.

"The family of Chaetodontidae (butterfly fish), represents an important group of coral reef fish. Through evolution, its species have adapted to narrow ecological niches and many are territorial. They can therefore survive in close proximity to each other." Each species is characteristically associated with a particular coral habitat (many are coral polyp feeders) and is therefore directly influenced by the diversity of other reef life, including corals (Reese 1981). In consequence, the diurnal, conspicuous and slow moving chaetodontids are ideally suited as indicator organisms for survey of reef health and diversity." (K.B. Stanzel; H. Newman et al, Operation Wallacea, May 1997)

An other indication for bio-diversity is a count of over 70 different coral genera in Tukang Besi versus a maximum of 20 genera of hermatypic corals encountered e.g. in Caribbean reefs.

Ad (2) Benthic life cover assessment:
"benthic life cover was quantified and qualified for the area covered during swim surveys. Overall a good three quarters (77%) of all surveyed reefs were judged to have 50% or more of live benthic cover. Thirty-nine percent were estimated to have over 75% cover." (K.B. Stanzel; H. Newman et al, Operation Wallacea, May 1997).

Cesar (1996) reports that nation-wide, i.e. over the entirety of the 75,000km2 of coral reefs of Indonesia, only 29% are in good condition with coral covers over 50%."

Please note: certain areas near Wakatobi resort have up to 80% of live coral cover over 75%.(!)

Ad (3) Fish diversity: Source:
(K.B. Stanzel; H. Newman et al, Operation Wallacea, May 1997)

Ad (4) - Visibility 30 - 80m (90 - 240 ft):
Source: own observations of qualified Wakatobi staff in the years 1994 -2005.