The Sampela coral reef wall runs for 200 metres orientated to the northeast, directly in front of the Bajo village after the sand flats. This wall has been eroding, principally due to the process of sedimentation. If this degradation continues the coral reef wall could potentially disappear leaving no protection for the Bajo village against storm action. In addition the lack of coral deters fish numbers and fish biodiversity away from the reef, this means the Bajo could have a shortage in fish availability on which they depend. The Kaledupan coral reef, which is situated very close to the Sampela wall, is a pristine reef and has suffered very little damage; hence this reef provides a good comparison showing how the condition of a reef would ideally be. The degradation of the Sampela wall is probably partly due to the proximity of the Bajo village, since pollution comes from their waste and the sand flats are continually cleared by them. In addition the extensive clearance of mangroves on Kaledupa to the rear of the Bajo village means sediment can flow freely through. The degradation is also probably due to natural factors such as weather and temperature effects on the reef. Addressing this problem requires primarily a survey underwater of the degree to which the Sampela wall has eroded, to see how urgent action is needed and to determine what preventative measures, if any, can be taken.

• To find out how and why erosion of the wall is occurring.
• To show the physical structure of both the Sampela coral reef wall and the pristine site at Kaledupa in order to show the contrast.
• To consider potential management techniques that could prevent 1) Erosion of the wall 2) Damage to the Bajo village.
• Collection and analysis of sediments in order to assess the impacts of sedimentation.
• To look at coral rubble slips on Sampela wall in order to determine how much material is lost through slippage.
• To determine the implications for the Bajo village if this wall disappears.
• A comparison of the Sampela wall to the pristine site of Kaledupa, with the intention of having 5 stations at each site.
• To determine contributing factors to the degradation of the Sampela wall (other than sedimentation and where it comes from e.g. Pollution from the Bajo village itself.

• Collection of loose material into coral rubble traps placed along the side of the reef.
• Collection of some background information concerning the Bajo community.
• To construct 5 vertical transect lines at each of the sites to be studied.
• Placement of 3 sediment traps at the site on each transect line, placed down on a 5-day cycle.
• Obtain information on the area such as the sand flats and mangroves to determine other contributing factors to degradation of the wall.
• Complete complexity measurements up the complete set of transect lines to aid the topography (mapping) of both reef walls.
• To measure the gradient / profile of both reef walls.
• Collect visibility data using a Secchi disc.
• Collect water samples to do a nutrient analysis.
• Collection of biological data up the transect lines concerning coral growth forms and percentage cover.

Five 16m transect lines were laid running vertically up the Sampela reef wall and the Kaledupa reef wall. The lines run up the substrate from approximately 12m depth up to 4m depth, and each line was segmented into 2m sections. These five transects are placed at buoys 1 & 2 at Sampela and at buoys 1,2 & 3 at Kaledupa. The exact positioning of the transect lines was recorded by GPS.

Three sediment traps were placed on the substrate to the immediate right of each transect base (12m depth) at each station at Sampela and Kaledupa. After a period of 5 days the sediment traps were then removed and a new set put down in their place, until 3 full cycles had been completed. Each sediment sample was then filtered before analysis.

The surveyor progressed up the transect line collecting biological data covering sections 2m by 3m up the length of the transect line. The percentage of growth forms present was noted which included the following corals; branching, encrusting, sub-massive, tabulate, massive, mushroom, foliose. In addition the percentage of coverage type was assessed to include; live coral cover, dead coral cover, soft coral cover, algae, rock, rubble, sand.

Commencing at the base of the transect upwards physical data was collected. Firstly the complexity of the wall was ascertained using a flexible metal chain. This chain was placed horizontally across the substrate at each of the 2m section marks, then the surveyor measured the length from one end of the chain to the other. In order to collect the profile data, measurements were taken at the same points (i.e. at each 2m mark). A metre rule was made with plastic piping attached containing a bubble, effectively enabling the rule to be held horizontally level against the substrate with a greater accuracy. The metre rule was positioned with one end against the substrate and the other into the blue. The metal chain was then dropped from the end of the metre rule to where it hit the wall below and this length was measured and recorded.

In order to collect information concerning amount of rubble falling down the wall, coral rubble traps where placed by affixing baskets on the coral slips against the substrate using wooden stakes. These were placed on main coral rubble slips at about 10m depth along various places on the Sampela wall.

Nutrient information was collected by taking water samples at a depth of 1m at both Kaledupa and Sampela. Three sample bottles were used each time.

Using the data that I have recorded into Microsoft Excel I will create scatter graphs and bar graphs to show the relationship between variables. I will also use the geographical statistical package Minitab in order to show statistical information. The physical data I collected such as the complexity and profile measurements I will use to create a model of the reef walls. Relationships could be shown between coral cover and depth, complexity at various depths comparing Sampela and Kaledupa, profile changes and the differences between the eroded and the pristine site. Using the results I will get from the sediment data (which have been filtered and will be weighed and analysed back in the UK) I intend to show the relationship between amounts of sediment at Sampela and Kaledupa. I will also have photographic evidence of the sites and this will back up the models/maps of the two reef walls. The most important comparison is perhaps the percentage of live and dead coral cover differences between Sampela and Kaledupa, since this will show the great degree to which the Sampela wall has been damaged.

Once the sediment samples have been analysed, I expect that there will be a greater amount of sediment present at the Sampela sites than the Kaledupan and that the material will be of a different type. There should be a much greater complexity at Kaledupa than at Sampela since there are much larger corals there, because they have been allowed a longer life span. The profile of Sampela tends to be a much gentler gradient than at Kaledupa where the reef wall is occasionally vertical. Percentage of dead coral cover at Sampela is evidently greater than at Kaledupa, however I also expect that at both sites there will be a similarity that live coral is greater at shallower depths. It is expected that the Bajo people know nothing about the degradation of this coral reef since a good majority of the people are illiterate. However, it may be possible to explain the effects the lack of coral has on biodiversity and fish stocks since this is such an important part of their livelihoods.

A report entitled  ‘Implications for a coral reef collapse for a Bajo Village in the Wakatobi Marine National Park in Indonesia' will be produced by Lucinda Markham, University of Portsmouth by June 2002.