Reef Regeneration

Tioman Island (Malaysia)

Pulau Tioman lies approximately 30 miles north-east of the town of Mersing on the East Coast of West Malaysia. The island is roughly pear shaped with a length of about 25 miles and a maximum width of 9 miles. The island is granitic in nature and is formed from a long extinct volcano. The interior rises steeply from the sea to a maximum height of 9,000 feet and is mostly uninhabited virgin jungle. The population of about 2500 is scattered at various points around the mostly rocky coastline and most of the settlements are only accessible by boat or footpath. The only road suitable for cars is about 4 miles long and links the small airport to the main town of Berjaya, where there is a sandy beach and a large resort hotel. Pulau Tioman was the location for the filming of the 1958 classic musical "South Pacific".The Tioman authorities have made strenuous efforts in the past few years to improve the cleanliness and general state of the island. Since the author was last there 3 years ago when conditions were poor to fair, the beaches and adjacent areas are now considered to be very good or excellent in terms of general cleanliness. The authorities have also declared a two-nautical mile zone from the seashore to be a Marine Park. Collecting of any form of sea life is prohibited as are fishing of any description, anchoring of boats (not universally observed despite the fact that mooring buoys have been provided) and use of jet skis (still seems to be permitted in the main resort area).

Reef Regeneration

Reef regeneration on Pulau Tioman takes two forms. Firstly there are the regulations to protect existing reefs as outlined above. These seem to be having positive effect. The natural reef at Air Bintang, while nowhere near as diverse as some other reefs on the Tioman Archipelago, shows the effect of the regulations that have been brought in. The places where boats had dragged their anchors in previous years were now being covered by new coral growth, mainly acroporas, both staghorn and plate types. Interestingly, while most of the older staghorn acropora was brown, the younger pieces were often bright green in colour. The author last visited this reef three years ago and while no attempt was made to produce a definitive list of fish species observed, there did seem to be a wider variety of species, although not in great numbers. The reef at Air Bintang is relatively small, estimated at approximately three quarters of a mile long by 140 yards wide, and of only mediocre quality. However many species of fish commonly kept in aquaria were observed including seven species of butterfly fish and three species of clownfish Amphiprion percula, A clarkii and A. akallopsis together with host anemones. Other damsel fishes were also present, although apart from sergeant majors (Abudebuf saxatillis) these latter were not present in the large shoals that normally grace reefs elsewhere. A number of Crown of Thorns starfish (Acanthaster Planci) were and their damage to coral was obvious but limited. The second form of reef regeneration on Pulau Tioman is more positive in nature and seems to be very successful. This has taken the form of placing concrete supports on the sea bed to form a base for coral encrustation The largest collection of these is north of the natural reef at Air Bintang and is at a depth of 25 metres. This was not visited by the author. There is however a smaller experiment, adjacent to the Marine Park Research Centre at Tanjung Mesoh. Much of this can be observed from the adjacent pier, or better by snorkelling. The concrete support for coral encrustation takes the form of circular slabs of concrete, approximately one metre in diameter, supported on three concrete legs, which have longitudinal slots in them. The circular slabs also have three curved pieces of concrete projecting upwards. These latter are also slotted These concrete structures are at varying depths, estimated to be between 5 and 15 metres at high tide. Although the project is less than 3 years old, there is already considerable coral growth on virtually all the supports. Corals are principally acroporas, both staghorn and plate forms. The largest corals measured were:

• Brown staghorn acropora = 18 cm
• Green staghorn acropora = 20 cm
• Plate acropora colony = 30 cm

The branched corals seemed to be largest in the shallower water (approximately 5 metres depth), while the largest plate coral was found in about 8 metres of water. Small fishes are also using the slotted support legs as hiding places. Temperature measurements made in the water surrounding the experiment were consistent at 30 degrees centigrade. There was no measurable difference at several points of measurement over the experimental area and these figures exactly matched those over the nearby natural reef at Air Bintang. These measurements were made at the end of February, which is the end of the cool/rainy season in this part of the world, although whether this has any effect on water temperature is unknown.

Conclusion

Efforts to improve existing reefs and generate new ones on Pulau Tioman are showing favourable results. In particular, the encouragement of new coral growth on artificial supports looks particularly promising.

By Brian Windibank