Togean Biodiversity Review
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SUMMARY of TOGEAN BIODIVERSITY CONDITION Conservation International Indonesia, Palu-Office, Central Sulawesi I. INTRODUCTION Togean Islands occupies the central portion of Tomini bay, stretching over a distance of about 90 km. This archipelago contains 66 islands of which Una Una, Batudaka, Togean, Talatakoh, Waleakodi, and Waleabahi are the largest. Una Una, a recently active volcano, is relatively isolated, situated about 30 km north of Batudaka. The land area of the Togean group covers about 755 km2, mainly consists of mountainous or hilly terrains. The maximum elevation on the six islands ranges from 354 - 543 m. Six main ethnic groups are represented by Bajau, Bobongko, Togean, Saluan, Bugis, and Gorontalo as well as some other small ethnic groups such as Sangir, Minahasa, Java and Chinese, with total population more than 30,000. In general, except the Bajau which is strongly depending on marine natural resources, the other the islanders are farmer (especially for coconut plantation) which are only using their extra times for fishing. The other small groups compose of teachers, trader, and government staffs. Togean Islands supports rich diversity both marine and terrestrial. In terrestrial, some endemic species can be found in Togean. Red knobbed hornbill (Rhyticeros cassidix), tarsiers (Tarsius spectrum), Wallacea deer-pig (Babyrousa babirussa) and Sulawesi cuscus- bear (Phalanger ursinus) are the examples of endemic species to Wallacea region; while the Togean’s endemic are represented by the togean macaque (Macaca togeanus) and togean monitor lizard (Varanus togeanus). Togean archipelago also keeps marine biodiversity richness which consists of four types of reefs ever known : fringing reef, barrier reef, patch reef, and atoll. Based on the Conservation International Indonesia’s (CII) Marine RAP survey conducted in 1998, biological diversity is relatively high in the Togeans and comparable with Calamines groups in Philipine, Milne bay in PNG, or Komodo Islands in Indonesia. The survey recorded 262 corals, 596 reef fishes, and 555 species of mollusks belong to 103 families, 336 gastropods, 211 bivalves, 2 cephalopods, 2 scaphopods and 4 chitons. Wallace et al. (2001) revealed 91 species of Acropora were recorded within the Indonesian archipelago while the greatest number of species was recorded in the Tomini Bay (78 species). Many of the sampling points within the Tomini Bay were undertaken in Togean Islands. Beside the Togean’s endemic species Acropora togianensis (that was already described in 1998 by Wallace & Wolstenholme), during the survey also recorded 2 species new to science. The diversity and unique assemblage of the region may be due to the unusual combination of habitat types, which are sheltered from the two opposing monsoonal systems that influence north and south Sulawesi Sea. Unfortunately, the richness of the Togean are under threat by destructive activities, both on terrestrial and marine. Clearing native forests for agriculture and farming, villages expansion, illegal logging, and over exploited of threatened species occur in many places. In the same time, destructive fishing practices such as blast fishing, poison, and fishing pressure by only targeting to certain fishes considerably falls into critical stage of sustainability marine resources. Table 1. Population and data of area of Togean Islands (Source: Poso Regency Statistic, 2000) District (Kecamatan) Village (Desa) Area (km2) Population Una Una 21 515,19 19.022 Walea Kepulauan 16 240 12.201 II. BIODIVERSITY AND CONSERVATION PROBLEMS MARINE BIODIVERSITY CI Marine RAP survey 1998 in Togean was collecting 262 coral species on 25 sites. The Togean’s endemic Acropora togianensis were found in 11 sites with common and conspicuous on many. A total of 541 species of mollusks belong to 103 families were recorded. There were found 596 species of fishes in Togean Islands which is consisting mainly of species associated with coral reefs. At the 25 survey sites, 142 species of coral fishes were observed belongs to 37 genera. In general, atolls were the richest of major habitats for fish with 200 species per site. Table 2. Top 10 sites for general reef condition (Source: MRAP 2001) Coral Fish Relative Site No. Location species species condition 13 Northern-east side Una Una Island 67 230 Good 24 Reef between Waleabahi and Talatakoh Island 93 124 Good 9 Kadidiri reef 87 169 Good 20 Southern Batudaka Island 83 216 Good 16 Western Batudaka Island 62 208 Good 12 Northern-east side Una Una Island 69 161 Moderate 7 Kadoda reef, Northern Malenge Island 68 181 Moderate 15 Pasir Tengah Atoll 84 202 Moderate 10 Northern-west Kadidiri reef 50 208 Moderate 21 Pasir Batang Reef, off Kabalutan Village 84 174 Moderate Most of the sites mentioned above were functioning as fishing grounds as well as tourist diving sites. In general, illegal fishing practices, anchors, and over exploited at top 10 sites will threaten corals and fishes biodiversity. Marine RAP survey conducted in 1998 identified damages due to blast fishing were observed at 86% areas. According interview with villagers of Kadoda, the Kadoda reef (site 7) is main target of both poison and blast fishing practices. Up to now blast fishing still happen at the Kadoda reef. Table 3. Average percentage of live coral covered at top 10 sites for general reef condition (Source : Marine RAP, 2001) Site No. Location % Cover 13 Northeast side Una Una Island 58.4 24 Reef between Waleabahi and Talatakoh Island 56.3 9 Kadidiri reef 52.0 20 Southern Batudaka Island 42.0 16 Western Batudaka Island 36.6 12 Northeast side Una Una Island 58.3 7 Kadoda reef, North Malenge Island 55.0 15 Pasir Tengah Atoll 57.6 10 Northern-west Kadidiri reef 42.0 21 Pasir Batang Reef, off Kabalutan Village 44.6 THREATS Although live corals cover were apparently high throughout Togean, there was evidence of reef degradation at many sites. The reef of Southern Waleabahi Island has clearly been damaged by human activities, particularly by blast fishing. It was showed by the high percentage of Hard coral of Togeans rubble and recently damaged corals. Dead coral colonies on (G. Allen. MRAP 1998) reef are probably due to a high concentration of suspended sediment. Agricultural development in forest areas, no doubt has contributed to the soil erosion and results sedimentation to the reefs, while harbors development as well as boat anchor contributes to the coral damage also. 1. Natural threats Coral reef, which contains thousands of independent species, can be adversely affected by natural events. Powerful tropical storms and hurricane may break apart shallow water branching corals. Heavy and prolonged rainfall running off nearby large islands and mainland’s coasts may cover reefs with sediment and dilute salt water with large amount of fresh water. Increasing of sea temperature creates widespread occurrence of coral bleaching, due to the loss of coral’s symbiotic algae, zooxanthellae. Coral could recover as long as the high sea temperatures are happening in a short time, but not prolonged. At low tide, some coral reefs on Kabalutan and Teluk Kilat will appear at sea surface while extended sun exposures would make corals dehydration phenomenon. Crown of Thorn Starfish can feed on corals voraciously. In 1996 there was a population outbreak of this species in Togean. During the outbreak, the presence in large numbers of this species converted coral reefs into a mass of dead coral skeleton in only few weeks. The starfish dispersed almost in all over Togean Islands. 2. Destructives fishing practices • Poison (both traditional poison tuba, and potassium cyanide). The substance used by local fishermen is similar with the commercial product known as rotenone. It is derived from the root of derris plants (Derris spp). The roots are crushed and the resultant milky is dispersed into the sea water. This substance causes constriction of the gill capillaries. A mild dose only makes the fish stunned while prolonged exposure usually kills the fish. A “modern” technique involves is the use of potassium cyanide (KCN), which not only affects fishes but also corals and other invertebrates. Species targets are Napoleon wrasse and groupers. • Blast fishing. Known also as bomb fishing are common in Togean. Fishermen generally make their own explosives by stuffing fertilizer and match-head powder into a bottle. A more modern and sophisticated method is using a simple detonator attached to a battery with a wire. Dynamite is often used to catch schooling fishes or concentrated reef fishes. Economic pressure frequently forces fishermen to abandon traditional fishing methods in favor of destructive techniques such as blasting and poisoning. Many of local people mentioned explosive is mainly used by specific villagers of Kabalutan, Milok, Pulau Papan, Salaka, and Panabali; which indirectly refers to Bajau community. But, it was also found villagers of Pautu, Malenge, Tumbulawa and other villages, which means blast fishing not merely practiced by Bajau but also another ethnic groups. The local fishermen claimed that traditional methods are no longer economically benefiting and they are forced to use explosive and poison in order to survive. Fishermen have been forced to increase catches in order to keep pace with inflated prices for essential commodities. Based on Hutabarat (2001), there were some factors cause people use explosive to catch fishes : Economic opportunities, while comparing to the traditional practices explosives can open opportunities to get more fishes quickly to fulfill the high demand on consumption fishes Competition with outsiders who have been using destructive techniques in harvesting marine natural resources which result more fishes than using traditional techniques Socio-psychological factor of the Bajau communities : - Bajau communites are blammed as well as labeled by another groups as bombers and reef destructor. Eventhough the Bajau is keeping suspected for each any sound of exploding heard without trying to find out who really does. Keep continuing destructive activities might be as a dissapointment expression of Bajau community group against others.