Ecoregional Assessment of Biological Diversity in East Kalimantan

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East Kalimantan Ecoregional Assessment: Chapter 2 – Target Ecological Systems The chief threats to Mangrove forests are from conversion to fishponds (tambak); for extraction of wood for various purposes; and for charcoal production. The extensive conversion of mangroves adversely impacts the stability of the coastline, local prawn stocks and pelagic fisheries, and affects the local economy. As a peripheral habitat, mangroves are particularly sensitive to environmental change and pollution. Currently, the removal of riparian vegetation coupled with agricultural development along the lower and middle reaches of many of the major river systems in East Kalimantan is causing excessive sedimentation and significant pollution. This is deleterious to the environment of mangroves, particularly to regeneration success of felled or damaged mangroves (Burbidge and Koesoebiono 1980). It is also extremely harmful to the terminal coastal reef ecosystems fed by the outflow of these large river systems. The recent disasters along the Sumatran region of Banda Aceh and the islands and peninsular regions of southeast Asia that were hit by the tsunami caused by undersea earthquakes in December 2004 exemplified the vulnerability of coastal communities that have removed their protective barriers of mangrove forests to accommodate development and tourism. Those areas that maintained healthy mangrove forests were least likely to have suffered significant property damage or loss of life. This tragic series of events may have been a much needed wake up call to those governments and communities to begin to restore and protect their remaining coastal mangrove forests to buffer them from future repetitions of such horrendous outcomes. The primary threats to Mangrove forest are further described below. • Tambak (fishponds) In recent years, large areas of mangrove have disappeared from the East Kalimantan coastline, particularly in the region of Tanjung Selor and the Mahakam River delta through conversion to fishponds (tambak) where various fish species as well as shrimp are commercially raised. Most tambak in East Kalimantan are found in the Mahakam delta. CIRAD- PT WIN (2002) states that early maps of the Mahakam delta, prepared by the Dutch in the 1940’s, showed it to be almost pristine and to have one of the largest single areas of Nypa fructivora palms in the world. As recently as 1996, the smaller areas of mangroves on the seaward side of the Nypa palms were very much intact, with only very small patches of tambak. However, in 1996, large excavators began to be used to build tambak. Between 1997 and 1999, during the economic crisis in Indonesia, almost all the outer mangrove belt and most of the huge Nypa palm zone was converted to tambak. This conversion process was much cruder than necessary, such that large expanses of mangrove were unnecessarily destroyed. CIRAD- PT WIN (2002) noted the historical importance of this outer mangrove belt to stabilize the coastline. It documents that the coastline is shifting such that many tambak in the outermost perimeter are destroyed, and it argues that the consolidation of the Mahakam delta now very much depends on the narrow inner zone of freshwater mangroves. In addition, the report predicts that if this inner zone is destroyed, 3
East Kalimantan Ecoregional Assessment: Chapter 2 – Target Ecological Systems the shift to the delta would impose a significant economic cost to adjoining agricultural lands. One of the key conservation issues related to the Mahakam delta is the restoration of mangroves through a process of revegetating tambak ‘islands’. Evidence suggests that opening up additional tambak can result in diminishing returns of artificially reared fish and shrimp, relative to the productivity of the formerly pristine mangrove stands (Whitten et al.1987a). Documentation of the economics of tambak is necessary in East Kalimantan. It must be done with consideration of the eventual costs of shoreline loss, property damage, and likely resulting community and political inertia to revegetate these same areas with Mangrove seedlings in the future (See Jakarta Post, 22 July & 28 July 2002). It has been reported that the Mahakam delta freshwater mangroves still harbor viable populations of Proboscis Monkeys and that they are not yet irreversibly damaged. CIRAD-PT WIN (2002) suggests that mangroves could be regrown in the central islands in each tambak and that this would not create a significant loss of income to the local community. Rather, it may consolidate the delta and ensure a longer life for the tambak. • Wood Products Mangroves are exploited for chipwood, raw material for rayon, and building material. Ceriops and Avicennia mangrove trees yield poles and pilings that are durable and frequently used as local house building material. Rhizophora is a favored wood for boat building by locals. Large scale logging of mangroves, mainly Rhizophora, in East Kalimantan for chipwood began on Tarakan Island in 1972. Most mangroves in the Sebuku delta are under concession to be cut and exported for chips. A cutting rotation for mangroves of 30 years duration is believed to be sustainable, but the companies taking mangroves in East Kalimantan frequently have a much shorter cutting interval than this (MacKinnon et al. 1996). Also, it is reported by local villagers, that heavy equipment is used by these companies to root out the mangroves - which destroys any possibility of sustainable harvest. Five local Kabupaten in the northern parts of East Kalimantan, recently (Kaltim Post 16 June 2002) established a local government regulation (perda) to prevent locals from taking mangrove poles for the purpose of house construction. • Charcoal Production Mangroves are used widely for the purpose of charcoal production. They produce manageable-width poles that can be cut to length and easily burned in charcoal ovens and subsequently efficiently packed into bags for distribution and sale throughout the province. It is not known what percentage of all charcoal produced in the province of East Kalimantan or throughout the Indonesian archipelago is derived from mangrove wood. 4
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Ecoregional Assessment of Biological Diversity in East Kalimantan

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