1 Technical Recommendations for Ecological Mangrove Rehabilitation (EMR) in Takalar District prepared by Mangrove Action Project Indonesia as part of the Restoring Coastal Livelihoods Program 1.0 Introduction This report makes technical recommendations for an innovative methodology of mangrove rehabilitation in Tanakeke District. outh ulawesi has seen the wholesale conversion of mangrove forests to aquaculture ponds over the past half century. Numerous ponds, however, are unproductive or abandoned. Programs to intensify ponds use, have not proven successful in increasing long term productivity, or assisting those most in need of assistance, including poor and vulnerable members of local communities and especially women. The rehabilitation of unproductive, abandoned, or disused aquaculture ponds presents an opportunity to increase overall productivity, including fisheries, non-timber forest products, biomass fuel and building material, and ecological services such as carbon sequestration and storage, wastewater treatment and storm and erosion protection. Ecological Mangrove Rehabilitation is a six step approach to restore mangrove areas by focusing on removing disturbance to their natural establishment and functioning. This method prioritizes correcting hydrological flows in and out of the pond, and natural revegetation of the entire range of native mangrove species to an area. This report emphasizes opportunities to demonstrate EMR in abandoned or disused tambak (aquaculture ponds). The EMR approach to tambak restoration can be contrasted with the current predominant approach to mangrove forest restoration in Indonesia (see Fig. 1) which largely consists of direct planting of either propagules or nursery grown seedlings of mostly a single species of mangrove (Rhizophora stylosa bakau ). Plantings usually occur on unvegetated mudflats in front of existing mangroves, along beach fronts, or along narrow fringes of mangroves bordering tambaks constructed in former mangroves and other wetlands. This methodology has been repeatedly documented to rarely establish functional mangrove forests (tevenson et al. 1999; Lewis 2005; amson and Rollon 2008) with most of the plantings not surviving. Figure 1. Alternative approaches to mangrove forest rehabilitation as presented at the Regional eminar.
2 The recommended alternative approach (shown in Fig 2) is the design and implementation of a strategic breaching approach to abandoned or disused tambaks, which limits the amount of excavation necessary while maximizing the hydrologic reconnections with an optimum tidal prism to keep the limited excavated openings functioning over time. This approach is currently being applied on Tanakeke Island in three dusun (Lantang Peo, Tompotanah, Kalukuang). This method has been successfully employed in 25 hectares of abandoned ponds in Tiwoho Village, North ulawesi (see Figure 3) Although ecological and economically, EMR provides a low-cost alternative to enhancing fisheries productivity in the region, there still remain sociopolitical issues to popularizing this method. Pond ownership issues over utilization rights, as well as government reluctance to admit that mudflat planting does not routinely work currently limit opportunity for EMR in Indonesia. Recommendations to overcome these limitations are made in section 3. Figure 2. The strategic breaching model for disused tambaks restoration back to mangroves as presented at the Regional eminar. Figure 3. Time Lapse of EMR in abandoned pond complex at Tiwoho village, North ulawesi. From left to right, photos taken in 2000, 2004 and 2011.
3 2.0 Region and ite pecific Recommendations for EMR in Takalar District Region 1. Laekang Peninsula Historically, much of Laekang Bay had mangrove coverage, but nearly all mangrove was reportedly cleared by WWII. Remnant mangrove peat under andy nearshore substrate show where mangroves used to be established. Recent efforts to plant Rhizophora propagules in this region have largely failed, with limited success in areas where substrate is accreting (seasonal river mouths). Large-scale human assisted distribution of pioneer mangrove propagules (Avicennia and onneratia) in the bay may result in increased coverage and opportunity for non-pioneer mangrove species to grow. There also exist disused and abandoned aquaculture ponds in the bay. The most likely candidate for immediate EMR are the set of ponds on the left of the road when entering Puntondo. This would make an excellent EMR site due to its high visibility by visitors to the PPLH center. Potential for human assisted distribution of pioneer propagules High potential for EMR Figure 4 - EMR Potential around Laekang Peninsula ite 1 - Tambak Besar, Puntondo (Figure 5) This 8 hectare area is targeted for EMR rehabilitation at this time, pending settlement of land tenure issues in both government owned and privately owned sections. Eight pond owners have already pledged their ponds for rehabilitation, but an additional large area, controlled by the District government, still requires negotiation. Our inspection showed some tidal exchange where dikes have been breached and several ponds are now connected to the tides. Various species of mangroves are naturally establishing themselves inside the pond complex, with satisfactory density and growth where dike wall breaching is significant. ome improvement to these connections was discussed in the field. Portions of the site are also showing early succession from halophytic grasses to mangroves. The ultimate connection to the sea under the adjacent road looks somewhat problematic and needs to be checked for clearance and any obvious restrictions to tidal flows on spring tides. A detailed map of the site and characterization of the breaches needs to be completed and phased restoration, management, and monitoring plans prepared and implemented.
4 Figure 5. Empang Besar - Teluk Laekang. Half of this abandoned pond complex is already available for EMR with another half pending negotiations with the Kabupaten government. Initial assessment reveals evidence of natural regrowth, but more breaches in dike walls are needed, along with human assisted propagule dis- ite 2 - Puntondo Lagoon, PPLH This area, located behind the environmental education center, has undergone significant modification and is currently being further impounded by the closure to two of the three natural openings to the sea that allowed for tidal exchange. The third opening facilitated through a seawall has sand accumulating within the lagoon. The flood tide delta appears to be the only free tidal opening at this time, and it too is closing. Complete blockage of all tidal exchange can be expected to occur within 6-12 months. When this happens, the stressed lagoon will be subject to complete die-off of all mangroves if a storm tide, passing cyclone or typhoon introduces enough water into the lagoon, which would drown the mangroves since the natural exits are blocked. This is a common cause of mangrove deaths worldwide. It is understood that the lagoon has divided ownership with competing interests and goals. ome of the owners want natural conditions, some want a functioning tambaks. Not all of these interests can be accommodated without significant stress to the lagoon ecosystem. If all the owners can come together with a science-based management plan, the lagoon has a chance of surviving. Without that, the lagoon in its semi-natural state is doomed.
5 Region II - Tanekeke Island 1700 hectares of mangroves originally grew on Tanakeke. This was reduced to 500 hectares due to the development of 1200 ha of aquaculture ponds. 400 ha of this pond area, is under the jurisdiction of Transmigration Department. The remaining 800 hectares consists largely of abandoned ponds, and ll can be considered for Ecological Mangrove Rehabilitation. The RCL project has begun work in three dusun on Tanakeke Island, Lantang Peo, Rewatayya and Tompotana. Lantang Peo work begun first on a 45 ha rehabilitation project that has returned some tidal flows to disused tambaks adjacent to the village. The oldest of these ponds has had some natural tidal flows for about 10 years and the youngest, approximately a year s worth. Thus the site lends itself to a chronosere study, where specific ponds of different ages can be studied as a substitute for watching and monitoring a few ponds from the time of restoration (i.e., Time Zero) until complete restoration at perhaps Time Zero plus years. Potential for Rehab in (approx 200 ha) Figure 6 - Current and Potential EMR Projects on Tanakeke Island Current EMR projects (approx 165 ha)
6 5 2920" "E "E Tompo Tanah "E Cambayya " MANGROVE ACTION PROJECT INDONEIA RETORING COATAL LIVELIHOOD (RCL) µ 1: Meters DEA TOMPOTANAH PETA DAERAH REHABILITAI DIAGRAM LOKAI P. Tanakeke 5 270" Lokasi 5 280" 5 290" 5 300" " " 5 310" 5 320" "E "E "E "E "E Proyeksi : Transverse Mecartor ystem Grid : Universal Transferse Mecartor Datum Horizontal : Datum World Geodetik istem 84 Datum Vertikal : atuan Tinggi : elang kontur : Keterangan Pintu Air Current Breaches Current Water Flows/Channel Areal diluar tambak (milik personal) Major Breaches >1m Minor Breaches <1 m Condition Of Dyke Walls 5 300" 5 300" High and olid High With Infrequent Breaches Medium and olid (>30-60cm) Medium with Infrequent Breaches Medium with frequent Breaches Low and olid (<30 cm) Low with Infrequent Breaches Low with frequent Breaches Keterangan Riwayat/umber Peta: 1. Citra atelit IKONO Tahun 2004, Google Earth 2. urvey Lapangan eptember "E "E "E Figure 7. Example of Assessment Map to Determine Pond Areas available for EMR. Communities are literally lining up to pledge their ponds for rehabilitation on Tanakeke. The perceived value of restored mangrove forests far outweighs the option of investment in aquaculture. Most islanders partake in seaweed farming as a main livelihood. Their hope for mangrove areas is full restoration for timber, non-timber, fisheries and protection functions. During hydrological restoration, 210 breaches have been made in the dikes, but only a dozen or so may be truly functional in the long term. Many breaches observed have sand accumulations and/or planted or volunteer mangroves that are now blocking flows and will increase that blocking force over time. For this reason, a good GI map locating the 20 or so significant breaches needs to be made, with characterization as to width and depth. These breaches should be watched on a spring tide (high and low) to determine where water flows are going, where restrictions exist, and where improvements and future maintenance of breaches may be needed. A single significant channel with good flows was observed near the village, and this may be the major opening to the system that needs to be maintained with all the other channels connected to it. Only a more detailed examination of the issue will answer this question. The maximum tidal prism for the entire area should be the rehab design goal, and a total area restoration, management and maintenance plan should be prepared in conjunction with the villagers who will ultimately manage the mangroves and harvest the wood products and fish and invertebrates derived from a well maintained ecosystem. ome monitoring has begun and some plantings of Rhizophora stylosa (bakau) have taken place. While the interest on the part of the villagers is to plant and establish bakau cover over all the ponds, this is not a good design for future maintenance of natural tidal flows and maximum fish and invertebrate use. A naturally diverse mangrove community with good representation of all the native mangrove species of the area should be the goal, along with the need for minimal maintenance of the tidal channels. A predominantly bakau plant community with few natural channels will eventually close in on itself and significantly reduce the fish and invertebrate use (and potential harvest) of the restored plant community over time.
7 The human assisted distribution of pioneer mangrove species such as Avicennia and onneratia, which have mostly been lost from the Tanakeke system, is a suggested future action. Work in Tompotana is very similar to that on Lantang Peo. trategic breaching to form several, self maintaining tidal creeks is crucial. Work in Rewatayya differs somewhat. In this region, dike walls are already deteriorated, and mangroves are growing back sufficiently in several areas. Areas where mangroves are not growing, are suggested for colonization by pioneering mangroves. The Department of Forestry has recently planted Rhizophora propagules in a large area of disused ponds, but this action is not recommended in the future. There are adequate natural Rhizophora seedlings in nearby forests. As stated above, if the dense planting of Rhizophora establishes itself and grows, it will eventually clog the flow of newly forming tidal creeks, and to grow in a dense stunted manner, with significantly lower overall biomass. Region III Takalar Lama This region has the largest concentration of aquaculture ponds in Takalar District. It differs than Tanakeke or Laekang, in that is a river dominant system, with abundant Nypa palm historically. Ponds are still actively managed in this region, but some ponds are abandoned. The RCL project is currently mapping out pond use and ownership, looking for areas of significant abandonment for EMR. EMR in this region would likely also involve the direct planting of Nypa fruticans, to help develop potential industry on non-alcohol Nypa based products. ocial business investors are already interested in this potential. uccess is likely in this region, evidenced by the growth of Nypa and other mangrove types in ponds abandoned within the past 10 years (see Figure 8). Figure 8. EMR Potential in Takalar Lama. Areas highlighted in yellow dots have already undergone natural revegetation, primarily with Nypa fruticans. Areas in white have potential for EMR (above). Big Tree Farms of Bali is interested in developing high end Nypa Palm ugar as a sustainable livelihood option for local communities (bottom right).
8 3.0 Cost and Benefit The process of EMR from a project management aspect can be seen in figure 9. ocial organizing is a main expense in the process, taking at least half of the required funds. This can usually be costed at 4 million rupiah per hectare for a hectare site. Hydrological amendment, if necessary, also costs approximately 2-4 million rupiah per hectare. Finally, if pioneer propagules are needed for dispersal, an additional 500,000rp to 1 jt. rupiah per hectare may be required. All told, the cost of EMR ranges between million rupiah per hectare. In terms of benefit, it is predicted that successful EMR restores 75% of functional fisheries value after 5 years. 100% may be reached by years. Mangroves are considered to have a fisheries value of between million rupiah per hectare per year, and an overall value of 120 million rupiah per hectare per year (Constanza, 1997 and Ronnback, 1999, Barbier, 2000). If 75% of fisheries value alone is reached at 5 years (minimal 17jt per hectare per year), EMR easily pays for itself, and begins to provide significant benefit to local communities. Figure 10. Nilai Bahan dan Jasa Lingkungan dari Hutan Bakau yg Utuh
9 Figure 9 - The Project Cycle applied to EMR 4 Appraise and elect ites, based on social, economic and ecological factors 3 Assess Modifications of previous mangrove system preventing natural secondary succession 5 Design implementation and monitoring plans, promoting natural seedling recruitment The ix (6) tep Ecological Mangrove Rehabilitation (EMR) Method Project Cycle Version 2 Assess Hydrologic Patterns controlling mangrove distribution, establishment and growth 6 Implement rehabilitation and monitoring analyze data & communicate results 1 Assess autecology & community ecology (reproduction, distribution, establishment) TART clarify intention/ mission of EMR ITERATE use results to adapt and learn hort Training Long-training/ Initial Implementation caling-up (on-site or using experienced community members as trainers at new sites)
10 4.0 General Recommendations for EMR Practitioners in Indonesia A. The failure of the mudflat and beachfront plantings of primarily bakau to survive over time, or if partially successful, provide minimal ecological functions, needs to be documented if possible. The cost per successful hectare of mangrove establishment also needs to be calculated and reported. Use of a similar unsuccessful technique (Riley Encasement Method) in Florida (Johnson and Herren, 2008) was shown to ultimately cost nearly UD$1.5 million per successful hectare where it was shown to partially work. This kind of information has been used to move government agencies towards more ecologically sound and cost effective methods of mangrove restoration in Florida. B. The success of EMR and strategic breaching to establish more ecologically sound and cost effective mangrove rehabilitation sites needs to be similarly documented. The ongoing work at Tanekeke Island is particularly important in this regard. C. An easily accessible and viewable EMR restoration site needs to be established on the mainland. Even if small, the availability of such a site for viewing by larger numbers of government officials, academics and students is important in educating everyone about the value of the EMR approach. D. A short Indonesian written publication with good drawings that describe the difference between mudflat/beachfront plantings should be distributed. EMR should be prepared to educate everyone about the issues. E. Further local workshops should be funded and conducted to provide EMR training to all those who desire to learn how it works and how to undertake this type of restoration. 5.0 References Barbier, E.B., Valuing the environment as input: review of applications to mangrove-fishery linkages. Ecological Economics, (1): pp Costanza, R. and Folke, C Valuing ecosystem services with efficiency, fairness, and sustainability as goals. In G.C. Daily (ed.) Nature s ervices, Washington D.C. Island Press. Johnson, LK, and LW Herren Reestablishment of fringing mangrove habitat in the Indian River Lagoon. Report to the t. Johns River Water Management District. 161 pages. Lewis, RR Ecological engineering for successful management and restoration of mangrove forests. Ecological Engineering 24(4 I) Lewis, RR Technical Recommendations Report from R. R. Lewis III for July 13-22, 2011, EMR in outh ulawesi. RONNBACK, P., The ecological basis for economic value of seafood production supported by mangrove ecosystems. Ecological Economics, (2): pp amson, M, and RN Rollon Growth performance of planted red mangroves in the Philippines: revisiting forest management strategies. Ambio 37(4): tevenson, NJ, RR Lewis, and PR Burbridge Disused shrimp ponds and mangrove rehabilitation. Pages in An International Perspective on Wetland Rehabilitation, WJ treever, (Ed.). Kluwer Academic Publishers, The Netherlands 338 pages.