Mangrove Restoration after the 2004 Tsunami in Aceh, Indonesia

1.         Introduction

The Boxing Day earthquake, with a moment magnitude of 9.3 on the Richter scale, was the largest ever recorded in human history, caused a tsunami in Aceh and Southern Thailand (Levy and Gopalakrishnan, 2005), and killed at least 288,828 (Ontowirjo and Mano, 2005). In the Aceh area, the tsunami flooded almost 900 km2 of coastal land (Iverson and Prasad, 2007) and devastated 175 km of its coast (Liew, 2010).

This report reviews the mangrove / coastal vegetation restoration in Aceh after the 2004 tsunami, whether it has been successful or not, and suggests recommendations to improve the efforts.

1.1. Geography

Aceh is a province as well as a special region in the Republic of Indonesia, an archipelago country. It is located on the north-western tip of Indonesia, between latitudes 2o – 6o North and longitudes 95o – 98o East (Aceh in Figures, 2010). Aceh Province is approximately 58.375,63 km2; the land is primarily used for forestry (3.523.817 ha), plantations (691.102 ha) and industrial purposes (3.928 ha).

1.2. Climate

Temperatures in Aceh fluctuate between 25.5°C – 27.6°C, with the highest is usually recorded in May and the lowest in August, November and December (Aceh in Figures, 2010). Air humidity ranges from 73.2% to 91%, with the highest in September and December and the lowest in January. Overall, Aceh has a tropical rainy climate.

1.3. Biodiversity

Unfortunately, there is no comprehensive study yet about biodiversity in the whole area of Aceh. Two studies that can be used to represent Aceh’s biodiversity are marine biodiversity in Indonesia and ecosystem in Leuser, west Aceh.

Indonesia, with 51,020 km2 of coral reefs and 25,000 – 42,550 km2 of mangrove forests, is one of the marine biodiversity centres (Cochard et al., 2008). Secondly, Deschamps (2001) reported about the Leuser ecosystem, an area in Aceh with significant high tropical biodiversity, which is the last place on earth where elephants, rhinoceros, orang-utans and tigers are found together in the same area. The range of biodiversity in the Leuser ecosystem shows 45% of the total estimated number of plant species in the West Indo Malayan region, 85% of the bird species in Sumatra, and 54% of the total land animal species in Sumatra Island (Wibisono and Suryadiputra, 2006).

1.4. Human history

According to Perret (2007), the first evidence of human habitation in Aceh is from a site near the Tamiang River. Stone tools were found at the site. Archaeologists believe this site was first occupied by human inhabitatant around 10,000 BC.

2.         Condition of Mangrove Forest in Aceh before the 2004 Tsunami

Mangrove is a salt-tolerant group of forested wetlands that dominate the intertidal zone, such as estuaries and lagoons of tropical and subtropical coastal landscapes. The plants are unique for five reasons (Wetlands International, 2005). First of all, they have breathing roots, an adaptation characteristic, to provide air even when they are flooded with salt water during the high tide. Secondly, some mangrove plants can exclude salt from their leaves or roots. Others can store the salt in their leaves (vacuoles) and shed it periodically. Furthermore, mangrove plants can also store freshwater in their leaves. Most of their leaves have shiny and waxy surfaces to reflect the sun light. As a result of this, the loss of freshwater is decreased due to the low leaf temperature. Fourth, mangrove use viviparity as their seed germination. Finally, the plants have prop and stilt roots which give extra support to the tree balance on unstable soils because of tidal flows.

The common mangrove formation in Aceh was reported in Figure 1 (Wibisono and Suryadiputra, 2006).

3.         Cause of Mangrove degradation

In Aceh, some tsunami waves in 2004 were recorded as reaching heights of more than 20 m at the shoreline and speeds of up to 800 km/h (Cochard, et al., 2008). These natural disasters caused destruction along almost the entire Aceh coast.

According to Wibisono and Suryadiputra (2006), there are two ways in which the tsunami damaged the coastal ecosystem:

  1. Direct mechanism: the tsunami swept the coast and destroyed mangrove forests, Casuarina stands, and coconut trees by its energy. This happened directly and extremely quickly caused severely damaged vegetation. In the worst areas, mangrove trees were even uprooted by the waves.
  2. Indirect mechanism: the sea water with high salinity, which brought by the tsunami, caused coastal vegetation stressed, dry and finally die. The trees which died in this mechanism were usually still stand well as a whole.

Besides a catastrophic natural disaster, mangrove in Aceh had already suffered degradation, mainly along the east coast. The main causes were the development of shrimp ponds, oil palm plantations, and the using of mangrove trees for charcoal (Wibisono and Suryadiputra, 2006).

4.         Condition in Aceh after the 2004 Tsunami

The 2004 tsunami caused tremendous destruction in almost all of the existing formations and types of vegetation in the west coast. It was triggered by a great earthquake which changed the landscape on the west coast of Aceh and the islands of Simeulue and Nias.

There was a remote sensing study to indicate the effects of tsunami in Aceh. It is said that 99 % of aquaculture ponds, 88 % of mangrove, and 76 % of beach forests were affected with the tsunami (Chen et al., 2005). The difference of the impacts on mangrove and beach forests may be because of their differences in rooting morphology, soil substrate, hydraulic exposure, and stand density and structure (Cochard et al., 2008).

4.1. Landscape change

According to Wetlands International (2005), subsidence happened in Aceh’s west coast resulting in the advance of shoreline between 100 to 200 meters inland. On the other hand, part of Simeuleu Island was lifted up by 2 m, exposing the coral reef and killing the mangrove forest. This damage also happened in the north part of Nias Island. Generally, the Aceh’s coast was eroded back about 500 m except at headlands (Liew, 2010).

4.2. Mangrove degradation

Degradation in mangrove forests may also means the loss of seed production because of many mature trees was lost and died. Wibisono and Suryadiputra (2006) estimated the percentage of mangrove damage in 5 biggest districts in Aceh was:

  1. Aceh Besar 100% (approximately 26,823 ha)
  2. Banda Aceh 100% (<500 ha)
  3. Pidie 75% (17,000 ha)
  4. Aceh Utara and Bireun 30% (26,000 ha)
  5. Aceh Barat 50%, (14,000 ha)

4.3. Coastal vegetation degradation

Coastal vegetation is all vegetation types and formations which grow in dry land in coastal area, including beach forest, rubber plantation, coconut plantation, cultivated gardens, Barringtonia formation, and Casuarina forest. EU Joint Research Centre in Wibisono and Suryadiputra (2006) estimated 80,795 ha of coastal vegetation was damage because of the tsunami.

5.         Restoration efforts

Mangrove restoration means re-introduction and re-establishment of native mangrove species assemblages to sites that can support them to be developed into mangrove ecosystems which perform similar functions as closely as possible before the disturbance occur (Wetlands International, 2005 ; Yap, 2000).

The objective of the restoration is  to re-establish mangrove / coastal vegetation habitats (structure) and their functions, such as coastal protection, contribution to fishery production, and enhancement of aesthetic quality of the landscape (Wetlands International, 2005). Unfortunately, there are no specific restoration goals in periodic of times. This may be happened because the restoration was done by many institutions which not well-coordinated yet.

Recent views said that natural regeneration is still the best way of restoration (Yap, 2000). However, this may be inadequate in Aceh because the huge damage which has been caused by the magnificent tsunami. As a result, artificial regeneration through the planting of seeds, propagules or seedlings from different locations, should be done.

The restoration was implemented with the planting of mangrove and other coastal vegetation in areas which have been damaged by the tsunami. The planting was first initiated by several International NGOs; such as Oxfam, Islamic Relief, and Mercy Corps, through ‘Cash for work’ program in April 2005 (Wibisono and Suryadiputra, 2006). This program encourages community to plant mangrove and other coastal species in several locations in Aceh. Then, The Department of Forestry through its Watershed Management Service in Aceh began the planting of mangrove in Lham Nga village-Aceh Besar, attended by Indonesian Minister of Forestry, MS Kaban. In 21 November 2005, BRR, Agency of Rehabilitation and Reconstruction in Aceh and Nias, officially launched the ‘Coastal Re-greening Project’ in collaboration with Wetlands International – Indonesia Programme and WWF-Indonesia (Wibisono and Suryadiputra, 2006). Since then, many other institutions, both government and non-government, have been join in the rehabilitation.

Mangrove species were usually planted in brackish aquaculture ponds, degraded mangrove habitat, and along river banks. Unfortunately, mangrove was also found to be planted in unsuitable places, such as deep sandy beaches and dry land (Wibisono and Suryadiputra, 2006).

Based on the calculation, mangrove density was 76 times higher than other coastal vegetation’s. This happened because although the areas that suitable for mangrove were not much available after the tsunami, many implementers preferred to plant mangrove than other species due to the cost. Another problem was activity reports. Only a small proportion of the implementers have reported their activities, including the numbers of their actual planting, while the others not. There is an opinion, may be because, for certain reasons, some of them cancelled planting or reduced the number of seedlings sharply (Wibisono and Suryadiputra, 2006).

6.         Level of Restoration Success

To determine whether or not the mangrove ecosystem has been restored successfully, there are criteria to value the level (Ellison, 2000). These include characteristics of vegetation structure, levels of primary production, composition of associated animal communities, and hydrology.

In my opinion, the certain degree of rehabilitation success in Aceh is not known yet due to the lack of data and information. Many implementers do not do monitoring, so they do not know how many seedlings which have survived. Based on field observation, the survival rate of mangrove species is 40%-60%) and other coastal species is 20%-50% (Wibisono and Suryadiputra, 2006).

7.         Recommendations

7.1.  Selection of appropriate species and planting sites

Local species should become top priority and alien species should be avoided because it can disturb the equilibrium of the ecosystem. If the planting site is muddy beach, mangrove vegetation, such as Rhizopora sp. should be selected. Which particular species of mangrove that would be planted depend on specific characteristics of the substrate, in particular the depth of the mud, the condition of the tides, and the distance from a river. On the other hand, if the planting site is sandy beach, other coastal vegetation species such as Sea pine (Casuarina sp.) must be chosen.

7.2.  Biological indicators for selecting planting site

Local plant or animal species can be used as a biological indicator of the rehabilitation suitability in the specific area (Wibisono and Suryadiputra, 2006). For example, the mud skipper (locally known as Glodok or Tembakul) is an animal indicator of suitable sites for planting the mangrove because the creature likes a muddy substrate with periodic flooding.

7.3. Development of Decision Supporting System for rehabilitation site selection

Decision Supporting System (DSS) is a tool which can be used to help selecting good and appropriate rehabilitation sites (Wibisono and Suryadiputra, 2006).

Based on the chart, even though the land is bio-physically suitable, there may be other factors that could make it becomes an unfeasible site for rehabilitation (Wibisono and Suryadiputra, 2006). For example, it may be too remote from the community which can make the rehabilitation efforts are unsuccessful. If the constraining factors are greater than the supporting factors, the activity should not be undertaken. If, in contrast, the supporting factors outnumber the constraints, the activity has a good chance of succeed and therefore, can be undertaken.

7.4. Improvement of active community participation, raising public awareness, and coordination among stakeholders

There is a view that active community participation is a key to success in ecosystem restoration (Yap, 2000). Unfortunately, their role and participation is still very limited. In all the previous rehabilitation activities in Aceh and Nias, the community has been involved only as planters and porters, and their involvement has automatically ceased when the planting and distributing are finished (Wibisono and Suryadiputra, 2006).

To be successful, the community must be involved actively in the whole spectrum of rehabilitation activities, starting from planning, planting, monitoring and evaluation. Through this mechanism, they will have sense of belonging to rehabilitation activities. Furthermore, it will be much better if there are efforts to raise public awareness of the importance of mangrove and coastal vegetation to the environment.

The environmental awareness campaign can be made by a variety of methods, such as talks, discussions, and documentary film shows. It can be include interactive events to attract the public, such as mangrove planting contests and environmental quiz competitions. The message can be consolidated through campaign materials like posters, leaflets, and billboards with involving local cultures and customs.

Stone et al. (2008) analyzed the reason why fishermen, fisherwomen and rice farmers want to contribute to mangrove restoration in India. For fishermen, their main reason to take a part in restoration is they believe that mangrove contributes to fish nursery. An economic reason influences fisherwomen’s decision to participate in the restoration as they consider mangrove as an alternative source of income for the whole community. Surprisingly, although Indian farmers are at a higher annual median level than the other groups, only a minority would be willing to contribute to the restoration. This minority is influenced by the perception that mangroves may help control erosion and crop pests.

Furthermore, there was poor coordination among stakeholders in Aceh restoration (Wibisono and Suryadiputra, 2006). Communication and information sharing must be improved. In order to activate this coordination, BRR should take the lead as both initiator and facilitator, by holding routine meetings that involve all the stakeholders and subsequently distribute the meetings results to the various parties in Aceh and Nias. For this purpose, BRR could be assisted by other related institutions such as Department of Forestry and Local Government.

Based on a case study in Philippines, a co-management project in mangrove rehabilitation tends to be more successful. In management of the project, both local community and local government have strong commitment to share responsibilities (Katon et al., 1998).

7.5. Capacity building through provision of technical manuals and training

Almost all field implementers in Aceh had neither the necessary experience nor skills required to undertake coastal rehabilitation activities (Wibisono and Suryadiputra, 2006). As a consequence, rehabilitation programs tend to fail. With simple and easy to understand manuals, there is a hope that the implementers will understand the rehabilitation procedures, from the beginning to the end. Other materials such as posters and leaflets can also help to improve the community’s capacity. However, for some field operators, particularly those with little or no formal education, the manual is not enough since they may be unable to understand it because of its language. For this problem, the manual, which usually in Bahasa or English, can be translate to Aceh language and be re-written especially with the technical terms.

Training activities are also important in the capacity building. This can be done with assisting the community in rehabilitation activities and doing informal meetings regularly in each sub-districts of Aceh.

7.6. The need for sustained tending, monitoring and evaluation

One of the keys to achieve successful rehabilitation is the seedlings tending after they have been planted (Wibisono and Suryadiputra, 2006). The main tasks involved in tending are include: replacement planting, pest and disease control, and weeding. If repeated replacement planting still results in failure, further enrichment should be discontinued. This is likely to occur when the substrate is unsuitable, for example as a result of tsunami deposits. Besides tending, both monitoring and evaluation need to be regularly done.

7.7. The integration of restoration project with associated aquaculture ecosystem

The mangrove restoration efforts in Aceh seem to only focus in the plantations. Although the planting is a good start for rehabilitation, it may need long period of time to do restoration. Rehabilitation is different with restoration because it only notices ecosystem processes, productivity, and services reparation. Meanwhile, the goal of restoration is to return the ecosystem to its historic trajectory and re-establish the pre-existing biotic.

To be successful, the restoration should be integrated with associated aquaculture ecosystem (Ellison, 2000). For instance, there is an operation of ‘sustainable’ mangrove forestry in Matang, Malaysia which is in its third 30 year rotation, has produced 50 % less than before. This suggests that mangrove alone may not be sustainable. Furthermore, mangrove restoration should conserve the natural landscape, sustain the essential values of environment and ecology, provide for coastal population livelihood, and ensure the sustainable production of natural resources such as timber, charcoal, fish and shrimp (Ellison, 2000; Yap, 2000).

BRR as a leader in Aceh could establish a restoration team, whose members can be both internationally or locally people. The team can determine specific restoration goals in periodic of time and implement that in the field.

Conclusion

Although many institutions / organizations have done various projects to restore mangrove and coastal vegetation in Aceh after the 2004 tsunami, its level of success cannot be known yet because of the lack of data and information. According to Wibisono and Suryadiputra (2006), the survival rate of mangrove species is 40%-60% and other coastal species is 20%-50%. This data shows promising efforts of the restoration. To improve mangrove / coastal ecosystem restoration in Aceh, there are 7 recommendations, which are : (1) selection of appropriate species and planting sites, (2) biological indicators for selecting planting site, (3) development of Decision Supporting System for rehabilitation site selection, (4) improvement of active community participation, raising public awareness, and coordination among stakeholders, (5) capacity building through provision of technical manuals and training, (6) the need for sustained tending, monitoring and evaluation, and (7) the integration of restoration project with associated aquaculture ecosystem.

 

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