Management Strategies of Mangrove Degradation in Coastal Areas of Brebes Regency, Central Java, Indonesia

Issue on mangrove degradation and its impact viewed from ecological and anthropological aspects is constantly actual as it will reduce its vital function as a coastal protection from the danger of tsunami and abrasion, nutrient recycling, fisheries productivity biodiversity, dampening the rate of sea water intrusion and other coastal ecosystem crutches. This study aims to: determine the level of mangrove degradation; find out a model of mangrove area reduction dynamics due to the influence of ecological and anthropogenical factors including a model of perceptional correlation, to know community’s perceptions and participation on mangrove degradation; then to further discover more effective strategies in dealing with coastal mangrove degradation in Brebes Regency coastal areas. In the research areas, three species of mangrove vegetation were discovered in proper number; they were Rhizophora mucronata, Rhizophora apiculata and Avicennia marina. Overall, Rhizophora mucronata had the highest density of 35.731 ind./ha. in Kaliwlingi Village, Sub District of Brebes. Mangrove areas in Brebes Regency generally decreased with the reduction rate of 68,46 ha./year. Ecological and anthropogenical factors had the cohesion of the dynamics of a vast reduction in mangrove Brebes coastal areas. The value of natural growth factor (99,60%), reforestation (97,40%), death (99,60%), logging (99,60%), and abrasion (99,60%). Most of the indicators of independent factors, perception and public participation factors showed a significant effect (valid) against the dependent factor (mangrove degradation) at 95% and 90% level of convidence, but the influence of ecological factors were more dominant than anthropogenical factor. The level of public perception had no effect on the level of participation. The results showed that degradation of mangrove forests in Brebes Regency coastal areas were still allowed to be maintained and could be developed. The order of strategies to manage mangrove degradation in Brebes Regency coastal areas were: (1) Improving the protection of the mangrove areas from ocean waves/abrasion through anchoring/ more effective breakwater; (2) Increasing the empowerment of potential mangrove areas through productive activities that increase the added value for improving the welfare of local communities while preserving the mangrove; (3) Making the implementation of regulations and optimizing the role of relevant agencies, civil society organizations, and the participation of local communities in conserving mangrove areas and developing it; (4) Strengthening the institutional system of government and public institutions in the management of mangrove areas for short, medium and long term; and (5) Improving outreach activities/community related to the importance of mangroves for coastal resource conservation.


Introduction
Ecologically, mangroves ecosystem acts as a coastal protector of tsunami hazard and abrasion [1], nutrient recycling, fisheries productivity biodiversity, dampening the rate of sea water intrusion and other coastal ecosystems cantilever [2]. According to the Department of Marine and Fisheries Central Java Province [3], the Brebes Regency has 223.07 ha. mangrove areas, the widest in the region of western coast of Central Java with mangrove vegetation density categories sapling (seedling) 18.400 ind./ha., highest in Central Java Province. On the other side, mangroves in Brebes Regency have been degraded by abrasion and destruction by parties who are not responsible [4]. The degradation of mangrove leads to abrasion and otherwise decreases the quantity and quality of coastal resources including mangroves itself [5,6]. The linkage between ecological and anthropoginical factors in mangrove degradation and abrasion can not be ignored [7]. Improvement efforts for the ecosystem have been done with no provided significant results. In this regard, this study was determined: to analysis the level of mangrove degradation; to find out a correlation of mangrove area reduction due to the influence of ecological and anthropogenical factors; correlation of community perceptions and participation in mangrove degradation; then to discover more effective strategies in dealing with mangrove degradation in Brebes Regency coastal areas.

Data collection
Data of mangrove areas and conditions from Landsat TM satellite image dated May 31, 2013 by the National Aeronautics and Space Agency was processed with GIS technology (Geographic Information System) and then field check was performed. Landsat image imposed data format conversion, image choise, classification, analysis of mangrove vegetation index with Normalized Difference Vegetation Index (NDVI). Data Collection of mangrove vegetation was conducted using transects along 100 m and width of 20 m. In a transect of station of observations a 10 m × 10 m graded plots are made for trees category, 5 m × 5 m for saplings, and 1 m × 1 m for the seedlings, and then all of types and quantities of mangrove vegetation in the plot area are recorded [8].

Data analysis
Data calculating is done by using Microsoft Excel. It consists of calculating the density of mangrove species, type frequency, closing of type relative and importance value index of mangrove [9]. Analysis on dynamic systems of ecological factor is done with Power Sim 2.0 software as stated by [10]. To determine the inter-relationship between the public perception and participation towards the mangroves degradation is done with Structural Equation Modeling (SEM) using LISREL 8.80 program as recommended by [11]. Determination of the more effective policy in handling of mangrove degradation is done through two stages of analysis: SWOT (Strenghts, Weakness, Opportunity, Threat) and AHP (Analytical Hierarchy Process) using Expert Choise V.9 program as recommended from [12,13].

Mangrove ecological conditions
Mangrove area changes and mangrove vegetation conditions: Brebes Regency coastal areas are along 65.480 km. Mangrove areas changes in Brebes Regency coastal areas from 1983 to 2013 as presented in Table 1.
Decline in mangrove area is due to changes in the coastline as a result of abrasion, accretion and mangrove community structure [14,15]. It can be seen from type of density, frequency, closure and the importance value index of each mangrove vegetation type [16] as presented in Table 2.
Species density and mangrove forest area: The highest density for this species of Rhizophora mucronata was found at station 5 (35.731 ind./ha.) and the lowest at station 1 (10.162 ind./ha.). The highest density for Rhizophora apiculata, was found at station 6 (420 ind./ha.), and relative was not found at stations 3 and 4. The highest density of Avicennia marina was at station 5 (500 ind./ha.) and was not found at station 4. Relatively high densities was at Station 5 (Kaliwlingi, Sub District of Brebes) as a result of mangrove reforestation activity at the site, especially species of R. mucronata mangrove vegetation which had resulted in the category of trees and saplings beside the still form of a nursery. The greater of density values shows a good mangroves condition, the lower the number shows the threat of mangrove degradated.

Analysis of normalized difference vegetation index (NDVI):
Mangrove density, according to satellite imagery, can be seen from the results of the analysis using the Normalized Difference Vegetation Index (NDVI), which can separate the vegetation objects with nonvegetation. To distinguish between mangrove vegetation and other vegetation is to look at the vegetation distance to the beach. In this study the distance was as far as 200    analysis using NDVI in Brebes Regency coastal areas, it is obtained 4 groups of mangrove vegetation density. The greatest mangrove area is rarely density, that is 80.34 ha. and the smallest is mangrove vegetation densities in tightly, that is 29.16 ha. Along Brebes Regency coastal area, the mangrove area with very density categories was not found as presented in Table 3.
In general, the density of mangrove was proportional to NDVI values as presented in Table 4. Mangrove area in the Sub District of Brebes beach was the widest for all density categories.

Frequency of mangrove vegetation types (Fi):
Frequency value indicates chance discovery of a particular species on the plot in the observation station [9]. R. mucronata has Fi value of 1.00, the highest frequency of observation is at stations 3, 5 and 6 respectively in Bulakamba sub district and Brebes sub district (Kaliwlingi and Randusanga Wetan villages), which means that species is found in all plots. R. apiculata at stations 3 and 4 in Bulakamba and Wanasari sub districts and A. marina at stations 1 and 4 in Losari and Wanasari sub districts have Fi of 0 (it's not found in all plots observation stations).
At station 1, 2 and 4, respectively in Losari, Tanjung and Wanasari sub districts, R. mucronata has Fi value of 0.6667 which means it is found in two of three plots observation stations. R. apiculata at station l, 2, 5 and 6 respectively in Sub District of Losari, Tanjung, and Brebes (Kaliwlingi and Randusanga Wetan villages). and A. marina at stations 2, 3, 5 and 6 respectively in Sub District of Tanjung, Bulakamba, Brebes (Kaliwlingi and Randusanga Wetan villages) have Fi value of 0.3333, which means it is only found on one plot of three plots in the observation station. In almost all stations, A. marina has a high role, except at station 1 in Losari Sub District which the IVI has its medium categorized . Of all the existing stations, R. mucronata at station 4 in Wanasari Sub District has the highest IVI with a value of 300. The lowest value of R. apiculata are at stations 3 and 4 in Bulakamba and Wanasarisub districts, and A. marina at station 4 in the Wanasari Sub District with a IVI value of 0.

Dynamic system analysis of mangrove areas changes in brebes regency:
The dynamics of mangrove areas changing in Brebes Regency coastal regions are presented in Table 5.
From the data obtained, structured dynamic model of ecological processes and anthropogenic affects mangrove vegetation in Brebes Regency coastal areas as presented in Figure 2.
The change in the mangrove area is affected by the addition of mangrove due to naturally growth factors and reforestation, besides; reduction is due to coastal abrasion and logging of mangrove forests [17][18][19]. From the simulation it is known the rate of mangrove degradation in Brebes Regency following equality Y = 2327 + 0.039 X1 + 0.087X2 -0,021 X3 -0,071 X4 -0.118 X5, where Y ( mangrove areas in Brebes Regency); 2327 (extent of mangroves in Brebes coastal area at the beginning of the calculation, 1983); X1 (addition of mangrove vegetation naturally growth factors); X2 (addition of mangrove vegetation reforestation factors); X3 (mangrove vegetation reduction because of death); X4 (reduction of mangrove vegetation due to logging/burning); and X5 (reduction of mangrove vegetation due to abrasion). Mangrove reforestation effort that has been done can increase the number of mangrove vegetation with an average of 17.82 ha./year, but it has decreased at a rate of 68.46 ha./year, where abrasion, logging and other natural causes of death each providing contribution 56%, 34% and 10%.

Perceptions and public participation: Perception and participation
value of coastal communities about the condition and management of mangroves in Brebes coastal areas are presented in Table 6.
Public perception of mangrove importance is in the range of moderate to very good with an average value of 4.19 (good). The perception was not followed by commensurate participation of 3.76 (medium) as presented in Figure 3. The average of mangrove degradation is in level of 3.50 (moderate).

Analysis of SEM (Structural Equation Modeling):
Correlation model of perception, participation and mangrove degradation in Brebes Regency using SEM (Structural Equation Modeling) Lisrel 8.80 follow [20] is presented in Figure 4.
The results of processing by using SEM program Lisrel 8.80 [20] produces an equation that shows the relationship between variables in the model is modified, as follows: LISREL Estimates (Maximum Likelihood), Structural Equations : These equations can be described as follows: 1. Estimation of the standard error (second row numbers in each equation) is worth less than the coefficient of the equation so that it can be stated that the estimated parameters are relatively precise appear.
2. Most of the independent factors show a significant effect (valid) toward the dependent factor influenced at 90-95% confidence level. It is shown by the indicator validity (t value, the numbers on the 3rd line in each equation which is the ratio between the value of the regression coefficient estimates the error standard) is more than the    (2012), and the research results were processed (2013).  (while the rest is explained by the value of the size of the error) generally shows a relatively small number so it can be stated that the effect of logging/burning mangroves contributes relatively little impact on the dynamics of a vast reduction in Brebes Regency mangrove areas. The more significant factors that play a role in the reduction of Brebes Regency mangrove area are indicated by the relatively large error value and in this case alleged an ecological factor, that is abrasion.

Rehabilitation of mangrove forests:
Mangrove rehabilitation activities in Brebes coastal areas have been being done since 2004. Until December 2004, mangrove vegetation had been done along Brebes Regency coastal areas covering 500 ha. The land that had been replanted consists of an area of 325 ha. and a stretch of dike embankment measuring 175 ha. in 13 villages in five sub districts in Brebes Regency coastal area [21]. R. mucronata was planted at a spacing of l m x l m. One hectare of land was planted with 2000 ± R. mucronata seedling stems. According to [22,23], associated with physical function as wave absorbers that has pounded the coast and biological function as a habitat for marine life, the rehabilitation of mangrove areas directly facing the sea as green belt becomes very important. The area of mangrove reforestation proposal were three regions: in the mouth of Cisanggarung river in Losari Sub District, estuary of Kluwut river in Bulakamba Sub District, and eastern of Pemali river estuary in Brebes Sub District. Mangrove rehabilitation to restore ecological and economical functions needs to consider supporting and inhibiting factors, including the election of mangrove vegetation species according to the type of soil beaches [24]. Based on the type of substrate and the condition of the beach (abrasion and accretion), the mangrove vegetation that can be planted are species of Rhizophora spp.

Perception
The Source: Results of the study (2013) Specification: Value 1: It's not very serious; degradated to 0%, the rapid growth of mangrove (score 1); Value 2: not serious; level of degradated ˂ 10%, mangroves continue to grow normally, there is the addition of mangroves (score 2); Value 3: slightly degradated; the level of mangrove degradation 10 to ˂ 25%, there is an addition/mangrove growth (score 3); Value 4: serious; level of mangrove degradation 25 to ˂ 75%, relative to no addition/ mangrove growth (score of 4); Value 5: very serious; very degradated, ≥75%, no additional and mangrove growth (score 5) Table 6: Perception and participation value of coastal communities about the condition and management of mangrove in Brebes Regency. A. Perception, B. Participation C. The rate of mangrove degradation. and Avicennia spp. for mangrove rehabilitation activities in Sub District of Losari until Wanasari, meanwhile around the estuary of Pemali River Rhizophora spp. can be planted. According to Bengen [9], mangrove species planted for retaining abrasion is Rhizophora spp. and for greening is Avicennia spp. Planting Rhizophora spp. in Brebes Regency coastal areas can be done by tying profagul (mangrove seeds) to 'ijiran' . Ijiran is a place profagul (mangrove seeds) attached, in the form of four split bamboo with a diameter of 2.5 cm, a length of 1.5 m and a weight of 0.25 kg which is plugged into the subgrade coastal waters as deep as 50-75 cm as shown in Figure 5. In some observation stations 'ijiran' are seen collapsed by ocean waves. This is likely due to the lack of proper site selection and embedding depth of ijiran that is less than optimal.
To obtain a balance between the power of mangrove vegetation planted and power surge that has pounded the coast, the amount of potential energy of mangrove vegetation planted must be equal to the power per meter wave front [25].
The highest value in the third observation station is 1.07 m so ijiran should be plugged into the subgrade coastal waters at least as deep as 1.07 m against buckling by the waves of the sea. To streamline the reforestation, it requires the protective building of new mangrove vegetation planted on the ocean wave action. The making of the building should consider the causes of abrasion particularly the direction and strength of currents/waves which fit the pattern of sediments cell formation [26,27]. The building of a breakwater made of bamboo materials in Kaliwlingi beach enable to survive long enough are presented in Figure 6.  coastal, Sub District of Losari has fallen for it was not much stronger to face the wave brunt. This is presumably because the embedding is lacking in, while it is directly facing the Java Sea. Besides breakwater built in the coastal waters tends to be mounted parallel to the coast facing perpendicular wave energy so that the brunt of huge waves breaks down the barrier waves. Similarly, the breakwater of stones piles on the beach of Randusanga-Kaliwlingi Sub District of Brebes. It can not hold the brunt of a wave as shown in Figure 7.

Strategies analysis of management to mangrove degradation in brebes regency: 1. SWOT analysis
The process and result of handling mangrove degradation have been done in Brebes Regency coastal areas are grouped into SWOT matrix for th eanalysis of strengths, weakness, opportunities and threats as presented in Table 7.  Table 8 [28].
Based on the SWOT analysis matrix that has been obtained, the analysis performed to determine the policy strategy that should be done in the framework of the mangrove management areas in Brebes Regency is obtained the ranking strategies of each segment as follows :

Strengths (S) Weakness (W)
1. There is already a mangrove area management regulations from related parties (local government) 2. Brebes Regency has several agencies dealing with the management of mangrove 3. There is a potential coastal communities in mangrove conservation effort 1. Coordination between mangrove agencies is not optimal 2. Local government attention in the mangrove preservation is uneven across Brebes Regency coastal areas, especially in West Brebes 3. Mitigation techniques of coatal abrasion in Brebes Regency are inadequate and not integrated across regency/provinces other Opportunitie(O) SO Strategy WO Strategy 1. By making the mangrove ecosystem as part of the climate change / environment nationally / globally 2. Availability of mangrove management funds in international, national and regional levels. 3. The development of science and technology of coatal abrasion management /mangrove management Optimizing the community empowerment in mangrove management along the coastal of Brebes Regency by won funding available to regional, national and international (2,05) Maximizing of abrasion prevention/reduction in a comprehensive manner to stabilize the presence of mangroves by utilizing related technological developments (2,25)

Threats (T) ST Strategy WT Strategy
1. Conversion of mangrove land as residential and industrial areas 2. Utilization of mangrove resources for household use, pharmaceutical and other industries.

Management of buffer zones of mangrove ecosystems both upstream and downstream regions is not optimal
Minimizing land conversion, logging and destruction of mangroves with effective enforcement of mangrove protection (2. 00) Optimizing the upstream-downstream area management of mangrove buffer areas by improving coordination among mangrove agencies. (2, 20) to make effective enforcement of mangrove protection.

Analysis hierarchy process (AHP)
AHP data analysis based on interviews/questionnaire aiming to determine the priority of Brebes mangrove management is done by using Expert Choise V.9 software. AHP process is done through structural hierarchy of a complex problem that is broken down into parts that are smaller according to the characteristics or specific  amount. Interview/questionnaire is the primary data collection techniques performed to determine what strategy should be carried out by the Brebes Regency Government in defining alternative of mangrove management. Prioritization decision elements is done by making comparisons using a matrix table and analysis of issues raised in the Brebes Regency coastal areas, where the priority terms of problem will be dominating and dominated. Alternative of mangrove management strategies in Brebes coastal areas taken from SWOT analysis results are presented in Figure 8.
The result of a weighted sum of criteria in a hierarchical structure created with Expert Choice V.9 Software. To know the final result of each alternative strategy, calculation is done by counting weight overall or aggregate weights of alternatives toward the existing criteria, from strategy of A, B, C, D and E as shown in Table 9.
From the calculation above, the order of strategic priority to be considered in the mangrove management in Brebes regency coastal areas are: A. Maintain the existing mangrove vegetation and improve the effectiveness of reforestation of mangrove vegetation.
1. Providing protection for newly planted mangrove seeds in areas prone to abrasion by placing break water/damper waves, APO or concrete buis/polybag in the section dealing with the arrival of sea waves. Preparing the coastal structures (groins, seawall) of massive materials such as large rocks, cast materials focusing on the strength, direction, character, currents of waves and cell sediment in Brebes Regency coastal areas [28,29].
2. Doing reforestation of mangrove vegetation by regarding the balancing technique between the energy of the ocean waves with depth of ijiran embedding as a bound mangrove seeds/profagul). In general, if ijiran is in the form of split bamboo 2-4 and weighs about 250 g, the embedding mangroves ijiran should be done to a depth of more than 1.07 m.
3. Selection of mangrove vegetation types according to the type of soil texture. Based on the type of substrate and the condition of the beach (accretion or erosion), then in accordance with the opinion [9,30], mangrove species that can be planted for mangrove rehabilitation activities are as follows: a. The beaches experiencing abrasion and has a muddy sand substrate as in stations 1, 2, 3 and 4 in Sub District of Losari until Wanasari was planted with Rhizophora spp. and Avicennia spp. B. Increasing the empowerment of mangrove potential areas through productive activities that increases the added value for improving the welfare of local communities while conserving the mangrove/coastal resources.
1. Marine aquaculture: Planning and site selection of marine culture should consider the limiting factors, which include site protection and turbidity waters [31]. Based on the site protection factor, Brebes coastal areas are categorized into protected, less protected and unprotected areas. Clear waters are more than 2.5 km from the shoreline, this is marked with the number of step chart in this area, especially in the northern Gulf of Bangsri. Marine culture types that are allowed to be cultivated: (1) sea cucumbers, (2) [32]. Mangrove supervisor group of the community in the Eastern Brebes region, namely Wana Segara group is relatively existing. The group can be used as a reference for the establishment and empowerment of mangrove supervisor groups in the Western and Central Brebes region [33].
3. Providing incentives for people who preserve the mangroves, as well as crab seekers and beaches fishermen at locations near the mangrove forest. The incentives are expected to be emotional attachment to preserve the mangroves, especially the newly planted mangrove vegetation and prone to collapse. It is intended to foster self-awareness of coastal communities in mangrove preserving participation [34,35]. D. Strengthening institutional systems, both government and public institutions in the management of mangrove forests for short, medium and long term.
1. Synchronizing the area of reforestation and mangrove monitoring responsibilities among agencies. This is to overcome the ever arising problems, namely the overlapping of reforestation location and its monitoring at locations relatively easy to reach like the coastal areas of Eastern Brebes. On the other hand, the less affordable areas can not be handled optimally.
2. Matching the perception on mangrove preservation in the conflict of interest according to Gumilar [36], such as mangrove logging in Krakahan Village Sub District of Tanjung for widening channel of water supply of salt manufacture. Those problems can actually be avoided although it needs an additional budget for land acquisition of widening of drains.
E. Increasing the counseling activities/community empowerment, including the youth in line with the importance of mangroves for coastal resource conservation.
1. Involving young people (kindergarten studens until college students) in activities such as mangrove love through: inserting mangrove ecosystems as part of a lesson in school, beach tent, participation in mangrove reforestation, competition of mangrove utilization as food products besides keeping maintaining its sustainability.
2. Increasing the intensity of counseling on the importance of coastal/mangrove resources conservation through radio, TV and other information media, especially on special occasions endear the young generation.

Conclusions and Recommendations
1. The density and degradation of mangroves in Brebes coastal area is in very rare range (badly degradation) to moderate (medium degradation) except in the east coast of Brebes region in Kaliwlingi Village, Sub District of Brebes which has a category of tightly density level (good) because it is an area of mangrove reforestation. Mangrove areas in Brebes Regency coastal areas are reduced with the rate of reduction of 68.46 ha./year.
2. Ecological and anthropogenic factors jointly affect the mangrove degradation in Brebes Regency coastal areas, but the influence of ecological factors (abrasion) tends to be more dominant 3. The condition of mangrove forests in Brebes Regency coastal areas is relatively still possible to be maintained and developed by the more effective strategy.

Recommendation
In dealing with degradation of mangroves in Brebes coastal areas, the orderly strategic priorities should be considered as follows: A. Improving the mangrove area protection from sea waves/ abrasion and developing it through the retaining/optimal breakwater. B. Empowering the mangrove areas potential through productive activities that increase the added value for improving the welfare of local communities and keeping conserving the mangrove/coastal resources.
C. Making the implementation of regulations and optimalizing the role of relevant agencies, civil society organizations, and the participation of local communities in conserving the mangrove areas and coastal resources.
D. Strengthening the institutional systems, both government and public institutions in the management of mangrove forests for short, medium and long term.
E. Increasing the counseling activities/community empowerment, including the youth in line with the importance of mangroves for coastal resource conservation.