Segara Anakan Research Articles

STAKEHOLDERS ANALYSIS OF MANGROVE ECOSYSTEM MANAGEMENT IN SEGARA ANAKAN LAGOON, CILACAP

The mangrove ecosystems are one type of coastal ecosystem found along coastlines and river estuaries that are influenced by tides and inundation. Segara Anakan Lagoon, Cilacap as one type of coastal ecosystem has a protection function, coastal area buffer, and cultivation area function that must be supported from the aspects of policy and institutions, communication, and coordination. This study aims to identify the role of stakeholders and the relationship between stakeholders in mangrove ecosystem management in Segara Anakan Lagoon, Cilacap. The research method used was a survey and interview method analyzed with MACTOR software. The results showed that there were 18 stakeholders who involved in mangrove ecosystem management in Segara Anakan Lagoon, Cilacap. The stakeholders are classified into main stakeholders, key stakeholders, and supporting stakeholders using the objective of mangrove management as key activities such as silvofishery, mangrove conservation, fishing activity, industry activity, etc. The level of convergence between stakeholders was 96.1% and the level of divergence was 3.9%. These results indicate a relatively low potential for conflict between stakeholders. The research can be used as a model relation between stakeholders to support the management activity of Segara Anakan Lagoon.

PHYTOPLANKTON COMMUNITY STRUCTURE IN THE EAST PLAWANGAN OF SEGARA ANAKAN, CILACAP

The East Plawangan waters of Laguna Segara Anakan (LSA), Cilacap are unique waters that are characterized by high biodiversity and are a meeting place for several rivers. It is thought that anthropogenic activities around waters will cause changes in ecological conditions. The organisms that first respond to these changes are phytoplankton. The aim of this research is to determine the structure of the phytoplankton community which includes abundance, diversity index, evenness index and dominance index, as well as to determine physical-chemical factors and the relationship between phytoplankton abundance and physical-chemical factors. The method used is a survey method with Purposive Random Sampling at 5 stations. The f test and Lackey Drop Microtransect Counting method were used to determine the abundance of phytoplankton. Principal Component Analysis (PCA) was used to determine the relationship between phytoplankton abundance and physical-chemical factors. The results showed that the abundance of phytoplankton was in the low and medium categories with values of 840 ± 435 to 3814 ± 939 ind/L; The diversity index ranged from 2.42 - 2.99 (medium); The phytoplankton evenness index ranges between 0.74 - 0.89 (high) and the phytoplankton dominance index ranges from 0.06 - 0.14 (low). Physical-chemical factors in East Plawangan are still at the threshold that can be tolerated by phytoplankton. PCA analysis showed a relationship between phytoplankton abundance and physical-chemical factors as indicated by two main factors (F1 and F2) which produced a variance value of 87.49% with the most influencing factor being orthophosphate.

Spatial Distribution Of Heavy Metals Cd And Cu In Water, Sediment And Fish (Mugil Sp) In Pelawangan East Segara Anakan Cilacap

Heavy metals are widely known pollutants with bioaccumulative nature, so they can be transferred and accumulated in biota, such as mullet fish (Planiliza subviridis). The heavy metals Cd and Cu have different anthropogenic and natural sources. Heavy metals have the potential to absorb existing biota such mullet fish. Fish absorb metals from the water in the body through gills, skin surface and food. This study aims to identify Cd and Cu metals in distribute water, sediment and mullet fish in the Plawangan Timur, Segara Anakan lagoon, Cilacap, Central Java, and the relationship between aquatic media and sediment and mullet fish. The study used a research method with a targeted random sampling method at five stations with four replications. The survey was conducted from April to September 2020. Descriptive data analysis, F-test, regression and correlation. The results showed in water, sediment and mullet fish the heavy metal content of Cd and Cu varied between stations. The correlation between the Cd and Cu metals in water, sediment and mullet fish showed a positive correlation. The content of heavy metal Cd in mullet fish media in Plawangan Timur Segara Anakan Cilacap has exceeded the specified quality standard, while for heavy metal Cu in mullet fish is still below the specified quality standard.

BIODIVERSITAS GASTROPODA DI HUTAN MANGROVE SEGARA ANAKAN CILACAP

Segara Anakan is a lagoon surrounded by swamp forest with a mud substrate. Several biota live in it, one of which is Gastropods. This biota has slow movements and is relatively sedentary. The aim of research on gastropod biodiversity is to describe the diversity and dominance of their species. The research was conducted in July-September 2021. The research method used was a survey with a purposive random sampling technique at three stations taking into account differences in vegetation community structure. Station 1 (St 1) is in the eastern part of Segara Anakan with vegetation that dominates Aegiceras corniculatum; Station 2 (St 2) is in the middle of Segara Anakan with vegetation that dominates Nypa fruticans; Station 3 (St 3) is in the western part of Segara Anakan with vegetation dominating Sonneratia alba. Each station is determined by nine different sampling points once every month. The results showed that the Potamididae and Neritidae families were most commonly found at all stations during the study. The highest abundance is found in St 3, namely 1433 ind/m2, the lowest in St 1, namely 545 ind/m2. The diversity index in the medium category is at St 1 (1.05) and St 3 (1.59), while the low category is at St 2 (0.85). The dominance index in the medium category is at St 2 (0.55), and in the low category at St 1 (0.47) and St 3 (0.28). Factors that influence differences in abundance, diversity and dominance are adaptation, food and environmental conditions in which they live.

NEED FOR SIGNS ON THE SEGARA ANAKAN RIVER, CILACAP REGENCY

The Segara Anakan River is a shipping channel with a channel length of 17.8 miles that serves the Seleko – Kampung Laut Route in Cilacap Regency. The condition of shipping flows in Segara Anakan is irregular due to the lack of river signs as a means of regulating traffic to create safe, secure and smooth river transportation. This research aims to determine the number of river signs needed and evaluate existing river signs. This research was carried out by reviewing field conditions and then conducting qualitative descriptive analysis in accordance with Perditjenhubdat Number: KP. 4755 / AP005 / DRJD / 2020 concerning Technical Guidelines for River and Lake Signs. Conditions in the field are that the number of signs installed is 5 compared to the supposed number of 9. The research conclusion is that the number of river signs needed in the Segara Anakan channel is 25 signs with details of 6 prohibitive signs, 3 mandatory signs, 2 warning signs. The required river signs must meet technical specifications in accordance with applicable regulations both in terms of size of sign leaves, sign poles and manufacturing materials.

Enhanced mangrove index: A spectral index for discrimination understorey, nypa, and mangrove trees

Unsupervised classification using vegetation indices has been extensively employed to map mangrove forests using medium-resolution satellite images. However, its capability is restricted to determining the extent of mangroves only. This study introduces a new spectral index called the enhanced mangrove index (EMI) for accurately mapping different components of mangrove vegetation, including mangrove trees, nypa, and understorey. An immediate effort is required to monitor the invasion of nypa and understorey in the mangrove forest of Segara Anakan Lagoon, located in Central Java, Indonesia. This issue may also be prevalent in other mangrove areas worldwide. The development of EMI involved: 1). the analysis of the reflectance exhibited by different types of mangrove vegetation, and 2). The performance of EMI was evaluated by comparing it with spectral indices such as automated mangrove map and index (AMMI), as well as supervised classification models like random forest (RF). The accuracy assessment indicates that the overall accuracy and Kappa coefficient achieved values of 0.87 and 0.84, respectively, surpassing other spectral indices and supervised classification models. AMMI and RF exhibited high overall accuracy, with values of 0.82 and 0.73, respectively. Additionally, they demonstrated a Kappa coefficient of 0.77 and 0.66, respectively.

THE SPECIFIC ORDINATION AND CLUSTERING OF MANGROVE ECOSYSTEM IN SEGARA ANAKAN

Mangrove ecosystem has specific ordination and clustering following the adaptation toward the environment properties and species competition. This research aimed to develop a specific ordination to support ecosystem stability. The research was carried out with a multidimensional system using density and environmental properties with similarity and Euclidian distance indexes. The results showed that West Segara Anakan had 6 ordination areas, and East Segara Anakan had 5 ordinations with the range density of 68-3373 trees/ha and 550-2975 trees/ha. Based on environmental properties, WSAL had nitrate, phosphate, pyrite, water and soil pH, and water salinity levels of 10.57-31.44 mg/lt, 8.44-22.89 mg/lt, 1.03-1.57 %, 5.60-7.78, 6.58-7.03, and 24.15-33.85 ppt, respectively. In ESAL, nitrate, phosphate, pyrite, water and soil pH, and water salinity were within the range of 19.72-28.98 mg/lt, 10.83-19.72 mg/lt, 1.28-2.91%, 6.35-7.05, 5.91-6.23, and 18.00-32.33 ppt. Furthermore, specific ordination showed that Avicennia marina, Rhizophora stylosa, Rhizophora apiculata, and Nypa frutican had the highest level of adaptation. I special thanks for research Terapan Unsoed 2023 to support this research.

Mangrove density and delta formation in Segara Anakan Lagoon as an impact of the riverine sedimentation rate

Abstract. Cahyo TN, Hartoko A, Muskananfola MR, Haeruddin, Hilmi E. 2024. Mangrove density and delta formation in Segara Anakan Lagoon as an impact of the riverine sedimentation rate. Biodiversitas 25: 1276-1285. Segara Anakan Lagoon (SAL) is in Southwestern of Central Java Province, Indonesia. The Western Part of SAL (WP-SAL) gets its sediment load from the Citanduy River. This research aimed to determine the temporal pattern of the shoreline, water body area, depth, delta formation, and mangrove density at WP-SAL. Shoreline data were extracted from a base map and the satellite imagery. Overlapping analysis of several shorelines and depth maps showed different results in terms of values or patterns. The western part of SAL had silted up and reached more than 85% in 161 years. The sediment accretion impacted the shoreline (between 177 ha yr-1 in 1999-2003), and the average decrease of the water bodies speed was 61 ha yr-1. The Pelawangan Barat waters (PBW) and the main lagoon had a decreasing depth because of the sediment deposits. The sedimentation also greatly impacts mangrove species distribution, clustering and association, and density and mangrove affinity. Mangrove density growth-based and the delta formation were formed and developed following the tidal pattern during floods and ebbs. It can be used to predict the future morphology of WP-SAL. The WP-SAL will be sediment filled and left the waterways channels, it was reached within 13.6 years from 2018, which would be in 2032.

Community-Based blue economy development in Mangrove Ecosystems (Case study in the Segara Anakan Lagoon, Cilacap Regency)

This study aims to examine the direction of blue economy development in the Segara Anakan Lagoon, Cilacap Regency. This research uses descriptive qualitative method with SWOT analysis. The sampling technique used in this research is purposive sampling technique. Data collection techniques used were field observations, in-depth interviews, documentation, and literature study. This study adopted Miles and Huberman’s data collection which consisted of three activities, namely data reduction, presentation, and drawing conclusions/verification. The results showed that there were 6 villages and/or sub-districts which were the research locations because they were located in the Segara Anakan Lagoon area, namely: Kutawaru Sub-District, Tritih Kulon Sub-District, Klaces Sub-District, Ujung Gagak Sub-District, Ujung Alang Village and Panikel Village. Some of the blue economy activities carried out by the community without destroying the mangrove ecosystem in its development are 8 strength factors, 11 weakness factors, 7 opportunity factors and 9 threat factors.

Morphological and Genetic Diversity of Mangrove Species Ceriops tagal (Perr.) C.B. Rob. Around Java Island

Ceriops tagal (Perr.) C.B. Rob can be found in Baluran National Park, Kepulauan Seribu National Park, Karimunjawa National Park, and Segara Anakan Cilacap in Java and its surrounding areas. These locations have different demographics and environmental conditions. Plant species found in different geographical areas have varied genetic structures and morphological traits as a result of their adaptability to their environment. The goal of this study is to evaluate the morphological and genetic differences between the four populations of C. tagal in Java and its surroundings. Internode length, leaf length, leaf width, petiole length, and leaf area were the morphological characters used. The Internal Transcribed Spacer (ITS) region is used as a molecular marker. The UPGMA dendogram was used to analyze the morphological similarity, and multidimensional unfolding analysis was used to determine which character most determined the grouping. Mega X software was used to analyze genetic variation using the neighbor-joining approach, while Arlequin 3.5 software was used to estimate genetic variation within and among populations. The results of this study showed that the population of Baluran National Park has features or is distinct from the other three populations based on morphological and genetic characters; this could be because of variations in geographic conditions, and that population diversification was aided by a combination of genetic and physical divergence, restricted gene flow, and local adaptation.

Predicting the Distribution of Mangrove Forests through Random Forest Algorithm by Combining Spectral Features and DEM Data

Using satellite data and machine learning-based classification methods for mangrove forest identification has gained popularity due to their effectiveness in producing high accuracy. Therefore, this research developed a random forest classification model using various dataset combinations representing spectral and topographical aspects to identify mangrove forests in Segara Anakan, Cilacap. We used the Sentinel-2 imagery acquired in 2022. Two types of digital elevation model (DEM) data were utilized, namely the National Digital Elevation Model (DEMNAS) and Multi-Error-Removed Improved-Terrain DEM (MERIT DEM). Another critical dataset used is the Normalized Difference Moisture Index (NDMI), derived from the ratio between near-infrared (NIR) and shortwave-infrared (SWIR) bands. The classification method used is the random forest algorithm on six different dataset combinations, including IMAGE, IMAGE+NDMI, IMAGE+DEMNAS, IMAGE+MERIT DEM, IMAGE+NDMI+DEMNAS, and IMAGE+NDMI+ MERIT DEM. The results showed that the combination of Image+DEMNAS and Image+NDMI+DEMNAS datasets was able to identify the mangrove forests more optimally. Incorporating DEM data alongside IMAGE and NDMI datasets resulted in a remarkable level of accuracy in mangrove forest mapping, exceeding 90%. DEM data has a very important role in increasing the classification accuracy of mangrove forests using the random forest algorithm.

Water Quality and Pollution Level in Plawangan Barat, Segara Anakan, Cilacap Based on Pollution Index Approach

Segara Anakan is a lagoon located in Cilacap, Central Java. It is characterized as a fragile ecosystem that is very susceptible to the impacts of alterations and land development. This region is susceptible to habitat degradation caused by human activity, resulting in alterations in water quality and pollution. The objective of this study was to provide a comprehensive description of water quality by analysing its physical and chemical properties. Additionally, the study intended to assess the level of water pollution by employing the Nemerow Sumitomo Pollution Index (PI) approach. The water quality sampling was conducted in the western region of Segara Anakan, namely Plawangan Barat. The obtained data were compared to the established standard quality for marine organisms, as outlined in the PP RI No. 22/2021. The classification of the water pollution level was determined according to Minister of Environment Decree No. 115/2003. The findings of this study indicate that the parameters of temperature, salinity, pH, dissolved oxygen (DO), and biological oxygen demand (BOD) in the water remain suitable for marine life throughout all study stations. However, it was observed that the levels of Total Suspended Solid (TSS), phosphate, and nitrate did not match the established safety thresholds. The pollution index indicated that the water quality in West Plawangan shows varying pollution levels, ranging from light to moderate pollution. Based on the findings obtained, it can be concluded that the Segara Anakan lagoon exhibits a diminished level of suitability for the life of marine organisms.Keywords: Water Quality, Index PI, Nemerow Sumitomo, Plawangan Barat, Marine Pollution

Peningkatan Pemahaman Masyarakat dalam Membangun Konservasi Mangrove di Segara Anakan Cilacap

Communities in the Segara Anakan Lagoon area of Cilacap still do not firmly understand the services of mangrove ecosystems and the impacts that will occur due to the loss and destruction of mangrove ecosystems for people's lives, the sustainability of community economic activities, and the existence of habitat organisms in Segara Anakan. For this reason, it is necessary to conduct socialisation activities on the importance of mangrove ecosystems to maintain their ecosystem services through mangrove conservation activities. This activity was attended by fishermen, stakeholders, boat drivers, kerrang collectors, pond farmers, nipah craftsmen, nifah sugar makers, and so on. The socialisation resulted in an increased understanding of the importance of mangroves, mangrove ecosystem services, and the impacts that will occur if mangroves are damaged. For this reason, the community is also willing to conserve and rehabilitate mangrove ecosystems in Segara Anakan.

Comparison of Mangrove Index (MI) and Normalized Difference Vegetation Index (NDVI) for the detection of degraded mangroves in Alas Purwo Banyuwangi and Segara Anakan Cilacap, Indonesia

Deterioration of the environmental quality of mangrove ecosystem must be identified as early as possible for management and threat mitigation. Degraded mangrove areas have to be distinguished from healthy ones. Low value of Mangrove Index (MI) corresponded to the degraded mangrove area where dominated by two species (Derris trifoliata and Acanthus ilicifolius), which are indicators of mangrove degradation at Segara Anakan mangrove area. The Normalized Difference Vegetation Index (NDVI) failed to detect the degaradation due to existing of these species by detecting as high index value. The study was designed to (1) test the performance of MI at Alas Purwo mangrove area which categorized as a non-degraded mangrove forest, (2) compare the spatial pattern of MI images with that of NDVI images, and (3) further investigate the ability of MI to detect areas of degraded mangrove when it occurs in only small areas. We used Landsat-8 OLI imagery because it includes the short-wave infrared (SWIR) bands required to generate MI. Both direct visual comparison and correlation analysis of the resulting maps were conducted to evaluate the ability of these indices to detect degraded and non-degraded areas of mangroves. In general, both indices detected a similar pattern, which is contrary to the results from Segara Anakan images. However, a difference value between MI and NDVI of >0.2 indicated the presence of small areas of vegetation with a spectral reflectance similar to that of species indicating degradation at Segara Anakan. This finding was confirmed by field observation of mangrove species. A difference of >0.2 between MI and NDVI indicates mangrove degradation for small areas. This study provides a new tool to determine the condition of mangrove forest remotely, allowing for rapid and targeted management action to tackle degradation.

Mangrove forest encroachment by Nypa frutican, Derris trifoliata, and Acanthus spp. in Segara Anakan Lagoon

Based on phytosociological methods and land cover change analysis, previous studies in Segara Anakan Lagoon (SAL) indicated the spreading of mangrove species living in the forest margin ecotone into the forest interior, encroaching the other mangrove communities. This current study aims to quantify the spreading pattern of those mangrove species, assess the effect of the spreading of those mangrove species to the other mangrove communities, and identify the location of the spreading pattern relative to the newly emerged islands. The spreading pattern can be demonstrated by analyzing landscape structures quantified by landscape metrics. It was done using multi-temporal mangrove maps, representing the changes in mangrove communities over four periods with a decade interval. The landscape metrics used were the aggregation index, the size of community patches, and the distance between the patches. These metrics were extracted by using landscape metrics, an R package. The changes in the metrics over time were compared namely 1990, 2000, 2010, and 2020. The results showed that the small patches of the forest margin species became more aggregated into a larger patch, while the mangrove forests became more fragmented. This condition occurred most in the west part of SAL where the new islands emerged.

Comparison of Reproductive Aspects of the Tropical Eel Anguilla bicolor (McClelland 1884) in Freshwater and Estuarine Habitats

The tropical anguillid eel, Anguilla bicolor McClelland, experiences significant growth up to the adult size in both freshwater and estuarine ecosystems, encountering salinity gradients that may impact their reproduction. Therefore, this study aimed to investigate the reproductive aspects of A. bicolor collected from Serayu River (freshwater) and Segara Anakan (estuary), Cilacap, Central Java, during July 2020 field surveys. The examined parameters included eye index (EI), fin index (FI), gonadosomatic index (GSI), hepatosomatic index (HSI), and sex ratio of eel specimens in freshwater and estuary. Furthermore, the total length (TL) and body weight (BW) ranged from 260 - 630 mm and 18 - 419 g in freshwater, and 260 - 630 mm and 18 - 447 g in estuary. Significant differences (P<0.01) were observed in the reproductive characteristics between the two habitats (P<0.01), with higher eye index, fin index, gonadosomatic index, and hepatosomatic index in freshwater-caught eels than the values obtained in estuary inhabitants. The mean of these four parameters were 6.99 ± 2.98%, 4.08 ± 0.71%, 1.70 ± 1.13%, and 1.92% ± 1.07 in freshwater, while 3.48 ± 1.60%, 3.45 ± 0.479%, 1.12 ± 0.23%, and 0.28 ± 0.19% were found in estuary. The sex ratio was significantly affected by habitat, with female eels dominating in freshwater (62.5%) compared to estuary (32%). These results suggested that eels in freshwater habitats might exhibit early gonadal maturation compared to those in estuary.

Mangrove Landscaping As An Adaptation Pattern To Reduce The Impact of Climate Change in Segara Anakan Lagoon, Cilacap Regency Indonesia

Mangrove Landscaping As An Adaptation Pattern To Reduce The Impact of Climate Change in Segara Anakan Lagoon, Cilacap Regency Indonesia

TEKNOLOGI PANEL SURYA UNTUK PENGOLAHAN LIMBAH SISA PENYULINGAN MINYAK KAYU PUTIH

Ujungmanik Village, Kawunganten District, Cilacap Regency, which is in the Segara Anakan Cilacap area, has natural resources, especially eucalyptus plants, which have the potential to develop the economy of the village community. The biggest problem faced by LMDH Dadi Makmur as a unit that manages the eucalyptus oil business is that after the production of eucalyptus oil distillation, it will produce residual waste from cajuput oil twigs and leaves with quite a large volume and only be left piled up around the yard where the distillery is, causing area storage of essential oil raw materials is narrow and also takes a long time to become organic fertilizer. The innovation offered through this community service activity is implementing a briquette printing machine from eucalyptus oil refining waste which is energy efficient and based on solar panels. The results of the dedication show that the eucalyptus oil waste processing activity in addition to reducing environmental pollution also produces biomass briquettes that can be utilized by the residents of Ujungmanik Village as a leading economic product of Ujungmanik Village. Keyword: Cajuput oil, briquette, solar panels

Gonad Homogeneity, Maturity, and Gonado-Somatic Index of Wild Indonesian Eel (Anguilla bicolor bicolor McClelland, 1844)

Abstract The current study was conducted to investigate the homogeneity of gonad maturity in Anguilla bicolor bicolor, and whether Gonado-Somatic Index (GSI) is a reliable indicator of this maturity. Eel samples were obtained from fishermen at Segara Anakan, Cilacap, Central Java, Indonesia in December 2015, and May 2017. Fourteen specimens were analyzed based on their gonad histological structure from cranial, medial, and caudal portions and were measured for GSI values. The present study shows that there is a synchronization of oocyte maturity time on the medial, cranial and caudal parts. It might suggest that during the maturation process, Anguilla develop into silver eels and return to the sea to spawn. The highest GSI value is 2.67 in the female eel containing the highest number of mid-vitellogenic oocytes. Based on these results, it can be suggested that GSI are a suitable parameter for measuring the gonadal maturity of female A. bicolor bicolor. Keywords: Gonadal maturity, Homogeneity, Indonesian eel, A. bicolor bicolor, Segara Anakan

Differences in Swim Bladder Histology of <i>Anguilla bicolor bicolor</i> at Various Stages of Sexual Maturity

The current study observed the histological differences of the swim bladder of the tropical eel, Anguilla bicolor bicolor, as an adaptation resulting from hydrostatic change. A total of 15 eels were collected from Pasir Puncu, Keburuhan, Purworejo and Segara Anakan, Cilacap, Indonesia in June 2017, September 2020, and April 2021. The eels were grouped into 4 stages based on the silvering stage and sex, namely: yellow undifferentiated, yellow female, silver male, and silver female. The average length and body weight of yellow undifferentiated eels were 255.07 ± 45.91 mm and 13.66 ± 8.5 g, respectively; for yellow female, the values were 374.35 ± 41.51 mm and 56.5 ± 12.02 g; for silver male, the values were 432.43 ± 15.15 mm and 140.29 ± 13.85 g; and for silver female were 702 ± 0.00 mm and 545 ± 11.31 g. The present study successfully recorded the histological structure of the swim bladder of A. bicolor bicolor in silver male and silver female stages. Silver males and females displayed a greater significant development of the swim bladder than yellow stages in the gas gland, mucosa, and submucosa layers. These results suggest that an increase in the gas gland thickness allows a greater contribution from gas to gas secretion, the mucosa exerts a mechanical effect on the newly formed gas bubbles, and the submucosa thickness reduces gas conductivity from the swim bladder wall.