Presence of Anisakis Larvae on the Demersal Fish Purple-Spotted Bigeye Priacanthus tayenus Richardson, 1846 From the North Coast of Java, Indonesia

Nugroho D, Patria MP, Supriatna J, Andrianto L. 2016. Biological characteristics on three demersal fish landed in Tegal, north coast of Central Java, Indonesia. Biodiversitas 17: 679-686. Java Sea has a potential marine biodiversity that has been harvested since years. Demersal fish resources is one of the targeted species by Danish seine fisheries operated in North coast of Java. To support on developing conservation and management measures, an observation on species composition, length frequencies and maturity stages were carried out during August 2014 to July 2015. Sampling took place in landing place of Tegalsari fishing port central Java. A total 129 fish species identified, among them 91 species were targeted as edible fish. Sampling on three dominant species i.e., Purple-spotted bigeye Priacanthus tayenus (Richardson, 1846), Lattice monocle bream Scolopsis taenioptera (Cuvier, 1830) and goatfish Upeneus sulphureus (Cuvier, 1829) were measured regarding length, weight and their maturity stages. The results shows that length-weight relationship for each species were P. tayenus W = 0.0324 L 2.7321, S. taenioptera W = 0.0366 L2.7262 and U. sulphureus W = 0.038 L2.7312.Monthly average GSI of P. tayenus and S. taenioptera indicated that the highest index occurred during SE monsoon while U. sulphureus on NW monsoon. Maturity stage analysis indicated that estimated of length at first maturity (Lm) were at 12.9 cmFL (U. sulphureus), 16.8 cmFL (S. taenioptera) and 19.4 cmFL (P. tayenus). Size frequency distribution shows that most of the fish were caught at immature cohorts. The diversity or evenness indices of ichtyofauna is also described as descriptors of community structure and be complemented with information on biological characteristics of those dominant species.Keywords: Demersal fish, dominant species, biological characteristics, north coast, Java

Oktaviani D, Faizah R, Nugroho D. 2018. Biological aspects of Longfin Mojarra (Pentaprion longimanus, Cantor 1849) in north coast of Central Java, Indonesia. Biodiversitas 19: 683-689. Longfin Mojarra (Pentaprion longimanus) locally named as rengganis, is a demersal fish species that is commonly caught in Scottish seine fisheries off the north coast of Java. The fisheries are in heavily harvest level since decades. The aim of this study was to observe the biological aspects of this species. Observations were made between August 2014-July 2015 from Tegal fishing port, western part of north coast central Java. General life-history parameters were measured, i.e., monthly length frequency for 1876 fishes, among them 573 specimens were observed for length-weight relationship, including 541 specimens for sex ratio and maturity stages. Fulton index, Gonadosomatic index, sex ratio and estimated length at first mature were analyzed. The result showed fish size ranged between 7.4 to 15.3 cmFL with the average length of 11.2+1.75 cmFL. We found that length-weight relationship tends to be isometric which statistically the body growth coefficient (b) is equal to 3 (tc = 0.53 < tab; p<0.05) . Monthly Fulton indexes ranged between 1.05-2.87 with an average of 1.90 + 0.17. Sex ratio during observation was not significantly different (p<0.05) from the expected ratio of 1: 1. Mature females occurred year-round with the highest percentage observed from January to April 2015. The estimated length at first maturity was 13.04 cm FL. These biological parameters will be used to support the population study of the future demersal fish species to improve conservation and management measures.

The influence of the earth-moon-sun system on tide events has long been known. However, the impact can vary in different coast areas. The short-term (monthly and yearly) impact of maximum tides needs to be watched out for in relation to tidal flooding, especially if it is reinforced by bad weather at sea. In 2021 NASA reported the results of the Sea Level Change Science Team study that in the 2030s tidal floods will become more frequent and threatening the coasts of the United States due to the 18.6-year lunar orbit nodal cycle which amplifies the effects of global warming. Analysis of maximum tides on the north coast of Java (using data from Jakarta and Surabaya) and on the south coast of Java (using data from Cilacap) shows that on both the north and the south coast of Java, there is no indication of the nodal cycle of the 18.6 year due to lunar orbit. However, this study shows that in short-term annual and monthly cycles there is a difference in the pattern of maximum tides on the north coast and the south coast of Java. The declination of the sun when it is most northerly (the end of June) and most southerly (the end of December) affects maximum tides on the north coast of Java, as semi-annual cycle. Meanwhile on the south coast of Java, only the southernmost declination of the sun (in the end of December) has an effect on the maximum tide, as annual cycle. For monthly cycles, maximum tides on the north coast of Java are affected by the maximum declination of the moon and moon’s perigee (in Jakarta) or by the moon phases and perigee (in Surabaya). Meanwhile, on the south coast of Java it is only affected by the moon’s phases and perigee.

Horseshoe crab is an important component of macro-benthos communities in the fine sand or mud substrate in coastal waters, both in the tropical and temperate region. This primitive animal consists of four species in the world, and three species can be found di Asian region, including Indonesia, namely Tachypleus tridentatus, T. gigas, and Carcinoscorpius rotundicauda. Scientific information about species distribution of three Asian horseshoe crab in Indonesia is limited, also about morphometric characters. This study aims to determine the morphometric characters and species distribution of three Asian horseshoe crab in north coast of Java and south coast of Madura Island. This study was conducted on July-August 2016. The total number of three Asian horseshoe crab obtained in this study was 260 individuals, distributed along north coast of Java and south coast of Madura Island, respectively 176 individuals of C. rotundicauda, 35 individuals of T. tridentatus, and 49 individuals of T. gigas. Tachypleus gigas has the largest size and widest class interval among three Asian horseshoe crab species. Morphometric characters is differences among three Asian horseshoe crab species. Carapace width and telson length were not significantly different among sampling locations only in T. tridentatus.

ABSTRACTThe history of land subsidence and coastal flooding along the northern shore of Java is wide and intricate. Pekalongan, situated on the northern coast of central Java, has seen rapid and substantial land subsidence and coastal flooding. Coastal sedimentation, which leads to the formation of alluvial soil layers that are prone to natural compaction, is the primary cause of land subsidence problems on the north coast of Java. It is also worsened by the additional load of structures and infrastructure above it, as well as the excessive groundwater extraction, especially in industrial and highly populated areas. Due to the tides, the low‐lying regions encounter coastal flooding, exacerbating the circumstances for the inhabitants residing along the same coastline. Local communities have made multiple efforts to adjust to the land subsidence and floods along the coast. This article analyses the phenomenon of land subsidence and coastal flooding in Pekalongan, along with the strategies implemented by the local community and government to address this issue. It aims to provide a thorough examination of the challenges associated with land subsidence and coastal flooding along the north coast of Java and to develop effective techniques for managing land subsidence and coastal flooding in different regions.

Land subsidence along the northern coast of Java, Indonesia, represents a critical geohazard due to its substantial socioeconomic impacts, particularly the exacerbation of coastal flooding and structural damage. Quantification of spatial and temporal variability in subsidence rates is imperative for effective mitigation strategies. This study aimed to analyze these patterns using precise geodetic observations. Daily GNSS data collected from five stations of the Ina-CORS network (Tegal, Pekalongan, Semarang, Jepara, and Rembang) were rigorously processed using GAMIT/GLOBK software. The results demonstrate heterogeneous land subsidence rates, with Semarang (−89.08 mm/yr), Pekalongan (−78.84 mm/yr), and Tegal (−20.33 mm/yr) exhibiting the highest subsidence rates. In contrast, Jepara and Rembang CORS stations remained relatively stable, indicating the influence of localized factors on the deformation mechanism.

The concern over floods in the northern coast of Java is more pronounced. The increasing frequency of flood events, material damage and death rates underscore the importance of integrated efforts in controlling floods there. Brebes Regency has good prospects for economic growth and infrastructure. However, because its location on the north coast of Java makes it vulnerable to flooding. Considering this, it is necessary to carry out a comprehensive evaluation of flood hazards and risk assessment in Brebes Regency, as part of efforts to mitigate flood disasters and encourage the development of Brebes Regency as a resilient city. Flood hazard and risk assessment involves the use of spatial analysis techniques, which include the process of examining the level of vulnerability, determining flood hazard zones, and creating a flood risk map. Vulnerability analysis incorporates land use, population density, and economic activities. Flood hazard zoning assessment were carried out using rainfall data, tidal water levels and topography. The findings of the risk assessment indicate that the northern region of Brebes Regency has a high level of risk of flooding. Moreover, these flood risk maps can serve as a valuable tool to inform and guide the development of flood mitigation strategies and infrastructure.

Anchovy is one of the economically important fish in the western part of the northern coast of Central Java. The production of anchovies extends along the coast from Brebes Regency to Batang Regency. Therefore, this study aims to determine the diversity of anchovies on the northern coast of Central Java (Brebes, Tegal, Pemalang, Batang, and Kendal), using a molecular approach. This study was conducted from April to September 2019 in the Laboratory of Tropical Marine Biotechnology, Faculty of Fisheries and Marine Science, Universitas Diponegoro. The descriptive exploratory method was applied in this study with a random sampling technique, while the cytochrome oxidase I (COI) gene was used for molecular identification. An anchovy sample molecularly identified from each region was found by sampling, including BB 3, PML 2, BTG 1, BTG 2, BTG 4, TGL 2, TGL 4, KDL 1, and KDL 4. The base-pair length of 10 anchovy samples from the COI gene amplification result was 600-700 bp. The sequencing and alignment results of the BLAST analysis showed that the ten anchovy samples were included in the type of Encrasicholina heteroloba, Stolephorus commersoni, Stolephorus waitei and Atherinomorus sp., which ranged from 98 to 99% similarity in location. Therefore, it is concluded that there were at least four different species of anchovy on the northern coast of Java. However, further research is suggested to determine the genetic variation of each species for better fisheries management.

This research aims to explain the Pasai Muslim diaspora on the North Coast of Java. This research uses historical research methods which include heuristics (primary sources such as Suma Oriental Tome Pires and secondary sources such as Asian Trade and European Influence in the Archipelago between 1500 and around 1630, Sociological Historical Studies of Indonesian Society Volume 1, Islamic Archeology of the Archipelago, Critical Review of History Banten, Sunan Gunung Jati (between Fiction and fact) Grounding Islam with a structural and cultural approach), source criticism, interpretation, and historiography. The results of this research found that the process of the Pasai Muslim diaspora in the North Coast of Java occurred in the 16th century, resulting in the formation of the Cirebon Sultanate. It also shows that the Pasai Muslim diaspora had spread to parts of West Java brought by Sunan Gunung Djati. After controlling the West Java region, Sunan Gunung Djati then founded the Sultanate of Banten, led by his son, Sultan Hassanudin. Keywords: diaspora, Muslim, Pasai, North Coast of Java

Indonesia has many beaches that attract the attention of tourists, including the north coast of Java. In addition to visual appeal, there are also other potentials such as settlements, agriculture, fisheries, ports, ponds, and other resources. However, there is also a threat to coastal damage caused by, among other things, wave action, tides, abrasion, and tidal flooding. For this reason, in developing coastal areas on the north coast of Java, it is necessary to consider the potential for damage to the coast based on the physical condition of the coast and a system that can classify the vulnerability levels of coastal areas is also needed. The Coastal Vulnerability Index (CVI) can be determined and classified using for example the Gornitz formula, or using data driven model and machine learning based on the coastal parameter data. This study demonstrates how the K-Nearest Neighbor, also known as K-NN algorithm, can be used to classify the level of vulnerability of the coastal areas. This study uses 290 points (locations) along the northern coasts of Java. The parameters that determine the coastal vulnerability are mean sea level (MSL), mean significant wave height (MSWH), mean tidal range (MTR), shoreline changes, landforms and slopes. In this study, the classification of coastal vulnerability levels is classified into 4, namely “low, moderate, high and very high”. The K-NN system uses 80% of the data for training and 20% for testing, with the value of K = 1 to 10. The test results show that the K-NN method is capable of classifying the vulnerability levels of the North Coast of Java. From the test results for values of K = 1 to K = 10, and by randomizing the training data and test data gives an average accuracy rate of 86.21% to 97.13%, with the best K value obtained at K = 2.

Fishing conditions on the North Coast of Java are known to experience overfishing; This then has an impact on low fisheries productivity which then triggers conflicts between fishermen, increases the poverty of fishermen, and threatens the food security of coastal communities whose livelihoods are very dependent on fish resources in the sea. Therefore, this study examines potential conflicts among small-scale fishermen in the use of fish resources and its impact on food security also the resolution of these conflicts. The method used is a qualitative approach supported by quantitative data. Data analysis refers to the structural-functional theory and conflict theory. The study results show that conflicts for livelihood mostly occur among small-scale fishermen. The forms of conflict that small-scale fishermen often perpetrate are vandalism and petty theft, with protests or sanctions that are given only to be silenced because coastal fishermen on North coast of Java still uphold Javanese culture, which prefers to live in peace and harmony. Some of the actions taken to secure food when conflict inevitably occurs are diversifying livelihoods, utilizing locally available food sources, maintaining applicable Javanese norms and customs as well as high utilization of social capital among small-scale fishermen. Conflict resolution among small-scale fishermen is usually carried out by simply being silent and forgotten over time or through deliberations mediated through religious leaders, rich fishermen (upper layer), and wise old fishermen. The dynamics of conflicts that occur among small-scale fishermen do not appear much because the existing conflicts are more latent.

The south coast of Java is famous for its high waves and many troughs, so it is dangerous for fishermen. Therefore, the fisheries sector on the southern coast of Java is less developed than those on the north coast of Java. Fishermen must really understand the environment on the coast. One of the beaches on the south coast of Java with a harbor is Sadeng Beach. Many working fishermen catch fish with a profit-sharing system with fishermen who own boats due to limited capital. This study aims to determine the survival strategy, environment and profit-sharing system for working fishermen in Sadeng Beach. The research method used is a case study. The results show that Sadeng fishermen have survival strategies such as diversification in fishing gear, optimizing weather technology, having side jobs, helping each other, and joining the fisherman group. To maintain business continuity, fishermen work with a profit-sharing system. The passion to live and work hard as a fisherman makes them strong and continue to be passionate until this day.

The Batavia – Bandung rail way is part of the construction of the main rail way on the island of Java which connects the west coast with the east coast of Java. This rail way is also a link between Priangan and Tanjungpriuk port on the north coast of Java, and the port of Cilacap on the south coast of Java. This paper aims to describe the reasons for the construction of the Karawang – Padalarang rail way and the railway facilities built on this route. The method used to answer these problems is descriptive analysis method with a chorological approach. The construction of the Karawang – Padalarang route was an effort to shorten the distance and speed up the journey of Batavia Bandung, even though it had to overcome natural obstacles in the form of mountainous areas with deep and wide valleys and high hills. The condition of the natural environment of the natural environment requires the construction of long and high bridges and tunnels to penetrate the hills.

This paper discusses the differential social structure activities of Dutch Businessmen or VOC, Chinese Clerks and Javanese Shipowners. After the disintegration of the Mataram Kingdom in the 18th century, it had an impact on the economic activities of the middle class of non-European traders on the North Coast of Java. The decline of the maritime trade situation in the 17th century in Southeast Asia in general and in Java in particular was caused by the VOC's military economic monopoly intervention pattern and agrarian kingdoms that did not pay attention to trade shipping. This writing uses a qualitative method with a socio-historical approach. This writing uses Mahan's theory that a strong maritime state must have a strong navy. This can be seen how the VOC maximized the military potential of its navy in dominating trade shipping on the North Coast of Java. Since then Java has been characterized by a rejection of the weak merchant class. The king of Java's choice to pull the economic center to the south also influenced the VOC's trade dominance on Java's North Coast. However, the economic pressure of the VOC slowly led to the emergence of a middle class that came from outside the rule of the royal class. This middle class was filled by Madurese captains alongside Javanese Nahkoda, as well as Chinese merchants, for the latter were considered tenacious despite often having strong trade relations with the Dutch or the VOC marking the discourse on the dynamics of trade and shipping in port cities on the North Coast of Java.

Global warming causes more carbon dioxide (CO2) emissions. The mangrove forest is one of the world’s largest carbon sinks, as it is capable of storing and absorbing CO2 more than other forests. This research aims to determine carbon storage and CO2 sequestration at various zones of mangrove forests on the Wulan Delta, i.e. pond, river, and coastal zone, also determine the potential of delta ecosystem in North Coast of Java in reducing CO2 emissions with Wulan Delta as the sample. Systematic and non-destructive sampling method was used by measuring the Diameter at Height Breast (DBH) of mangrove trees with a diameter of >5 cm inside plot areas of 10 m x 10 m each, and the measurement result was then calculated based on an allometric equation. The mangrove forest of Wulan Delta has the above-ground of carbon density 245.578 ton C/ha, root carbon density of 100.778 ton C/ha, and soil carbon density of 42,991.169 ton C/ha. It sums up to the total carbon storage of 9,171,845.27 ton C and CO2 sequestration of 33,660,672.12 ton CO2 with an annual sequestration value of 1,530,030.55 tons CO2/year. The CO2 sequstration results are then compared with the delta in North Coast of Java with extrapolation method. The results obtained that Delta in North Coast of Java can absorb CO2 national emissions in 2018 by 3.416x10−6 CO2/year.