bluuebunny/crossref_metadata_2025 huggingface dataset:
Lithium Extraction from Geothermal Brine Using Electrodialysis Method
Authors: Jati A D , Sujoto V S H , Sutijan  , Petrus H T B M , Mulyono P
Published: October 2023

The global market share of electric vehicles is expected to increase significantly. The lithium-ion battery is one type of battery that can power electric vehicles because light, inexpensive, has a high energy density, and has a long service life. Lithium may be obtained economically from hard rock ores and brines. Indonesia has a huge geothermal potential and lithium concentration in geothermal brine can reach 70 mg L−1. With the high concentration of lithium in brine, this is a great opportunity for Indonesia to produce lithium independently. The separation of lithium from brine can be separated by various methods. One method that has high effectiveness is by using the electrodialysis method. This study will extract lithium from geothermal brine with the electrodialysis method using monovalent membranes. Anion exchange membrane (AEM) and cation exchange membrane (CEM) are used in this system. The recovery solution to collect lithium from brine is HCl 0,1 M. We variate the voltages (2 volt and 3 volts) to see the effect on flux and conductivity. From the experiment, the 3 volts give more flux and conductivity than the 2 volts. The 3 volts has 10 mL cm−2 h−1 of flux and 2110 μS cm−1 of conductivity while the 2 volts has 4 mL cm−2 h−1 of flux and 1770 μS cm−1 of conductivity. The higher voltages given to the system, the easier separation can be done.
Mineralogical Distribution and Characteristics of Fe-, Ti-, and V-Bearing Beach Ironsand Deposit in Adikarto Bay Kulonprogo, Yogyakarta, Indonesia
Authors: Harahap L M L , Idrus A , Ernowo  , Sukadana I G , Suwahyadi  , Handayani T
Published: October 2023

Identification of beach sand deposits was carried out in the south coastal area of Adikarto Bay, Kulonprogo, Yogyakarta in Indonesia. A total of 25 points were observed to identify the characteristics and mineralogy of beach sand related to the iron (Fe), titanium (Ti), and vanadium (Fe) bearing minerals that have an important role in the transition of fossil energy into clean energy as an energy storage technology known as Vanadium Redox flow batteries (VRBs) and lithium-vanadium-phosphate batteries [1]. Laboratory analysis was performed by mineral grain analysis, ore microscopy, and micro-XRF. Based on the mineralogical analysis, the beach sand deposit is composed of heavy minerals (magnetite, titanomagnetite, and hematite) and light minerals (quartz, clinopyroxene: hedenbergite and augite), biotite, hornblende, and ilvaite. The results of the analysis show that the distribution of heavy minerals is dominantly in the fraction size <0.106 mm (70-80%,) while light minerals are distributed in the fraction size 0.212-2 mm (80-90%). Mico-XRF for elemental analysis identification shows that magnetite is the mineral bearing of Fe, Ti, and V elements with a percentage of (79.02 - 92.43 wt%), Ti (6.08-7.89 wt%), and V (0.56-1.15 wt%). Therefore, it is important to characterize the mineralogy and distribution of magnetite, since it can be used as a “mineral pathfinder” for advanced exploration of Fe, Ti, and V elements. So, the ironsand is for the cement indsutry and has advanced utilization.
Real Time Monitoring Using Robotic Total Station on the Outlet Slope of the Cisumdawu Tunnel, West Java
Authors: Prasetya R B , Hendarto H
Published: October 2023

Slope failure is still possible even though the slope has been designed and reinforcement has been carried out, as an example the slope of the Cisumdawu Tunnel Outlet which collapsed in October 2021. Therefore, monitoring technology is needed to anticipate slope collapse. In this study, the repaired slopes of the Cisumdawu Tunnel Outlet was monitored using a Robotic Total Station (RTS) to measure surface displacement in real time. Monitoring using RTS was carried out for approximately 40 days. The purpose of this study is to determine value and characteristic of slope displacement using an empirical approach from previous researchers. The displacement starts April 23rd at night until it reaches stability on April 24th 2022. The most significant displacement occurred in the prism target 08 which is located in the foot of slope and between the twin tunnels. It has 8 mm longitudinal displacement, the transverse displacement is 0.8 mm and the height has dropped by 13 mm. Almost the rest of the prism is in a stable state. From this study, the slope movement class is found to be regressive and categorized as velocity < 15 mm/day which is no failure expected within 48 hours. From this study, it was concluded that during the monitoring period using the RTS the outlet slope of the Cisumdawu tunnel was safe
Menoreh Mountain sustainable tourism development: a spatial outlook
Authors: Reinhart H , Rafida M R , Sofie T
Published: October 2023

Increasing development of geotourism and Geopark raises awareness of more environmental-friendly and sustainable tourism which can be approached using spatial analysis. This paper aims to connect the spatial element with sustainability tourism in Menoreh Mountain and formulate sustainable tourism development. Using Moran’s Index, this study examines the Geo-tourism site’s spatial characteristics and how the development should be done based on that analysis. For the result, 120 sites have been collected through Google Maps data and a field survey for validation. The sites comprise caves, waterfalls, pine forests, summits/peaks, and religious sites. By plotting the density of the tourism destination to a certain village, the Global Moran’s Index for it is 0.318. The Univariate Local Moran’s I show 10 villages in the High-High quadrant, 4 villages in the Low-High quadrant, 3 villages in the High-Low quadrant, and 2 villages in the Low-Low quadrant or cluster. Based on the spatial pattern, it is crucial to focus on the characteristic of each quadrant to establish sustainable tourism comprising economic and geological, and ecological sustainability and strengthen the spatial policy. The characteristics of each cluster also become a basis for developing strategies regarding the administrative division of Menoreh Mountain.
The Linkage of Rainfall Anomaly due to El Nino Southern Oscillation (ENSO) on Cassava Productivity in Central Java Province
Authors: Firmansyah Anugrah Jorgi , Nurjani Emilya
Published: October 2023

El Nino Southern Oscillation (ENSO) is a global climate phenomenon that affects the climate of a region and causing climate anomalies. ENSO can cause rainfall anomalies that have an impact on the agricultural sector. Cassava is one of the plants known as climate-resistant plants. Cassava has high productivity and is almost evenly distributed in Central Java Province. This study aims to determine the relationship between rainfall anomalies due to ENSO and cassava productivity in Central Java from 1990-2019 at each different ENSO phase. El Nino in weak, moderate, and strong phases triggers a decrease in annual rainfall intensity with an even distribution from the north and becomes softer towards the south of the province. When La Nina begins, the intensity of rainfall increases with a strong intensity starting from the south side and weakening towards the province’s north. The increase in rainfall during the La Nina phase tends to increase cassava productivity and the El Nino phase tends to decrease cassava productivity, although there are case findings in certain areas.
Dynamics of Land Use Change and The Relationship with Food Sufficiency in Pacitan Regency
Authors: Pramesti Revia Ardyaning , Harini Rika
Published: October 2023

Infrastructure development in an area affects changes in existing land use, one of them to meet demand in development. Agricultural land use change can affect agricultural production and productivity. This study aims to determine the conditions of land use change and food sufficiency in Pacitan Regency and the relationship between the two variables. The data used in the analysis are data on land use and food production from 2009-2017 to calculate food sufficiency. The research method is quantitative descriptive with Pearson correlation statistics. The results showed that agricultural land use in Pacitan Regency was dominated by dry land agriculture. Paddy fields and dry land agricultural have decreased, while non-agricultural land has increased. The food sufficiency of the four food commodities, namely rice, corn, sweet potatoes, and cassava, has fluctuated in recent years. However, the overall condition of food sufficiency from 2009-2017 decreased from 6.48 in 2009 to 5.04 in 2017. Based on the Pearson correlation test results in Pacitan Regency, there was no connection and significant relationship between land use change and food sufficiency. This result can occur due to an increase in population, changes in the cultivation of food crops into woody plants, changes, and a decrease in land productivity.
An Ecological Study of Karst Landscapes Around the Jalur Jalan Lintas Selatan (JJLS) of Gunungkidul Regency
Authors: Astuti B I D , Haryono E
Published: October 2023

JJLS is a newly constructed highway connecting the southern area of Java. Along the Gunungkidul Regency trace, the road crosses protected karst landscape of Gunungsewu. This study aims to analyze landscape change during 2005-2020 period after the construction of the highway. Landscape change was analyzed by using Spatial Landscape Impact Assessment (SLIA). The data used for this research were Landsat 7 ETM+ images, google earth images, and Sentinel 2A images. The result study shows that the construction of JJLS has changed the landscape structure within the radius of 100 road sides. The change is mostly land use and landforms duty cut and fill activity. JJLS Road construction produces a very high impact on environmental sustainability. The trickle down effect must be controlled in the future development in order to ensure not to deteriorate environmental and water resources.
Differences in soil-water characteristics of monoculture oil-palm plantations, agroforestry oil-palm plantations and natural forest
Authors: van Oosterhout M. J. , Marhaento Hero , Booij Martijn J , Ridho Darmawati
Published: October 2023

This study aims to determine the soil water retention curves and infiltration rates for three different land use types located in Jambi province, Sumatra, Indonesia: natural forest, monoculture and agroforestry oil palm plantations (divided into new agroforestry (2,5 years) and old agroforestry (over 10 years)). Data on the infiltration rate of the soil for the different land use types was collected by using a double infiltrometer. A Horton curve was fitted to these measurements. The results on the soil water characteristics were compared between all land use types. This concluded that there is a significant difference in constant infiltration rate between the value of the natural forest and the new agroforestry and the value of the other land use types. The forest also has a significant smaller porosity. The results of the study concluded that plantations have a bad influence on the soil characteristics investigated, but in general agroforestry has a less bad impact than monoculture. However, this is highly dependent on the features of the locations investigated.
Characteristics of entrenched meanders in catchment landscapes: a case study of Java, Indonesia
Authors: Raharjo Puguh Dwi , Haryono Eko , Anggri Setiawan M. , Permana Haryadi , Farisan Ardhan
Published: October 2023

The diversity of physiography on the island of Java reflects the existence of different landforms that have properties and characteristics in the interaction of river formation. Rivers respond to longitudinal profile deformation, one of which can form river meanders. Meander rivers in Java are formed on alluvial plains (free meanders) and in hilly areas (entrenched meanders). The meander river formation factor is the high flow volume, which can be seen from the morphometric conditions. This study aimed to determine the morphometric characteristics of water catchment in entrenched meander rivers on the island of Java, as well as its relationship with the geodynamic conditions. The method used is the identification of entrenched meander rivers on Java Island, and morphometric calculations are carried out; besides that, it is also associated with morphostructural conditions to determine the process of its formation. The results obtained that the catchment area of the entrenched meander river has a tendency for small volumes of water and relatively longer floods; this is different from the nature of the free meander. The morphostructure much controls the process of forming entrenched meander rivers.
Groundwater quality analysis using water quality index in Wonosari basin, Gunungkidul regency-Indonesia
Authors: Bagaskara R A , Widyastuti M
Published: October 2023

Wonosari Basin is a physiographical unit in Gunungkidul Regency, Indonesia, that has enormous groundwater potential. Limestone inside the basin and dense population can harm the environment. The research aimed to analyze the groundwater quality in the Wonosari Basin based on the applicable quality standards, determine the water condition using the Water Quality Index (WQI), and determine the spatial pattern of the WQI grade. The total sample used in this research is 21 samples. Total Dissolved Solid (TDS), pH, Iron (Fe), Manganese (Mn), Sulfate (SO4), Nitrate (NO3), Hardness (CaCO3), and Total Coliform values of the groundwater samples were inputted to the weighted arithmetic WQI using Microsoft Excell to analyze the water quality. The spatial analysis was carried out using the cross-tabulation method with Microsoft Excell. The water quality standard used in this research is Regulation of the Minister of Health of the Republic of Indonesia number 23 of 2017. The research result showed that total coliform is the only parameter that exceeds its maximum acceptable presence, WQI values indicate that most of the groundwater samples have good quality, and the spatial pattern of water quality follows the population density.
An Isotopic Approach to Investigate Seepage in Dam: Case Study Ciawi and Sukamahi Dry Dams, West Java, Indonesia
Authors: Dewi F K , Wilopo W , Azwartika I
Published: October 2023

Seepage control in the dam is vital in maintaining dam safety. It is important to determine the source of seepage water to be controlled so that there is no excessive seepage that threatens dam stability. This study used Physico-chemical parameters and stable isotopes (δ2H and δ18O) to determine groundwater characteristics, the groundwater origin around the dam, and the connectivity of the Ciawi and Sukamahi Dry Dam’s seepage with surrounding water sources. This research shows that the groundwater in the study area includes freshwater with TDS values varying from 62 ppm to 189 ppm and EC values from 62 μS/cm to 414 μS/cm. The results of stable isotope analysis showed that the composition of seepage and groundwater sources around the dams are around the local meteoric water line (LMWL); this indicates that groundwater is more influenced by rainwater. Comparing the composition of δ2H and δ18O showed that the seepage water from the two dams has the same genesis as springs in Sukakarya Village (MA02) and dug wells in Gadog Village (SG13). This information is beneficial in determining the handling of seepage in the Ciawi dan Sukamahi Dry Dams.
Flood characteristics analyses in the Jratunseluna river basin due to the impact of Kedungsepur national strategic area development
Authors: Hanifah N H , Mawandha H G , Abiy F , Setyawan C , Kesuma L M , Rulisyani D S
Published: October 2023

The area of the Jratunseluna river basin is categorized as a high-risk flood vulnerability. The urban development plan can worsen this condition through Kedungsepur national strategic area. The objective of this study is to identify flood characteristics in Jratunseluna river basin caused by the alteration of land use due to Kedungsepur national strategic area development through rainfall-runoff 2D simulation. The RRI 2D model was chosen because it could simulate flood inundation comprehensively in all river systems while the other models such as HEC-HMS, TOPMODEL, and Tank models have a limitation on it. The input data used for the RRI model were rainfall data, topography (DEM), and land use maps. The rain data used in the simulation was the Global Precipitation Measurement (GPM) from 2010 to 2020. The study results indicate that the flood risk level would increase during the implementation of the Kedungsepur national strategic area development. The flood duration and peak discharge increase mainly characterize the increase in flood risk. The most significant increase in peak discharge among the four outlets is obtained in the Garang watershed. In the case of a 2-year flood, the peak discharge increased by 44.91% from 262.18 m3/s to 379.92 m3/s and for the case of a 50-year flood, the peak discharge increased by 54.34% from 331.63 m3/s to 511.83 m3/.
Hydrological Potential Mapping to Generate Micro-Hydro Power in Code River
Authors: Hadi M P , Suarma U , Sumunar A A K , Girsang M R B
Published: October 2023

Fossil fuel energy utilization in Indonesia is consider high consisting of 65% coal sources and 20% fuel, while only 15% are generate from new and renewable energy sources. This number is critical due to the commitment to reduce greenhouse gases by 29% or 41% as declared Glasgow in 2021. Alternatives source of energy could be obtained from solar, wind, and water. The energy generate from those sources are consider intermittent, however, water utilization can be optimized by construct several weirs (small-scale reservoirs) to accumulate the rain water as a kinetic energy source to generate electricity. Only some part of the world, especially tropical Indonesia archipelago, has enough rain to generate energy. This research intends to measure the potency of Code River, representing small river in generating micro-hydro power. The Code River is representing a small river on the island of Java as part of the archipelago in Indonesia which has the characteristics of a river, a small water catchment area, and has high discharge input from rainfall because it is in the tropics. The weir is equipped with a penstock pipe, as water intake to the generator. The pipe inner diameter made of high-density polyethylene material can be 200, 300, 400, 500, 700, 800, 1,000 and 1,600 mm. Each pipe size can produce discharges of 0.42, 0.75, 1.62, 2.1, 3.1, 3.5, 6.0 and 24.0 m3/s respectively. The combination of discharge and head height will produce electrical energy (in watts). Based on hydrological modelling consisting of 52 sub-watersheds, the highest electricity production in 2021 is 8,359,218.3 kWh with 800 mm pipe size (3.5 m3/sec discharge). The electricity production is based on reliable discharge between 7-96% which is different for each weir location. In conclusion, the electricity supply for the whole year (100%) is inadequate
Typology of planned housing in the city of Yogyakarta
Authors: Widiyasuti D , Adhitama S Y , Ali B O , Aprillia B
Published: October 2023

This paper examined the planned housing in Yogyakarta City distributed in eight sub-districts, namely Umbulharjo, Tegalrejo, Wirobrajan, Mergangsan, Mantrijeron, Kotagede, Gondokusuman, and Jetis. Planned housing in Yogyakarta City can be classified into a gated community and a non-gated community. They were commonly identified based on the similarity and regularity of the buildings and the road network. The data was taken from their Building Permit (IMB; Izin Mendirikan Bangunan) from the year 2000 – 2019, Google Street View, Pleiades Satellite Imagery of Yogyakarta City in 2018, Google Map, and ArcMap base-map. Data analysis was undertaken by using satellite imagery, map interpretation, and quantitative analysis by using scoring technique to describe the score of typology. Most of the planned housing in Yogyakarta City are classified into Typology II, which had a medium-strength gated community characteristic. The typology was composed based on the physical-geographical and social-economic indicators. Most of them were more than 10 years old and were provided with walls/fences and portals to restrict outsiders’ access. The residents were classified into middle-class based on their social-economic status. Most of the planned housing in Yogyakarta have gated-community characteristics based on these features.
Association of mollusks and seagrass plants in Miang Besar Island, Kutai Timur Regency
Authors: Kaharuddin  , Imanuddin  , Harmiati
Published: October 2023

This research to determine the level of associet between mollusks and seagrass plants on Miang Besar Island. this research was conducted in june 2020 using random non sampling method consisting of 12 sampling points. For the retrieval of seagrass and mollusk data using the method of transek squares measuring 1x1 m2. testing the association between 2 types using. Contingency table 2 x 2 to determine the association level between 2 species with the Jaccard index. The association between seagrass and mollusk species was analyzed into 3 groups. positive associations are 31 pairs, negative associations consist of 30 pairs and unrelated associations consist of 35 pairs.
Public participation in beach clean-up activities to raise awareness and reduce marine litter for the protection of the Black Sea ecosystem
Authors: Ismail N P , Erüz C , Karakoç F T
Published: October 2023

Human activities and poor awareness are believed to be responsible for marine litter pollution. In the scope of the European Union, Cross Border Cooperation, and Black Sea Basin (EU, CBC, BSB - 785) LitOUTer Project, “Raising Public Awareness and Reducing Marine Litter for the Protection of the Black Sea Ecosystem”, beach clean-up activities have been conducted. A beach clean-up activity was conducted at the Kıyıcık Beach, Trabzon, Turkiye involved by Stakeholders, NGOs, middle to high school, university students, teachers, and lecturers. This study aims to reveal the amount of marine litter at Kıyıcık Beach through public participation in beach clean-up activities. A total of 4488 solid wastes (∼100 kg) were collected and removed from the beach. The waste composition consisted of 50% plastic, 22% metal, 10% glass, 8% paper, 4% cloth, 1% metal, and 4% Covid-19-related waste. Plastic pieces, plastic bottles, and caps dominated the plastic litter on the beach. Moreover, 119 single-use face masks (Covid-19-related waste) were collected. Single-use plastic waste in the environment implies the impact of human activities and a lack of awareness regarding marine litter. Public participation in beach clean-up activities is expected to raise individual awareness and reduce marine litter to protect the Black Sea Ecosystem.
Nutrients and chlorophyll-a concentration in Socah Estuary receiving shrimp pond waste, Bangkalan Regency
Authors: Kartika A G D , Jayanthi O W , Nuzula N I , Syaifullah M , Siswanto A D
Published: October 2023

This study investigates the nutrient content, water quality, and its relationship with chlorophyll-a in the Socah Estuary, Bangkalan Regency. The research was conducted in four stations. Determination of nitrate and nitrite in samples was performed by the colorimetric method. Meanwhile, phenate and Nessler reagent spectrophotometric methods were used to determine the ammonia and ammonium content in samples, respectively. The phosphate and chlorophyll-a were determined using ascorbic acid and spectrophotometry, respectively. The Spearman rank correlation was used to measure the degree of relationship between nutrients and chlorophyll- a content. Based on the results of Spearman rank correlation, the nitrate showed the strongest correlation (rho = 0.76) compared to other nutrients. Moreover, the increased chlorophyll-a level in the water will be closely related to the increased nitrate level. According to the value of Secchi depth, nutrients, and chlorophyll-a concentration, eutrophic is a trophic state in Socah Estuary. This condition is caused by the input of shrimp pond wastewater which triggers nutrient enrichment, decreasing the water quality and increasing the phytoplankton biomass in Socah Estuary.
Multibeam echosounder backscatter strength analysis for seafloor sediment identification in Damar Besar Island Waters, Thousand Islands
Authors: Arifah S N , Manik H M , Mulyadi D S
Published: October 2023

The condition of the Indonesian territory surrounded by the ocean requires technology to obtain seabed information to support the development of social, economic, and security activities. One of the technologies that can be used is the multibeam echosounder (MBES) hydroacoustic technology. MBES can scan seabed in a wide range, resulting in bathymetric data and backscatter values. The value of backscatter can be used to identify seafloor sediments. This study compared backscatter intensity values obtained from the MBES survey to the previous study. After identifying the sediment, the data obtained are mapped to produce a sediment distribution map. The types of sediment identified in the Damar Besar Island Waters are fine silt, medium silt, coarsed silt, silty sand, muddy sand, clayed sand, very fine sand, and fine sand with a range of backscatter values from -34,92 to -19,04 dB. Fine sand sediments are nearby the northern island while muddy sands and silty sands are scattered away from the island.
Side scan sonar data quantification for seabed classification in Yos Sudarso Bay, Jayapura
Authors: Salsabila A S , Manik H M , Mulyadi D S
Published: October 2023

Side Scan Sonar (SSS) is an instrument that is usually used in surveys to perform seabed imaging. SSS was able to show two-dimensional images of the seabed with contour, topographic, and target conditions simultaneously. This technology is capable of distinguishing seabed types such as rocks, sand, or others. In addition, the usefulness of this technology can also detect the existence of marine pipes and cables, shallow structures of the seabed, dredges, environmental studies, military, archaeology, fisheries, and mining. The aims of this research were to identify and interpret the seabed, measure the acoustic backscatter (dB) and amplitude (mV) of the seabed substrate, and compute SSS data using Continuous Wavelet Transform (CWT) in the Yos Sudarso Bay, Jayapura. Processing data was performed by radiometric Beam Angle Correction (BAC), Automatic Gain Control (AGC), and geometric (bottom tracking) corrections using SonarWiz 7 software. Pre-processed SSS data were then converted to XtfToSegy and the amplitude values were exported by SeiSee software, and CWT was calculated using Matlab. Amplitude data was visualized using Microsoft Excel to display a relation between amplitude, time, and CWT graph. The results of seabed detection were three areas of sand and one coral target. The amplitude value of sand 1 ranged from 4319 to 30976 mV with the = backscatter value was -17.10 dB. The amplitude value of sand 2 ranged from 1411 to 12288 mV with the backscatter value was -18.79 dB. The amplitude value of sand 3 ranged from 1391.625 to 12032 mV with the backscatter value was -18.70 dB. The amplitude of the coral ranged from 24960 to 32640 mV with the backscatter value was -2.30 dB. The CWT analysis results show that the yellow-coloured coral’s energy represents a rougher and harder object. The energy generated from the blue-coloured sand represents the object has smooth and non-hardening characteristics.
Suitability Index of Snorkeling Tourism In Sepulu District, Bangkalan, Indonesia
Authors: Nugraha W A , Insafitri
Published: October 2023

Bangkalan is one of the districts in Madura with a coastal area that can be developed as a marine tourism location for snorkelling, and their northern coast facing the Java Sea has only been used for coastal tourism. This research aimed to assess the suitability index of snorkelling tourism in Sepulu waters, Bangkalan. The research was carried out during September–October 2021. Coral cover, fish diversity, water conditions, and an analysis of tourism suitability and the carrying capacity of snorkelling tourism were assessed. Hard coral cover in Sepulu waters ranges from 22-38%, while the per cent of coral cover (including soft corals) ranges from 34-55.5%. The number of coral growth forms found in Sepulu waters ranged from 6-8 forms. Reef fish found in Sepulu district water were between 7-12 species. The tourism suitability index of Sepulu Waters, Bangkalan, which ranges from 61.40 – 75.44%, is included in the category of quite suitable. The area’s carrying capacity for snorkelling tourism activities is 152-500 people daily. Sepulu waters, especially Tengket and Labuhan waters, have a high potential to be used as snorkelling tourism objects.
The response of tuna to ocean acidification in Indonesian waters (Case study: Gulf of Bone)
Authors: Tito C K , Susilo E , Sasongko R D
Published: October 2023

There is growing concern about ocean acidification (decrease in pH of the ocean as a result of increased atmospheric carbon dioxide absorption by ocean) as one threat of climate change that may have significant impacts on marine organisms, such as fish. Recent studies suggest that adult fish are not directly impaired by OA, however, for the earliest fish stages, a number of direct effects have been observed. Hence, we observed the response of OA on monthly larvae density of yellowfin tuna in the Indonesian water, especially in the Gulf of Bone. The pH on the total scale (pH) and surface aqueous partial pressure of CO2 (pCO2) data were derived from Copernicus Marine Environment Monitoring Service (CMEMS) model product; meanwhile, fish data from 2014-2016 were derived from daily Infrastructure Development for Space Oceanography (INDESO) tuna population model outputs. This study indicates that the variability of pCO2 tends to increase while the pH tends to decline. During the northwest monsoon periods, pH in the Gulf of Bone tends to be lower. The larvae and juvenile of yellowfin tuna in the Gulf of Bone waters have various spatial correlations with pH and pCO2. Both have the potential to decrease with the declined pH and elevated pCO2.
Historical trend of heavy metals in mangrove sediment from Nusa Lembongan, Bali using 210Pb-geochronology
Authors: Lubis A A , Sugiharto U , Putra A D P , Shintianata D
Published: October 2023

Mangrove sediment is a natural filter for retaining pollutants before entering the coastal area and ocean. This study collected sediment cores from a Marine Protected Area (MPA) in Nusa Lembongan, Bali, to establish 210Pb geochronology and heavy metals records. Alpha spectrometry and Instrumental Neutron Activation Analysis (INAA) were used to determine 210Pb and heavy metals (Co, Cr, Fe, Hf, Sb, Sc, Se, and Zn), respectively. The Contamination Factor (CF), Enrichment Factor (EF), and Geo-accumulation Index (I_geo) were assessed. The result shows that 210Pb provided records of sediment accumulation spanning approximately 100 years. The vertical profiles of all heavy metals from the 1910s to the 1930s were slightly constant. From the 1930s to the 1990s, the profiles of Co, Cr, Hf, Sb, Sc, and Zn slightly increased; meanwhile, Fe and Se were slightly constant. From the 1990s to 2017, all heavy metals decreased gradually. Based on the CF, heavy metals Cr, Hf, Sb, Sc, and Zn were categorized as moderate contamination, and Co, Fe, and Se were low contamination. The average EFs of all heavy metals suggested their origin was derived from crustal material. In the I_geo index, only Sb was classified as moderate pollution, while the other heavy metals were not pollutants.
Morphometrics and long-weight relationship Halmahera walking shark (Hemiscyllium halmahera, Allen, 2013) population in Morotai Island Sea, North Maluku, Indonesia
Authors: Akbar N , Bengen D G , Nurjaya I W , Natih N M N , Madduppa H H , Subhan B , Wahab I , Baksir A
Published: October 2023

Morotai Island is under the influence of plates, Indonesian Throughflow, Halmahera Eddy, New Guinea Coastal Undercurrent (NGCUC) and is located in the coral reef triangle. Halmahera walking shark (Hemiscyllium halmahera) was found in the Morotai Island Sea. The aim was to study the morphometric and length-weight relationship of H. halmahera on Morotai Island. Sample collection of H. halmahera in South Morotai, North Morotai and South West Morotai. H. halmahera samples were taken using scuba diving at a depth of 3-10 meters. The morphometric measurements were 11 variables TL (total length)- LTL (lower tail length). The diversity of morphometric characteristics found was analyzed using the Principal Component Analysis (PCA) method. Analysis length-weight relationship using linear regression equation. The results found 30 individuals (South Morotai = 8, North Morotai = 9, South West Morotai = 8, and East Morotai = 5) and the frequency of sex presence individuals (male = 16 and female = 14). Morphometric parameters found variation in each individual. PCA analysis found that the distribution of morphometric characteristics had body size variation. Dendogram is divided into Cluster I (North Morotai dan South West Morotai) dan Cluster II (South Morotai dan East Morotai). The length-weight relationship found negative allometric growth.
Analysis of high waves and coastal flooding event in Manado in mid-January 2021 (meteotsunami perspective)
Authors: Firdaus Randi , Mawarni Cecylia Putri , Sinurat Maya Eria
Published: October 2023

Meteotsunami is atmospheric-induced ocean waves at the frequency of tsunami waves (2 minutes-2 hours). On January 17, 2021, the high waves tsunami-like due to lousy weather superimposed with the high tide were reported hitting the coastal area of Manado City, North of Sulawesi. This research examined the characteristic of that tsunami wave-like phenomenon. The sea level, atmospheric data (i.e., wind and air pressure), and weather satellite imagery were used in this study. The sea level, air pressure, and wind data were filtered to remove the low-frequency signal to obtain the amplitude of the high-frequency signal. The results showed that a high-frequency sea level signal’s maximum wave height (peak to trough) is up to 0.4 m. This condition responded to the increase in high-frequency maximum wind speed reaching 11 m/s associated with the convective system, such as the Cumulonimbus cloud system, detected 10 hours before the maximum high-frequency sea-level event. These circumstances meet the meteotsunami criteria, but the other parameter, such as air pressure, is not.
Identification of seagrass beds using high-resolution satellite imagery to basic inventory data supporting coastal ecosystem management (Case study: Lancang Island)
Authors: Sugara A , Kurniawati E , Nurholis  , Nurul Suci A N
Published: October 2023

Seagrass habitat is an important element of the coastal marine ecosystem, as it influences all major fields in the coastal environments. Due to anthropogenic and natural pressure, such identification of habitat distribution becomes crucial. Remote sensing can provide the best solution regarding time and cost to extract seagrass beds’ spatial and temporal information. When the low spatial resolution satellite image provides low accuracy and high uncertainty of seagrass distribution, we assess the high spatial resolution image product, the WorldView-2 image, to identify the seagrass bed distribution in Lancang Island. We confidently found that higher resolution images could leverage the mapping quality, especially on the seagrass beds, which could be highly sensitive to miss-detection. We can produce 83,75% overall accuracy using pixel-based classification; this is better among other low-resolution images for Instants, Landsat, and Sentinel. Our results suggest that the WorldView-2 image could perform better on seagrass beds identification, yet further improvement on more robust classification methods and algorithms could amplify the mapping and monitoring strategy. Based on this, it can be used as basic data to support future coastal ecosystem management on Lancang Island.
Analysis of suitable site for seaweed aquaculture development in the Indonesian Sea (a case study of Fisheries Management Region-713), with the application of numerical model data
Authors: Rintaka W E , Berlianty D
Published: October 2023

Seaweed is an excellent product for cultivation in Indonesia therefore the expansion of seaweed aquaculture is crucial to be supported by the availability of data and accurate information. The Republic of Indonesia’s Fishery Management Region-713 (IFMR-713) has the potential for the development of seaweed cultivation. This study aims to conduct a spatial analysis of suitability for the development of seaweed cultivation using numerical models data based on multi-criteria evolution (MCE) in the IFMR-713. The primary data used for the analysis are (1) physical geographical parameters (includes: bathymetry, wave height, and current) and (2) water quality parameters (contains: temperature, salinity, pH, phosphate, and nitrate). The potential seaweed cultivation area in IFMR-713 is 63,125 km2 (13.12%) of the total area in IFMR-713 (481,300 km2). We also found that the local community utilized only a minor part of the very suitable area categorized for cultivating seaweed (based on data and information from each Local Government), so there is still an opportunity to develop the utilization into the very appropriate category. However, it is recommended that its use should be based on environmental methods and adapted to the coastal spatial plan to be used as an essential foundation to support the application of ecosystem-based fisheries.
Spatial study of total suspended solid (TSS) for shrimp catching areas based on changes in watershed land cover and oceanographic factors in Ciletuh Bay 2017 – 2021
Authors: Sukmawati D , Supriatna  , Rustanto A
Published: October 2023

The TSS in Ciletuh Bay originates from the Ci Leutuh and Ci Marinjung estuaries. This study aimed to analyze the effect of changes in watershed land cover and oceanographic factors (salinity, bathymetry, sea surface currents) on the distribution of TSS and the relationship between TSS and shrimp catch activity. This research uses remote sensing method, Budhiman Algorithm for TSS, Cilamaya Algorithm for salinity, and Maximum Likelihood Classification for watershed land cover. The results show that sea surface currents and changes in watershed land cover (forest, bare land, and shrub) affect the distribution of TSS in Ciletuh Bay. The relationship between TSS with salinity and bathymetry is negatively correlated. The existence of TSS in Ciletuh Bay causes the dominance of muddy waters so that it becomes a habitat for various types of Penaeid shrimp. The types of penaeid shrimp that are mostly caught in Ciletuh Bay are rebon shrimp and endok shrimp.
Potential extract of brown algae Sargassum sp. and Padina sp. as antibacterial Vibrio harveyi
Authors: Assegaf M , Insafitri
Published: October 2023

Vibrio sp. in shrimp farming ponds cause infection with Vibriosis which results in crop failure. Various efforts have been made, such as the administration of antibiotics derived from chemicals that can cause resistance to bacteria. One of the other efforts that can be done is to use marine organisms as natural antibacterial agents, such as brown algae of the genus Padina and Sargassum which have antibacterial activity. The purpose of this study was to determine the best concentration of Sargassum sp. and Padina sp. in inhibiting the growth of Vibrio harveyi bacteria and knowing which brown algae extract was more effective in inhibiting the growth of V. harveyi bacteria. The extraction process was carried out using the maseration method with methanol as a solvent. Testing of antibacterial activity using agar diffusion method. The results showed that the extract of brown algae that was more effective in inhibiting the growth of V. harveyi was Padina sp., because the six treatments and positive control at 3 times of observation showed a clear zone that was greater than that of Sargassum sp. The best concentration of Sargassum sp. and Padina sp. in inhibiting the growth of V. harveyi bacteria was at a concentration of 2000 ppm for Sargassum sp. with the resulting inhibition zone of 18.2 ± 1.15 and 2000 ppm and 3000 ppm for the extract of Padina sp. with the resulting inhibition zones of 19.2 ± 2.75 and 19.5 ± 2.35. The resulting inhibition zone falls into the category of strong inhibitory activity.
Microplastic contamination in sediment and Strombus sp. on Bintan Island, Indonesia
Authors: Idris F , Rajib  , Hidayati J R , Febrianto T , Nugraha A H
Published: October 2023

The high level of public plastic consumption can trigger the increase of plastic and waste in marine areas. Plastic floats in the ocean will then be degraded into smaller sizes (<5 mm), namely microplastics. Microplastic can be dangerous to marine environments, especially to natural resources, including sediment and marine biotas., where microplastics are easily eaten by diverse marine biota. Bintan Island is a conservation area with abundant seagrass and associated biota resources, especially Strombus sp. This study examines microplastic contamination in sediment and Strombus sp. on Bintan Island, Indonesia. Samples (Strombus sp.) were collected from a 100 x 20 meter seagrass area, while sediment samples were taken in a 1 m x 1 m quadrant. The sediment was dried, and the biota was dissected to see the presence of microplastics. All microplastics collected from both samples were identified in shape and colour. The results showed that microplastics had been found in sediment and Strombus sp. Based on the characteristics of microplastics, the highest abundance of colour found was white, while the highest abundance of types found was a fragment
Environmental suitability and detection of cnidarian invasive species at Dumai and Kuala Tanjung Port using eDNA
Authors: Hartanto M T , Lestari D F , Sitanala E Y , Riyanto M
Published: October 2023

The Malacca Strait is Indonesia’s most strategic traffic lane to support ship logistics activities. Ships with ballast water transfer systems can raise water quality issues, distribute foreign microorganisms, or introduce invasive species globally. Phylum Cnidaria has a strong potential to invade waters because all species in this phylum have nematocysts that function to penetrate toxins. This study aimed to determine oceanographic conditions and identify invasive species in the phylum Cnidaria based on eDNA approaches in the waters of the Rupat Strait and Kuala Tanjung Port. Sample identification found 114 species of Cnidaria at Dumai Port and 112 species at Kuala Tanjung Port. Fertility waters were detected to have mesotrophic status at Dumai Port and Eutrophic at Kuala Tanjung Port. Based on the Global invasive species database, we found Ectopleura crocea and Pelagia noctiluca, native to the Mediterranean Sea and North Atlantic Ocean. Environment parameter conditions support the existence of invasive species in both study sites.
Detection and identification of Red Snapper (Lutjanus gibbus and Lutjanus malabaricus) and grouper (Plectropomus leopardus and Plectropomus maculatus) with deep learning
Authors: Purnadi N F , Jaya I , Iqbal M
Published: October 2023

The Indonesian fishing industry is a major global contributor, particularly in the production and export of snapper and grouper fish. These two groups of fish are known for their high diversity, but distinguishing between the different species can be challenging due to their morphological similarities. In order to overcome this challenge, this paper proposes the application of deep learning methods to identify the two major species of snapper and grouper accurately. The deep learning framework utilized in this study is Detectron2, a state-of-the-art object detection and segmentation model. The datasets used in the study consist of 500 images each for the snapper species Lutjanus gibbus and Lutjanus malabaricus, and the grouper species Plectropomus leopardus and Plectropomus maculatus, totaling 2000 images. The datasets were labeled using Coco Annotator software with a focus on species segmentation. The labeled datasets were then trained using Google Collaboratory, resulting in an accuracy value of 89.51%, a precision of 87.69%, a recall of 99.85%, and an F1-score of 93.38%. These results demonstrate that, even with a relatively limited number of datasets, it is possible to accurately identify the Red Snapper Lutjanus gibbus and Lutjanus malabaricus, as well as the grouper species Plectropomus leopardus and Plectropomus maculatus using deep learning methods. In conclusion, this paper demonstrates the potential of deep learning methods, specifically Detectron2, in accurately identifying snapper and grouper species. The results of this study suggest that this technology can be used to improve the accuracy and efficiency of fish species identification, which could have significant implications for the fishing industry and marine conservation efforts.
Sea level rise implication on small islands in Kepulauan Seribu, Jakarta
Authors: Pasaribu R. A. , Ratna Suhita N. P. A. , Gumilar G. , Choiriyah N. , Siregar R. R. , Yonatika N. O.
Published: October 2023

The phenomenon of sea level rise is caused by global warming, which impacts inundation in coastal areas, especially on small islands. The coastal area of small islands is very vulnerable to the impact of sea level rise, including Lancang Island (covers Lancang Besar and Lancang Kecil Island), Tidung Kecil Island, and Pramuka Island, which is part of small islands in Kepulauan Seribu, Jakarta. Sea level rise will become a problem if the seawater reaches land and causes environmental damage in coastal areas. Therefore, this study aims to create a vulnerability map for all those small islands due to coastal inundation using GIS technology. Analysis of areas affected by coastal inundation is carried out by processing DTM data derived from drone data. Based on 29 years of sea level rise data with the highest tide model, coastal inundation in 2050 is predicted to occur on all those small islands in Kepulauan Seribu and can be appropriately modelled. The results show that the affected areas on Tidung Kecil Island, Lancang Island, and Pramuka Island sequentially were 6.06 ha, 7.41 ha, and 3.47 ha. Some areas affected by coastal inundation on the three islands generally include dock and resident areas, empty land, vegetation, mangroves, forest, and road access. Mitigation efforts that can be carried out to reduce the impact of sea level rise in coastal areas include building embankments on the shoreline, dams, drainage systems, and mechanical wetlands, which must be optimized by increasing public awareness of coastal flooding.
Distribution of marine sponges based on depth area of Mesophotic Coral Ecosystems (MCEs) in North Lombok Waters, NTB Province
Authors: Arafat D , Bengen DG , Naulita Y , Subhan B , Yuliana FF , Saputra RR
Published: October 2023

North Lombok Waters have a fairly high level of diversity. Mesophotic Coral Ecosystems (MCEs) are light-dependent coral reef communities ranging from 30-40 meters and extending to the bottom of the photic zone to a depth of 150 meters. Sponges are the main constituent of MCEs that have many benefits, but their existence is poorly understood. This study aims to determine the distribution of marine sponges in Mesophotic Coral Ecosystems (MCEs). Data was taken in September 2020 using the Underwater Photo Transect (UPT) method. Pictures were taken at a depth of 10, 20, 30, 40, and 50 meters at 3 stations. Macroscopic identification of sponges based on underwater photos. The identification results found 32 genera of sponges spread over 3 stations in the waters of North Lombok. The deeper you go, the more genera are found at the three research stations. Out of 32 genera, sponge abundance dependent on depth only influences 5 genera. We anticipate additional factors affecting the 27 genera of sponges, but further research is necessary. The ANOVA test results showed that several sponges genera were significantly different between depths, namely Callyspongia, Theonella, Clathria, Stylotella, and Spirastrella.