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Jurnal Kelautan Tropis
Published by Universitas Diponegoro
ISSN : 14108852     EISSN : 25283111     DOI : -
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Articles 435 Documents
Abundance and Diversity of Coral Reef Megabenthos in Karimunjawa Islands, Central Java Wijaya, Aditya Surya; Haryanti, Dwi; Ramadhan, Muhammad Fadhilah; Wijayanti, Diah Permata
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i1.24514

Abstract

Karimunjawa is an archipelago which has a large coral reef area. However, the human and natural factors that put environmental pressure on coral reef ecosystem in recent years have caused the need to update data on the abundance and diversity of megabenthos in Karimunjawa. Data collection was carried out on 9 islands in Karimunjawa out on 30 September-4 October in 2023. The megabenthos data collection method was carried out using the belt transect method with data collection carried out at the family level in the survey area. The method for collecting data on hard coral cover was underwater photo transect (UPT). Megabenthos data analysis was carried out using Microsoft Excel software Coral Point Count with Excel Extensions (CPCe) software for coral cover analysis. Analysis of megabenthos data also includes ecological indices consisting of the Shannon-Wiener diversity index, Pielou evenness index, and dominance index. The relationship between hard coral cover and megabenthos was sought using simple regression analysis. The research results found 8 megabenthos classes and as many as 16 families. The results showed a weak relationship between megabenthos abundance and hard coral cover (r=0.03), but a strong and moderate relationship with the megabenthos ecological index (r=0.434 to 0.568). The regression analysis showed that there was no significant influence between hard coral cover and the abundance and ecological index of megabenthos (P>0.05).  
The Growth Pattern of Nyale Worm (Eunice, sp. Polychaeta) From Pahiwi Coastal, Sumba Island, Indonesia Njurumana, Steven Nggiku; Widianingsih, Widianingsih; Hartati, Retno; Ginzel, Fanny Iriany
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i1.24862

Abstract

Nyale (Eunice sp) is a polychaeta worm that belongs to the Phylum Annelids. Nyale (Eunice sp) appeared only once on Pahiwi Beach, West Sumba. Its appearance is often associated with the traditions of te west Sumbanese people. Nyale’s growth pattern is not yet known, so this research aims to determine Nyale’s growth pattern. Nyale samples were taken in the morning before sunrise by hand picking at the location of Pahiwi Coastal Waters, West Sumba. Based on the analysis results, the growth pattern of the Nyale is negative allometric, with a value of b=1.05. the correlation value obtained from the relationship between length and weight is 0.68. this also shows that an increase in length and weight.
Lead (Pb) Contamination in Sediments and the Potential of Gastropods as Bioindicators of Pb in Mangrove Forests, Mojo Village, Pemalang Latupeirissa, Cherokee Mikha-El; Haryati, Ani; Winanto, Tjahjo; Fikriyya, Nabela; Prihatiningsih, Isnaini; Januar, Hedi Indra; Putri, Wike Ayu Eka
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i1.25143

Abstract

The Mojo Village mangrove forest in Pemalang has undergone environmental degradation due to land conversion into shrimp farming areas. This conversion has led to increased anthropogenic activities, which are potential sources of heavy metal contamination in the waters, particularly lead (Pb). This study aimed to analyse Pb concentrations in sediments and gastropods and assess the potential of gastropods as bioindicators of Pb pollution. Sample preparation followed the USEPA 3051 method, and Pb analysis was conducted using Atomic Absorption Spectrophotometry (AAS). The results identified five gastropod species: Littoraria melanostoma, Littoraria scabra, Cerithidea cingulata, Cerithidea obtusa, and Cerithidea decollata. Pb concentrations in sediments averaged 11.86 ± 1.24 mg/kg, while in gastropods, the average was 0.43 ± 0.16 mg/kg. Although Pb levels in sediments indicate low contamination and no pollution, they may still pose potential biological risks. Cerithidea cingulata and Cerithidea obtusa were categorized as deco-concentrators with the potential to serve as bioindicators of Pb pollution. The study also revealed a very strong correlation between Pb concentrations in sediments and gastropods.
Spatial Distribution and Gastropod Associations Based on Tawiri and Tanjung Tiram Mangrove Habitat in Ambon, Maluku, Indonesia Simatupang, Candida Putri Nauli; Bengen, Dietriech G.; Retraubun, Alex S.W.; Ismet, Meutia Samira; Abrahamsz, Jodie G.
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i1.23812

Abstract

Ambon Island is an area that has the potential for a mangrove ecosystem. Ambon Island has a unique bay covered with mangroves. When viewed from the topography, Ambon Bay is divided into Outer Ambon Bay and Inner Ambon Bay, which are separated by a narrow and shallow threshold. Tawiri has five species of mangroves, and Tanjung Tiram has three species of mangroves.  The density of mangroves as the main constituent of the ecosystem greatly influences the existence of associated biota, namely gastropods themselves. Gastropods have an important role in the food chain cycle in the mangrove ecosystem. This research was conducted in August–September 2023 in the Tawiri (Outer Ambon Bay) and Tanjung Tiram (Inner Ambon Bay) mangrove areas. Data collection for gastropods and mangrove ecosystems used quadrat transects, while for organic materials they used sediment cores. The association between gastropods and mangroves was analyzed using correspondence analysis (CA). The research results show that Tawiri has seven families and 10 species of gastropods. Tanjung Tiram has 3 families and 5 species of gastropods. Gastropod species at both study locations were divided into three different size classes for each location. Gastropods at each research location were found to be closely associated with mangroves because mangroves provide sufficient food sources for gastropod life. The results of this research can be useful for providing the latest data regarding the distribution of gastropods and mangroves in Tawiri and Tanjung Tiram.
Status Pencemaran Lingkungan Akibat Sampah Laut pada Ekosistem Pantai di Purworejo Mutaqin, Bachtiar W.; Yuniasari, Fianika; Septian, Bambang; Kusumawati, Meir Diana; Nuzula, Affie Maghfira; Monica, Inneke; Purnama, Ig. L. Setyawan; Harini, Rika
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i1.24974

Abstract

Marine debris that is found in the coastal ecosystem on the coast of Purworejo can cause pollution and environmental degradation and will result in changes, both spatially and socio-economically. Until now, there has been no research that discusses the environmental status of the coastal ecosystem on the coast of Purworejo in relation to marine debris. Therefore, the goal of this study is to assess the level of environmental pollution in Purworejo's coastal ecosystem as a result of marine debris, particularly along the coast of Purwodadi. An interdisciplinary approach using the integrated method of field surveys and laboratory analysis will be used to achieve the research objectives. Marine debris sampling was carried out using belt transects on all visible debris. After sorting marine debris by type, the Clean Coast Index (CCI) and the Hazardous Item Index (HII) were calculated. At least 9 types of marine debris were found at the study location, namely plastic, plastic foam, glass and ceramics, cloth, foam, rubber, paper, metal, and other materials. At Jatikontal Beach, the CCI and HII values were greater in the backshore zone, reaching 144 (CCI - very dirty) and Class IV (lots of hazardous marine debris found). Meanwhile, at the Demang Gedi Mangrove Education Park, the largest CCI and HII values, namely 18.33 (dirty) and 1.60 (Class III—large amounts of hazardous marine debris found), were found in the plot with the seedling zone. The CCI and HII values can be used to assess the status of environmental pollution in the coastal ecosystem on the coast of Purwodadi, Purworejo Regency, as well as a basis for develop coastal area management policies.  Sampah laut yang terdapat pada ekosistem pantai di kepesisiran Purworejo dapat mengakibatkan pencemaran, penurunan kualitas lingkungan, dan akan mengakibatkan perubahan, baik secara spasial dan sosial-ekonomi. Hingga saat ini, belum ada penelitian yang membahas terkait status lingkungan pada ekosistem pantai di kepesisiran Purworejo kaitannya dengan sampah laut. Oleh karena itu, penelitian ini bertujuan untuk menganalisis status pencemaran lingkungan pada ekosistem pantai yang disebabkan oleh sampah laut di Purworejo, khususnya di kepesisiran Purwodadi. Pendekatan interdisipliner dengan menggunakan metode integrasi survei lapangan dan analisis laboratorium akan digunakan untuk mencapai tujuan penelitian. Pengambilan sampel sampah laut dilakukan menggunakan transek sabuk terhadap semua sampah yang visible atau terlihat. Setelah memilah sampah laut berdasarkan jenisnya, kemudian dilakukan penghitungan indeks kebersihan pantai (Clean Coast Index/CCI) dan indeks barang berbahaya (Hazardous Item Index/HII). Di lokasi kajian ditemukan setidaknya 9 jenis sampah, yaitu plastik, busa plastik, kaca dan keramik, kain, busa, karet, kertas, logam, dan bahan lainnya. Di Pantai Jatikontal, nilai CCI dan HII semakin besar pada zona belakang pantai (backshore), yaitu mencapai 144 (CCI - sangat kotor) dan Kelas IV (ditemukan banyak sampah yang berbahaya). Sedangkan pada Taman Edukasi Mangrove Demang Gedi, nilai CCI dan HII terbesar, yaitu 18,33 (kotor) dan 1,60 (Kelas III - sejumlah besar sampah berbahaya ditemukan), terdapat pada plot dengan zona anakan. Nilai CCI dan HII tersebut dapat digunakan untuk menilai status pencemaran lingkungan pada ekosistem pantai di kepesisiran Purwodadi, Kabupaten Purworejo, sekaligus sebagai dasar dalam pengambilan kebijakan pengelolaan wilayah kepesisiran. 
Molecular Characterization of Microalgae Thalassiosira sp. Based on Genetic Marker tufA and Potential Test for Bioremediation of Heavy Metal Lead (Pb) Izzudin, Maulana Zidan; Kusumaningrum, Hermin Pancasakti; Zainuri, Muhammad; Nurhayati, Nurhayati; Jannah, Siti Nur; Wahyuningsih, Candra; Herida, Azalia Puspa; Doktorasaintifika, Heradita Kaniaazzahra
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i1.25463

Abstract

Heavy metal lead (Pb) pollution in aquatic environments poses a serious threat to aquatic ecosystems and human health. The microalga Thalassiosira  sp. has potential as a bioremediation agent for heavy metals; however, further studies are needed to maximize its capability. This study aims to molecularly characterize Thalassiosira  sp. using the tufA gene, evaluate the effects of Pb on growth and cell morphology, and assess its Pb uptake efficiency. Methods included DNA isolation, phylogenetic analysis, growth measurement using a hemocytometer, Pb uptake testing via ICP-OES, and cell morphology analysis. Results showed that the tufA gene could molecularly characterize Thalassiosira  sp., with a phylogenetic similarity of 99.53% to Conticriba weissflogii (MH571875.1). Pb significantly inhibited growth at concentrations of 0.03 ppm and 0.05 ppm and caused cell aggregation and pigment degradation at higher concentrations (2 ppm). This microalga exhibited the highest Pb uptake efficiency at lower concentrations (0.03–0.05 ppm), reaching 100%, while at 2 ppm, the efficiency decreased to 40%. This study highlights the potential of Thalassiosira  sp. in remediating Pb, providing a foundation for the development of microalgae-based biotechnological applications.
The Characteristics of Bioplastic Made from Sodium Alginate and Kappa Carrageenan Putri, Dhiya Aflah Luswanto; Ridlo, Ali; Hartati, Retno
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i1.25887

Abstract

Synthetic plastic is commonly used daily, but its non-biodegradable nature poses a significant environmental threat. Therefore, it is urgent to explore sustainable alternatives such as bioplastics. Alginate, a polysaccharide, is a promising raw material for bioplastics. However, its poor elasticity characteristic necessitates the addition of other polysaccharides, such as carrageenan, to improve bioplastics' mechanical properties. This research aims to determine the characteristics (physical and mechanical properties) of bioplastics made from a mixture of alginate and kappa-carrageenan. The laboratory experimental methods were applied with a completely randomized design. The treatments are mixtures of alginate and k-carrageenan in the following ratios: 10:0 (A10K0), 8:2 (A8K2), 6:4 (A6K4), 4:6 (A4K6), 2:8 (A2K8), 0:10 (A0K10). The characteristics of bioplastic films measured were thickness, water resistance, tensile strength, elongation, and appearance. The optimal bioplastic formulation (4:6 ratio of k-carrageenan to alginate) exhibited a film thickness of 138.3 µm, 16.6% biodegradability, tensile strength of 22.965 N/mm², and 2.73% elongation. The scanning electron microscope showed that the surface structure of bioplastic A4K6 made fromthe ratios of k-carrageenan and alginate of 4:6 had fewer structure cracks and more surface smoothness. 
Dinamika Suhu Permukaan Laut dan Konsentrasi Klorofil-a di Perairan Laut Flores Hubungannya dengan Fenomena ENSO dan IOD Rachman, Herlambang Aulia; Hidayah, Zainul; Yuliardi, Amir Yarkhasy
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i1.25779

Abstract

The Flores Sea is a central region of Indonesia that plays a crucial role in the circulation of water masses. This area serves as a key pathway for the Indonesian Throughflow (ITF), which transports water from the Pacific to the Indian Ocean. The region is also known for its high productivity, particularly in fisheries. This study analyzes two important oceanographic parameters: Sea Surface Temperature (SST) and Chlorophyll-a concentration. The analyses conducted include monthly averages and anomalies and their relationship with interannual phenomena such as the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). To quantify the relationship between oceanographic parameters and these phenomena, correlation and partial correlation analyses were performed. The results indicate that SST and Chlorophyll-a exhibit seasonal fluctuations, particularly in the northern Flores Sea near Sulawesi Island. These fluctuations are suspected to be caused by seasonal upwelling in the region, driven by the movement of the Southeast Monsoon winds during the East Monsoon season (June–August). Upwelling is concentrated in the northern part of the Flores Sea, along the southern coast of Sulawesi Island. The correlation and partial correlation analyses also show that ENSO and IOD significantly impact the variability of oceanographic parameters in the Flores Sea, with IOD exerting a stronger influence than ENSO. Perairan Laut Flores merupakan kawasan yang terletak pada bagian sentral wilayah Indonesia yang memiliki peranan penting dalam sirkulasi massa air di Indonesia. Wilayah ini merupakan lokasi aliran Arus Lintas Indonesia (Arlindo) atau Indonesian Throughflow (ITF) yang mengalir dari Samudera Pasific menuju Hindia. Wilayah ini juga dikenal memiliki produktifitas perikanan yang cukup tinggi khususnya dalam sektor perikanan. Dalam penelitian ini menganalisis bagaimana dua parameter oseanografi yang cukup penting yakni Suhu Permukaan Laut (SPL) dan Konsentrasi Klorofil-a. Analisis yang dilakukan antara lain adalah rata-rata bulanan, anomaly, dan hubungannya dengan fenomena antar tahunan seperti El Nino Southern Oscillation (ENSO) dan Indian Ocean Dipole (IOD). Untuk mengkuantifikasi hubungan antara parameter oseanografi dengan kedua fenomena tersebut maka dilakukan analisis korelasi dan partsial korelasi. Hasilnya adalah parameter SPL dan Klorofil-a memiliki fluktuasi secara musiman, khususnya yang berada pada sisi utara dekat Pulau Sulawesi. Fluktuasi ini diduga diakibatkan oleh adanya fenomena Upwelling yang terjadi secara musiman pada wilayah ini akibat pergerakan dari Angin Muson Tenggara pada musim Timur (Juni-Agustus). Upwelling terfokus pada wilayah bagian sisi utara Laut Flores (pesisir selatan Pulau Sulawesi). Hasil analisis korelasi dan parsial korelasi juga menunjukkan fenomena ENSO dan IOD memberikan pengaruh yang cukup tinggi terhadap variabilitas parameter oseanografi di Laut Flores. Dimana fenomena IOD memberikan dampak yang lebih kuat dibanding dengan fenomena ENSO. 
Variasi Musiman Suhu Dan Klorofil-a Serta Hubungan dengan Hasil Tangkapan Ikan Kembung (Rastrelliger sp.) Laut Natuna Hanafi, Hanafi; Aprinsyah, Apriansyah; Safitri, Ikha
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/baf.%v.%i.%Y.%p

Abstract

The Natuna Sea, renowned for its abundant fishery resources, serves as a primary destination for both local and international fishermen. This study focuses on examining the seasonal variations in sea surface temperature (SST) and chlorophyll-a concentrations, as well as their correlations with the catch rates of mackerel (Rastrelliger sp.). Employing climatological analysis, Catch Per Unit Effort (CPUE), and correlation techniques, this research utilizes satellite imagery data from the Marine Copernicus program for chlorophyll-a and SST, alongside catch data obtained from the Pemangkat Fish Landing Port using purse seine and gillnet methods. The findings indicate significant fluctuations in chlorophyll-a and SST that influence the productivity of mackerel catch, with chlorophyll-a levels ranging from 0.40 to 0.69 mg/m³ and an average of 0.37 mg/m³, while SST varies from 27 to 30 °C, averaging 29.11 °C. The peak catch period occurs during the transition seasons I (May) and II (July), providing valuable insights for optimizing capture strategies and serving as a guide for further research on the environmental impacts affecting catch rates.  Laut Natuna, yang dikenal karena sumber daya perikanannya yang melimpah, merupakan destinasi utama bagi nelayan lokal dan internasional. Penelitian ini berfokus pada pemeriksaan variasi musiman suhu permukaan laut (SPL) dan konsentrasi klorofil-a serta korelasinya dengan tingkat tangkapan Ikan Kembung (Rastrelliger sp.). dengan menggunakan analisis klimatologi, Catch Per Unit effort (CPUE), dan teknik korelasi, penelitian ini memanfaatkan data citra satelit Marine Copernicus untuk klorofil-a dan SPL, serta data tangkapan dari Pelabuhan Pendaratan Ikan Pemangkat yang diperoleh melalui metode jaring pukat cincin dan jaring insang. Hasil penelitian ini menunjukkan fluktuasi signifikan dalam klorofil-a dan SPL yang mempengaruhi produktivitas hasil tangkapan Ikan Kembung, dengan tingkat klorofil-a berkisar antara 0,40 hingga 0, 69 mg/m³ dan rata-rata 0,37 mg/m3, sementara SPL bervariasi antara 27 hingga 30 oC., dengan rata-rata 29,11 oC. Periode puncak tangkapan terjadi pada musim peralihan I (Mei) dan II (Juli), memberikan wawasan berharga untuk mengoptimalkan strategi penangkapan dan sebagai panduan untuk penelitian lebih lanjut mengenai pengaruh lingkungan terhadap tingkat tangkapan. 
Species Diversity of Fiddler Crabs (Uca spp.) in the Mangrove Ecosystem of Duta Coastal, Probolinggo Regency, East Java Setiawan, Rendy; Anjani, Rifkah Ajeng; Fajariyah, Susantin; Cahyono, Haris; Kurniawan, Joko
Jurnal Kelautan Tropis Vol 28, No 1 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i1.24299

Abstract

Fiddler crab (Uca spp.) belongs to the Order Decapoda and Family Ocypodidae, which live by making burrows in the substrate between mangrove plants. The presence of fiddler crabs plays an important role in mangrove ecosystems, which can increase sediment mineralisation due to burrows that can increase oxygen distribution into the sediment. This research was conducted in the mangrove ecosystem of Duta coastal, Probolinggo Regency. The method used when sampling biota in this study is the transect-plot method, which is used to place 1x1 m2 plots systematically along the transect. Sampling of fiddler crabs was carried out at the lowest low tide. Samples taken were fiddler crabs in the plot. Data on the species found, the number of individuals of each species, and the total number of individuals obtained from species composition were used to calculate species diversity. Fiddler crabs (Uca spp.) found in the mangrove ecosystem Duta coastal were 10 species, namely U. perplexa, U. rosea, U. vocans, U. annulipes, U. triangularis, U. coarctata, U. tetragonon, U. vomeris, U. forcipata, and U. dussumieri. The diversity value of fiddler crab species in the Ambassador Coastal Mangrove ecosystem is moderate (Hˈ = 2.209). All species of fiddler crabs were found in the muddy sand substrate type, because the burrow structure is strong, so that when the tide, the burrow condition is maintained.