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Jurnal Kelautan Tropis
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Articles 451 Documents
Estimasi Pengukuran Panjang Udang Litopenaeus Vannamei Menggunakan Algoritma Yolov8 Dan Perhitungan Jarak Euclidean Adriono, Erwin; Auliya, Novita; Septiana, Risma
Jurnal Kelautan Tropis Vol 27, No 3 (2024): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v27i3.24528

Abstract

Cultivation of Litopenaeus vannamei shrimp is an important fishery commodity in Indonesia. Providing the right amount of feed is crucial for optimal shrimp growth. The amount of feed given greatly depends on the measurement of shrimp length. The aim of this research is to develop an image processing-based program for measuring the length of Litopenaeus vannamei shrimp using the YOLOv8 algorithm through Euclidean distance calculation. YOLOv8 detects shrimp objects within a defined distance. The obtained images are used to estimate the length using Euclidean distance calculation. The results show that this program can detect and measure shrimp length with an accuracy of 96.8%. Based on the detected shrimp length, the program can calculate the Mean Body Weight (MBW) and Feeding Ratio (FR) with an average error below 5%.  Budidaya udang Litopenaeus Vannamei merupakan komoditas perikanan yang penting di Indonesia. Pemberian pakan yang tepat jumlah sangat penting untuk pertumbuhan udang yang optimal. Jumlah pemberian pakan sangat bergantung pada pengukuran panjang udang. Tujuan penelitian ini adalah mengembangkan sebuah program berbasis pengolahan citra panjang udang Litopenaeus Vannamei dengan algoritma YOLOv8 melalui perhitungan jarak euclidean. YOLOv8 melakukan deteksi terhadap objek udang yang sudah dibatasi jarak. Gambar yang diperoleh akan dihitung estimasi panjangnya menggunakan perhitungan jarak euclidean. Hasil penelitian menunjukkan program ini dapat mendeteksi dan mengukur panjang udang dengan akurasi 96,8%. Berdasarkan panjang udang yang terdeteksi, program dapat menghitung nilai MBW (Mean Body Weight) dan FR (Feeding Ratio) dengan error rata-rata di bawah 5%.
Perkembangan Diatom Perifiton Pada Substrat Buatan di Perairan Pulau Panjang, Jepara Syauqina Nashihi Aufar; Agus Sabdono; Diah Permata Wijayanti; Munasik Munasik
Jurnal Kelautan Tropis Vol 26, No 3 (2023): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v26i3.19779

Abstract

Degradation of marine waters in Panjang Island is increasing resulting in high production of benthic periphyton. Procurement of hard substrate as material for artificial reefs is one of the efforts to see the succession pattern of benthic periphyton microscopically. The purpose of this study was to determine the differences in the abundance and composition of diatoms in geopolymer concrete and ordinary concrete substrates. The method used is the field experimental method, immersing different concrete substrates, namely geopolymer concrete (BA) and ordinary concrete (BT) in the sea waters of Panjang Island at a depth of 3 m for 2 months. Periphyton growth on the substrate was observed microscopically using the Scanning Electronic Microscope (SEM) method. Observations were made at immersion time of 1 day (T1), 7 days (T2), 14 days (T3), 28 days (T4), and 56 days (T5). The results showed that there were differences in the development of Periphyton Diatoms between geopolymer (BA) and ordinary concrete (BT) substrates. On both substrates, periphyton growth was found starting from the observation of soaking for 1 day. The density and diversity of periphyton on the BA substrate was higher than that of the BT substrate, with a density of 2535 cell cm-2 and 73 cell cm-2, respectively, and the diversity of H'Shanon Wiener was 4.07 and 0.33. The benefit of this research is to determine the initial succession of biofilm formation on artificial substrates as a building material for artificial reefs for coral reef restoration programs, especially in marginal reef conditions.  Degradasi perairan laut di Pulau Panjang semakin meningkat mengakibatkan produksi perifiton bentik yang tinggi. Pengadaan substrat keras sebagai bahan terumbu buatan menjadi salah satu upaya untuk melihat pola suksesi perifiton bentik secara mikroskopis.  Tujuan dilakukannya penelitian ini untuk mengetahui perbedaan kelimpahan dan komposisi diatom pada substrat beton geopolimer dan beton biasa. Metode yang digunakan yaitu metode eksperimental lapangan, dilakukan perendaman substrat beton yang berbeda yaitu beton geopolymer (BA) dan beton biasa (BT) di perairan laut pulau Panjangdi pada kedalaman 3 m selama 2 bulan. Pertumbuhan perifiton pada substrat diamati secara mikroskopis menggunakan metode Scanning Electronic Microscope (SEM).  Pengamatan dilakukan pada lama perendaman 1 hari (T1), 7hari (T2), 14 hari (T3), 28 hari (T4), dan 56 hari (T5). Hasil penelitian menunjukkan ada perbedaan Perkembangan Diatom Perifiton antara substrat geopolymer (BA) dan beton biasa (BT). Pada ke dua substrat dijumpai pertumbuhan perifiton mulai pengamatan perendaman selama 1 hari. Densitas dan keragaman perifiton pada substrat BA lebih tinggi daripada substrat BT yaitu masing-masing dengan densitas 2535 sel cm-2 dan 73 sel cm-2, dan keragaman H’Shanon Wiener  sebesar 4,07 dan 0,33. Manfaat dari penelitian ini adalah untuk mengetahui suksesi awal pembentukan biofilm pada substrat buatan sebagai bahan penyusun terumbu buatan untuk program restorasi terumbu karang khususnya pada kondisi terumbu marginal.
Effects of seasonal variation on the characteristics of stranded marine debris within Rambut Island Wildlife Reserve, Indonesia Rahman, Lucky; Zamani, Neviaty Putri; Ismet, Meutia Samira; Cordova, Muhammad Reza
Jurnal Kelautan Tropis Vol 27, No 1 (2024): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v27i1.20655

Abstract

Monitoring and assessing the items stranded on shorelines is a crucial step in addressing the threat posed by marine debris to our ocean. The objective of this study is to examine the occurrence and categorize marine debris that accumulates on the beach and mangrove area of Pulau Rambut Wildlife Reserve from the transitional season 2 to the rainy season. The abundance of marine debris is significant in transitional season 2. There is no significant difference between different seasons. The dominant form of debris among all macrodebris categories during transitional season 2 was plastic, accounting for 46.38% of the total. Single-use plastics like styrofoam, shoes, sandals, gloves, plastic wrap, and plastic sachets were found to be the most common types of large-scale plastic debris, comprising 60% of total macroplastic debris. The debris found on Rambut Island is believed to originate from debris carried by rivers that flow into Jakarta Bay. The presence of seasonal winds, currents, waves, and tides further contribute to the accumulation of debris in this area.
Identifikasi Spesies Mangrove dengan menggunakan Metode Principal Component Analysis (PCA) pada Citra Landsat-8 di Taman Nasional Sembilang, Sumatera Selatan, Indonesia Ginting, Devica Natalia Br; Faristyawan, Rizky; Safitri, Siti Nurulita Mutiara; Winarso, Gathot
Jurnal Kelautan Tropis Vol 27, No 2 (2024): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v27i2.22830

Abstract

Mangroves are coastal plants influenced by tidal cycles. One of the regions in South Sumatra Province with a mangrove ecosystem is Sembilang National Park. As a national park, this location is strategically positioned for research related to mangrove species. The utilization of the Principal Component Analysis (PCA) method is considered to enhance the capabilities of remote sensing data in mangrove mapping. However, its application has been limited to the mangrove level. The research objective is to identify mangrove species in Sembilang National Park using the PCA method by leveraging Landsat-8 image data acquired on September 9, 2019. Mangrove distribution is obtained through the Mangrove Vegetation Index (MVI) and vector data from Global Mangrove Watch. The image is then overlaid with field species data to obtain species spectral patterns. Additionally, the correlation between spectral band values and eigenvalues (PC) is analyzed to detect parameters correlated with eigenvalues. The research results show that PC values correlate with mangrove species and can be used for mangrove species identification. This is demonstrated by Bruguiera Gymnorrhiza species with canopy coverage of 60.8% and 62.46% at ST7 and ST8 having the same PC values, while mangroves with canopy coverage of 62.5% in different species have different PC values. Moreover, the PCA method can indicate two crucial factors in identifying mangrove species, namely vegetation and soil factors.  Mangrove merupakan tumbuhan pesisir yang dipengaruhi oleh pasang surut. Salah satu wilayah di Provinsi Sumatera Selatan yang memiliki ekosistem mangrove adalah Taman Nasional Sembilang. Sebagai taman nasional, lokasi ini sangat strategis untuk dilakukan penelitian terkait spesies mangrove. Pemanfaatan metode principal component analysis (PCA) dinilai mampu meningkatkan kemampuan data penginderaan jauh dalam pemetaan mangrove. Namun selama ini, pemanfaatan terbatas pada level mangrove. Adapun tujuan penelitian adalah mengidentifikasi spesies mangrove di Taman Nasional Sembilang menggunakan metode PCA dengan memanfaatkan data citra Landsat-8 yang diakusisi pada 09 September 2019. Sebaran mangrove diperoleh melalui indeks vegetasi mangrove (MVI) dan data vektor dari Global Mangrove Watch. Citra tersebut kemudian di overlay dengan data spesies lapangan untuk mendapatkan pola spektral species. Selain itu, korelasi nilai spektral band dan eigen (PC) dianalisis untuk mendeteksi parameter yang berkorelasi dengan nilai eigen. Hasil penelitian menunjukkan nilai PC memiliki korelasi dengan spesies mangrove dan dapat digunakan untuk mengidentifikasi spesies mangrove. Hal ini ditunjukkan spesies Bruguiera Gymnorrhiza dengan tutupan kanopi 60,8% dan 62,46% pada ST7 dan ST8 memiliki nilai PC yang sama serta mangrove dengan besaran tutupan kanopi 62,5% pada spesies nilai PC berbeda. Selain itu, metode PCA mampu menunjukkan dua faktor penting dalam mengidentifikasi spesies mangrove, yaitu faktor vegetasi dan tanah.
Growth of Gracilaria sp. in Monoculture and Polyculture System with Milkfish (Chanos chanos Forsk) in Traditional Ponds, Brebes Regency, Central Java Rahmawati, Vira Rizqi; Rejeki, Sri; Amalia, Rosa; Widowati, Lestari Lakhsmi; Ariyati, Restiana Wisnu; Nauta, Reinier; Lansbergen, Romi
Jurnal Kelautan Tropis Vol 27, No 1 (2024): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v27i1.22236

Abstract

Gracilaria sp. has a high economic value, which can be cultivated in monoculture or polyculture with other cultivars, such as milkfish (Chanos chanos Forsk). Polyculture of Gracilaria sp. with milkfish can increase the growth of Gracilaria sp. because the metabolic products of milkfish are helpful as a source of nutrients for Gracilaria sp. This study aimed to (1) examine the effect of Gracilaria sp. cultivation in monoculture and polyculture with milkfish on the growth of Gracilaria sp. and (2) the nutrient content of the water. This study used an experimental method with two treatments and three replications using six (6) earth ponds: Gracilaria sp. monoculture and polyculture with milkfish. Growth and nutrient content (nitrate and phosphate) data were analyzed using a t-test. The results of the study showed that the growth of Gracilaria sp. polyculture with milkfish provided absolute growth of 3615.89 ± 330.84 g; Relative Growth Rate (RGR) 180.79 ± 16.54 %; and Specific Growth Rate (SGR) 2.29 ± 0.13 %/day were significantly higher, compared with the growth of Gracilaria sp. monoculture. Monoculture Gracilaria sp showed absolute growth of 1912.71 ± 386.94 g; RGR 95.64 ± 19.35 %; and SGR 1.48 ± 0.22 %.day-1. Nutrient content in polyculture pond waters revealed nitrate 1.08 ± 0.09 mg.L-1 and phosphate 0.18 ± 0.04 mg.L-1 were significantly higher compared to nutrient content in monoculture pond waters which were nitrate 0.71 ± 0.22 mg.L-1 and 0.07 ± 0.04 mg.L-1. Polyculture Gracilaria and seaweed provide higher production due to the enrichment from nutrient content. 
Ketidakseragaman Sebaran Spasial Variabilitas Musiman Eddy di Perairan Barat Laut Indonesia Kartadikaria, Aditya Rakhmat; Napitupulu, Gandhi; Rangga, Kalaka; Radjawane, Ivonne Milichristi; Abdullah, Faizal Ade Rahmahuddin
Jurnal Kelautan Tropis Vol 27, No 1 (2024): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v27i1.20810

Abstract

Sea level anomaly (SLA) data spanning from 1993 – 2022 were used to analyze the characteristic of eddy current in Northwest Indonesian. An improved winding angle method was used and was able to detect 1663 anticyclonic eddies (AEs) and 1748 cyclonic eddies (CEs). The average eddy lifespan is approximately four weeks. The eddy in the West Indonesian Ocean has a radius ranging from 40 – 100 km and a high number of mesoscale eddy (radius more than 100 km) detected in the northern area of West Indonesian Ocean (4° N - 10° N). The eddy kinetic energy (EKE) increased proportionally with their radius, whereas the eddy vorticity decreased proportionally with their increasing radius. The seasonal cycles of eddy circulation in the west Indonesian Ocean were differ for both AEs and CEs, where AEs were dominated during east monsoon season (JJA) and CEs came with longer periods from November to March, yet for both AEs and CEs they have similar radius per month. During weak periods of both eddies, their meridional distributions differ; CEs tend to be formed in relatively lower latitude, while AEs were concentrated in relatively higher latitude. Data anomali permukaan laut/sea level anomaly (SLA) dalam kurun waktu 1993 – 2022 digunakan untuk mempelajari karakteristik sirkulasi arus eddy di perairan barat laut Indonesia. Metode Winding Angles yang telah dimodifikasi mampu mendeteksi 1663 anticyclonic eddies (AE) dan 1748  cyclonic eddies (CE). Rata-rata umur eddy yang terdeteksi adalah sekitar empat minggu. Mayoritas sirkulasi arus eddy memiliki radius 40 – 100 km dan eddy dengan radius berskala meso (lebih dari 100 km) banyak terkonsentrasi di bagian utara (4° N - 10° N) perairan barat laut Indonesia. Nilai energi kinetik eddy (EKE) bertambah sebanding dengan pertambahan radius, sedangkan nilai vortisitas berbanding terbalik dengan radius. Sirkulasi arus eddy di perairan barat laut Indonesia pada musim timur (JJA) didominasi oleh AE , sedangkan CE mendominasi di musim barat (DJF) dengan periode yang lebih panjang dari November hingga Maret, namun dengan rata-rata radius yang sama setiap bulannya. Pada saat periode di mana kejadian eddy minimum, ditemukan perbedaan letak distribusi meridional eddy bervortisitas tinggi yang menunjukkan CE lebih didukung pembentukannya pada lintang yang lebih rendah daripada AE. 
Total Suspended Solids in Teluk Awur, Jepara using Red Reflectance from Landsat-8 Andhita, Laviola Reycha Fitri; Maslukah, Lilik; Wirasatriya, Anindya; Indrayanti, Elis; Prasetyawan, Indra Budi
Jurnal Kelautan Tropis Vol 27, No 3 (2024): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v27i3.23717

Abstract

The coastal waters of Teluk Awur, Jepara are affected by human activities such as aquaculture, tourism, agriculture, and settlements. The number of human activities on land will contribute to high suspended solids (TSS) entering coastal waters by run-off. The high TSS in coastal areas will affect the entry of light intensity, disrupting the photosynthesis process and ecosystem. This study compares TSS values based on Landsat images using several TSS algorithms such as Wirasatriya, Budhiman, Ajiperwata, and Parwati algorithms and the algorithm resulting from the July 2023 field data calibration against red reflectance. The algorithm's performance from calibration has a smaller error value with RMSE = 8.51, MAPE = 25.77%, and Bias = 7.52. TSS estimation from Landsat 8 satellite imagery has a range of values of 30.56 - 62.55 mg/L (average 35.60 mg/L), while field measurements of TSS values are 22.40 - 64.52 mg/L (average 32.69 mg/L). This research will be valuable information for using the right Landsat-8 algorithm for temporal and sustainable TSS monitoring. It can be used in abrasion monitoring and management in the Teluk Awur coastal waters of Jepara.
Preparasi dan Karakterisasi Bioplastik dari Limbah Ekstraksi Karagenan Rumput Laut Kappaphycus alvarezii (Doty) Doty ex P. C. Silva, 1966 dengan Pemlastis Gliserol Ridlo, Ali; Sabdono, Agus; Subagiyo, Subagiyo; Ario, Raden; Pratikto, Ibnu; Hartati, Retno
Jurnal Kelautan Tropis Vol 27, No 3 (2024): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v27i3.24061

Abstract

The carrageenan production process from Kappaphycus alvarezii seaweed produces solid waste of 60%-70% w/w, primarily composed of cellulose, which can be used for bioplastic films. This research aims to determine the effect of glycerol plasticizer addition on the characteristics of K. alvarezii waste-based bioplastics. Bioplastics were made by mixing 50 g of wet waste with 90 mL of distilled water, homogenized at 70°C for 30 minutes. Glycerol (0%, 1%, 2%, 3%, 4%) was added, with water to a total volume of 150 mL, and homogenized again for 30 minutes. The solution was poured into a polypropylene mold and dried at 60°C for 24 hours. Results showed glycerol increased transparency and elongation but reduced tensile strength and water resistance. The addition of 1% glycerol produced bioplastics with the best characteristics, meeting Japanese Industrial Standards. FTIR and SEM showed similar bioplastic properties across treatments. This research indicates that K. alvarezii carrageenan extraction waste is promising for packaging material and bioplastic production.  Proses produksi karagenan dari rumput laut Kappaphycus alvarezii menghasilkan limbah padat sebesar 60%-70% w/w, terutama terdiri dari selulosa yang dapat digunakan untuk film bioplastik. Penelitian ini bertujuan untuk mengetahui pengaruh penambahan plastisizer gliserol terhadap karakteristik bioplastik limbah K. alvarezii. Bioplastik dibuat dengan mencampurkan 50 g limbah basah dengan 90 mL akuades, dihomogenkan pada suhu 70°C selama 30 menit. Gliserol (0%, 1%, 2%, 3%, 4%) ditambahkan hingga volume 150 mL, dihomogenkan kembali selama 30 menit. Larutan dituang dalam cetakan polipropilena dan dikeringkan pada suhu 60°C selama 24 jam. Hasil penelitian menunjukkan gliserol meningkatkan transparansi dan elongasi, tetapi mengurangi kuat tarik dan ketahanan air. Penambahan 1% gliserol menghasilkan bioplastik dengan karakteristik terbaik, memenuhi Japanese Industrial Standard. FTIR dan SEM menunjukkan sifat bioplastik yang serupa pada semua perlakuan. Penelitian ini menunjukkan bahwa limbah ekstraksi karagenan K. alvarezii menjanjikan sebagai bahan kemasan dan produksi bioplastik.
Temporal Analysis of Mangrove Canopy Cover of High Resolution Satellite Imagery on the West Coast of Bangkalan Regency, Madura East Java Hanifa, Siti Nur; Rachman, Herlambang Aulia; Hidayah, Zainul
Jurnal Kelautan Tropis Vol 27, No 3 (2024): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v27i3.24273

Abstract

Mangroves are plants that live in muddy substrates, muddy sand, sand to tidal areas. These plants have important roles for marine organisms, carbon sequestration, as shoreline protectors from waves or erosion and sediment filters before entering the sea. The influence of human activity in the form of conversion of mangrove land to other forms or caused by natural disasters is a dangerous threat to the mangrove ecosystem. The magnitude of mangrove cover change is an important component so information is needed on changes in the spatial and temporal distribution of mangrove cover. This study aims to temporally analyze mangrove cover using high-resolution satellite imagery on the West Coast of Bangkalan Regency. This research uses secondary data in the form of Planetscope high-resolution satellite images from 2018 - 2023. The data will be processed to determine changes in mangrove area using Fv (Fractional Vegetation Cover). Calculation of the Fv (Fractional Vegetation Cover) value is done from the results of the minimum and maximum values of NDVI (Normalized Difference Vegetation Index). The results showed that there was a change in mangrove cover which was initially included in the FVC (Full Vegetation Coverage) class in 2022 with an area of 41.12 Ha to the HVC (High Vegetation Coverage) class with an area of 84.82 Ha in 2020. At the Arosbaya location, the highest Fv value occurred in 2019 with an area of 206.48 Ha. Reduction of mangrove area occurred in Sepulu and Arosbaya sub-districts due to land use change and sedimentation.
Wave Characteristics in the Northern Waters of Central Java Based on the Wavewatch III Numerical Model Efendi, Usman; Ismanto, Aris; Rochaddi, Baskoro; Putra, Sebrian Mirdeklis Beselly
Jurnal Kelautan Tropis Vol 27, No 3 (2024): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v27i3.24850

Abstract

The northern coast of Central Java is a strategic development area, but it has the potential for high wave disasters. Planning activities and mitigating maritime disaster risks requires an understanding of wave characteristics. This study analyzes wave characteristics in the northern waters of Central Java using the Wavewatch III numerical model. Significant wave height and wave direction were averaged from 2014 to 2023. The results showed that wave conditions in the northern waters of Central Java tend to be higher in December, January, February, July, August, and September. Meanwhile wave conditions tend to be lower in March, April, May, June, October, and November.