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Pendugaan Daerah Tangkapan Ikan Pelagis Kecil di Perairan Pesisir Utara Jawa Tengah Berdasarkan Paremater Lingkungan Laut Sarwati, Dhea Erika; Suryono, Chrisna Adhi; Suryono, Suryono
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.v28i1.26262

The North Coast of Central Java is one of the potential areas for small pelagic fisheries. Estimation of fishing areas can be facilitated by utilizing geographic information technology (GIS) in determining potential fishing areas. This study aims to determine potential areas for small pelagic fishing based on sea surface temperature (SST), chlorophyll-a, and current variables. The study was conducted in the North Coast of Central Java using data throughout 2023. This study uses spatial modeling techniques. Sea surface temperature (SST) and chlorophyll-a were obtained from Aqua MODIS imagery, while current data was obtained from AVISO. Catch data is secondary data obtained from the Pekalongan Nusantara Fisheries Port. The results of the study showed that the average value of sea surface temperature ranged from 28.34-30.73⁰C, the value of chlorophyll-a concentration ranged from 0.33-0.76 mg/m³, and the current speed ranged from 0.14-0.28 m/s indicating that sea surface temperature (SST), chlorophyll-a, and currents affect the determination of small pelagic fish catch areas. The regression correlation analysis showed a positive regression correlation result for sea surface temperature and fish catches, conversely chlorophyll-a and current speed were negatively correlated with small pelagic fish catches. The potential areas for small pelagic fishing in the North Waters of Central Java in 2023 showed a varied distribution in each season. The area with the highest frequency of distribution of small pelagic fishing areas occurred in the transition season I, while the East season showed fewer fishing areas. Perairan Pantai Utara Jawa Tengah merupakan salah satu wilayah potensi perikanan tangkap ikan pelagis kecil. Pendugaan daerah penangkapan ikan dapat dipermudah dengan memanfaatkan teknologi informasi geografis (SIG) dalam menentukan daerah penangkapan ikan yang potensial. Penelitian ini bertujuan untuk menentukan daerah potensi penangkapan ikan pelagis kecil berdasarkan variabel suhu permukaan laut (SPL), klorofil-a, dan arus. Penelitian dilakukan di Perairan Pantai Utara Jawa Tengah menggunakan data sepanjang tahun 2023. Penelitian ini menggunakan teknik pemodelan spasial. Suhu permukaan laut (SPL) dan klorofil-a diperoleh dari citra Aqua MODIS, sedangkan data arus diperoleh dari AVISO. Data hasil tangkapan merupakan data sekunder yang diperoleh dari Pelabuhan Perikanan Nusantara Pekalongan. Hasil penelitian menunjukkan bahwa nilai rata-rata suhu permukaan laut berkisar antara 28,34-30,73⁰C, nilai konsentrasi klorofil-a berkisar antara 0,33-0,76 mg/m³, dan kecepatan arus berkisar antara 0,14-0,28 m/s menunjukkan bahwa suhu permukaan laut (SPL), klorofil-a, dan arus berpengaruh terhadap penentuan daerah tangkapan ikan pelagis kecil. Analisis korelasi regresi menunjukkan hasil korelasi regresi positif terhadap suhu permukaan laut dan hasil tangkapan ikan, sebaliknya klorofil-a dan kecepatan arus berkorelasi negatif terhadap hasil tangkapan ikan pelagis kecil. Daerah potensi penangkapan ikan pelagis kecil di Perairan Utara Jawa Tengah pada tahun 2023 menunjukkan distribusi yang variatif di setiap musim. Daerah dengan frekuensi distribusi daerah penangkapan ikan pelagis kecil terbanyak terjadi pada musim peralihan I, sedangkan pada musim Timur menunjukkan daerah tangkapan yang lebih sedikit.

Molecular Identification of Fire Worms in Indonesian Intertidal Waters: The First COI Gene-Based DNA Barcode of Eurythoe complanata Rosyada, Vivian; Buhari, Nurliah; Jefri, Edwin
Jurnal Kelautan Tropis Vol 28, No 2 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i2.26551

Polychaetes, including fireworms, play crucial ecological roles such as nutrient recycling and forming a vital part of the marine food web. However, their accurate identification is challenging due to morphological complexity and the presence of cryptic species. DNA barcoding, particularly targeting the cytochrome oxidase subunit I (COI) gene, has emerged as a powerful tool for species delineation due to its high accuracy and reproducibility. This study aims to molecularly identify fireworm specimens collected from Indonesian intertidal zones using COI gene barcoding. Fireworm samples were collected from Lombok waters, followed by DNA extraction, PCR amplification, electrophoresis, and DNA sequencing. The DNA data were analyzed using MEGA-X software to compare the sequences with those in the database and identify the species. A phylogenetic tree was constructed to illustrate the relationships between the analyzed species. The results show that the fireworm sample from Lombok is classified as Eurythoe complanata, a member of the Amphinomidae family. COI genetic analysis revealed a 658 bp DNA fragment with 77.19% similarity to the same species from India. The phylogenetic tree indicated a close relationship with the Indian species, supported by a bootstrap value of 85. Genetic distances ranged from 0.02 to 0.48, and the dominance of A+T nucleotides suggests the presence of genetic variation.

Sebaran Substrat Dasar Perairan Berdasarkan Nilai Hambur Balik Hidroakustik Di Perairan Sei Enam, Kabupaten Bintan Rohmah, Roseani Baiti; Ma'mun, Asep; Febrianto, Try
Jurnal Kelautan Tropis Vol 28, No 2 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i2.26009

The use of hydroacoustic technology, namely single beam echosounder scientific Simrad EK15 for the measurement of bottom substrate in large area coverage and accurate data. The purpose of this study was to analyze the hydroacoustic backscatter value of bottom substrate, analyze the relationship between the size of the substrate fraction to the backscatter value and map the distribution of bottom substrate in Sei Enam waters, Bintan Regency. This research was conducted on May 29, 2024-December 2024. The results obtained substrate types with a percentage distribution of 46% gravel, 30% sandy gravel, 13% gravelly sand, and 10% slightly gravelly sand. The highest average surface backscattering strength value E1 on gravel ranged from -22.76 dB to -19.84 dB with an average value of E2 ranging from -40.53 dB to -33.34 and the lowest by slightly gravelly sand substrate ranging from -26.63 dB to -25.20 dB with an average value of E2 ranging from -42.54 dB to -29.43 dB. Based on simple linear regression analysis shows the results of a very strong relationship on the size of the diameter fraction with a roughness backscatter value of 0.900 and the size of the diameter fraction of the substrate has an 81,1% influence on the backscatter value, as well as on the size of the diameter fraction has a very strong relationship with hardness of 0.868 and the size of the diameter fraction has an influence of 75.4% on the backscatter value of hardness. In the distribution of substrates from the land direction, the dominant type of gravel substrate and the direction of open water is the type of slightly gravelly sand. Penggunaan teknologi hidroakustik yaitu single beam echosounder scientific Simrad EK15 untuk pengukuran substrat dasar perairan dalam jangkauan area luas dan data akurat. Tujuan penelitian ini adalah untuk menganalisis nilai hambur balik hidroakustik substrat dasar, menganalisis hubungan antara ukuran fraksi substrat terhadap nilai hambur balik dan memetakan sebaran substrat dasar di perairan Sei Enam, Kabupaten Bintan. Penelitian ini dilaksanakan 29 Mei 2024-Desember 2024. Hasil penelitian memperoleh tipe substrat dengan sebaran persentase 46% gravel, 30% sandy gravel, 13% gravelly sand, dan 10% slightly gravelly sand. Nilai surface backscattering strength rata-rata E1 yang tertinggi pada gravel berkisar -22,76 dB sampai -19,84 dB dengan nilai rata-rata E2 berkisar -40,53 dB sampai -33,34 dan terendah oleh substrat slightly gravelly sand berkisar -26,63 dB sampai -25,20 dB dengan nilai rata-rata E2 berkisar -42,54 dB sampai -29,43 dB. Berdasarkan analisis regresi linier sederhana menunjukkan hasil hubungan yang sangat kuat pada ukuran diameter fraksi dengan nilai hambur balik kekasaran sebesar 0,900 dan ukuran diameter fraksi substrat memiliki pengaruh 81,1% terhadap nilai hambur balik, serta pada ukuran diameter fraksi memiliki hubungan yang sangat kuat dengan kekerasan sebesar 0,868 dan ukuran diameter fraksi memiliki pengaruh 75,4% terhadap nilai hambur balik kekerasan. Pada sebaran substrat dari arah daratan dominan tipe substrat gravel dan arah perairan lepas berupa tipe slightly gravelly sand.

Deteksi dan Prediksi Perubahan Garis Pantai Kawasan Pesisir Kelurahan Arung Dalam Menggunakan Citra Satelit Multitemporal Dinnabhan, Fatwa; Pamungkas, Aditya; Akhrianti, Irma; Nugraha, Mohammad Agung
Jurnal Kelautan Tropis Vol 28, No 2 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i2.22714

Arung Dalam Village is one of the sub-districts in Koba District, Central Bangka Regency, which has a coastline of 4.7 km and a beach safety building (Seawall) 1.8 km long. It is important to measure the coastline in Arung Dalam Village because the beach topography is sloping and located right on the edge of the main road and close to residential areas, resulting in problems and threats for Arung Dalam Village. This research aims to determine the condition of changes in the coastline in 2013 and 2022 before the existence of a beach safety building (Seawall) and to find predictions of changes in the coastline in 2045. The methods used in this research are the MNDWI method and the Digital Shoreline Analysis System. The results of the research show that Arung Dalam Village Beach experienced changes in addition (accretion) and reduction (abrasion). Detection results show that from 2013 to 2022, the Arung Dalam Village Beach experienced a maximum change in addition (accretion) of 8.56 m at a rate of 0.53 m/year and a maximum reduction (abrasion) of -28.53 m at a rate of -1.75 m/year. Predictions made in 2045 in Zone B using the LRR method will result in a dominant barometric change of -35.32 m with a rate of -0.917 m/year, while using the EPR method, the maximum reduction (abrasion) will be -47.72 m with a rate of -1, 03 m/year. Therefore, in zone B, efforts need to be made to anticipate changes that will occur in the future. Kelurahan Arung Dalam merupakan salah satu kelurahan di Kecamatan Koba, Kabupaten Bangka Tengah yang memiliki panjang garis pantai sepanjang 4,7 km dan memiliki bangunan pengaman pantai (Seawall) sepanjang 1,8 km. Pentingnya melakukan pengukuran garis pantai di Kelurahan Arung Dalam karena topografi pantai yang landai dan berada tepat di pinggir jalan raya serta dekat dengan pemukiman penduduk ini mengakibatkan terjadinya permasalahan dan ancaman bagi Kelurahan Arung Dalam. Penelitian ini bertujuan untuk mengetahui kondisi perubahan garis pantai pada Tahun 2013 dan Tahun 2022 sebelum adanya bangunan pengaman Pantai (Seawall) serta mengetahui prediksi perubahan garis pantai pada tahun 2045. Metode yang digunakan dalam penelitian ini adalah metode MNDWI dan Digital Shoreline Analysis System. Hasil penelitian menunjukan bahwa Pantai Kelurahan Arung Dalam mengalami perubahan penambahan (akresi) dan pengurangan (abrasi). Hasil deteksi menunjukan bahwa 2013-2022 Pantai Kelurahan Arung Dalam mengalami perubahan penambahan (akresi) maksimum 8,56 m dengan laju 0,53 m/tahun dan pengurangan (abrasi) maksimum -28,53 m dengan laju -1,75 m/tahun. Prediksi yang dilakukan Pada tahun 2045 pada Zona B menggunanakan Metode LRR terjadi perubahan barasi yang dominan sebesar -35,32 m dengan laju -0,917 m/tahun sedangkan menggunakan metode EPR pengurangan (abrasi) maksimum sebesar -47,72 m dengan laju -1,03 m/tahun. Oleh karena itu, pada zona B perlu adanya Upaya untuk mengantisipasi perubahan yang akan terjadi dimasa yang akan datang.

Aktivitas Antioksidan dan Fotoproteksi Ekstrak Kasar Bakteri Berpigmen Asosiasi Gastropoda Cassidula nucleus Hanif, Marwa Irfan; Pringgenies, Delianis; Setyati, Wilis Ari
Jurnal Kelautan Tropis Vol 28, No 2 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i2.26824

Excessive UV radiation generates free radicals, damaging healthy skin cells. Bioactive compounds with photoprotection and antioxidant properties offer a promising treatment for this damage. Pigments, often sourced from marine microbes associated with marine organisms, are natural materials known for these capabilities. This study aimed to identify antioxidant and photoprotection activities in pigmented bacteria linked to gastropods. A source of pigments is marine microbes associated with marine organisms. This study aims to determine the antioxidant and photoprotection activities of pigmented bacteria associated with the gastropod. Gastropod samples were obtained from the mangrove ecosystem of Mangkang Semarang and bacteria were isolated by the spread plate method. This research method is explorative descriptive, includes colony characterization, bacteria mass culture and maceration extraction of bacteria using methanol, carotenoid content calculation, antioxidant and photoprotection activity test, compound preliminary analysis using Fourier Transform Infrared spectroscopy (FTIR) and molecular identification of bacteria. The results obtained 2 bacterial isolates derived from the gastropod Cassidula nucleus have colored colonies. Based on the calculation of the highest carotenoid content is in the isolate with the code MK.CN.3 amounting to 23.81 µg/g. Antioxidant activity test results from isolate MK.CN.3 showed IC50 value of 461 ppm with weak category and photoprotection value with SPF of 6.57 with extra protection category. Based on the analysis of crude extract, the pigment is suspected to contain carotenoids such as astaxanthin and β-carotene. The results of molecular identification showed that isolate MK.CN.3 is a strain of Isoptericola chiayiensis. Peningakatan radikal bebas akibat radiasi sinar UV berlebih pada kulit menyebabkan kerusakan sel kulit sehat. Penanganan kerusakan kulit yang disebabkan oleh paparan sinar ultraviolet (UV) dapat dilakukan melalui pemanfaatan senyawa bioaktif yang berfungsi sebagai agen fotoproteksi untuk melindungi kulit dari radiasi UV serta memiliki aktivitas antioksidan yang mampu menetralisir radikal bebas. Salah satu bahan alam yang memiliki kemampuan fotoproteksi dan antioksidan adalah pigmen. Salah satu sumber pigmen adalah mikroba laut yang berasosiasi dengan organisme laut. Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan dan fotoproteksi bakteri berpigmen asosiasi gastropoda. Sampel gastropoda diperoleh dari ekosistem mangrove Mangkang Semarang dan bakteri diisolasi dengan metode spread plate. Metode penelitian yang digunakan adalah deskriptif eksploratif, meliputi karakterisasi koloni, kultur masal bakteri dan ekstraksi bakteri secara maserasi menggunakan pelarut metanol, perhitungan kandungan karotenoid, uji aktivitas antioksidan dan fotoproteksi, analisis pendahuluan senyawa menggunakan Fourier Transform Infrared spectroscopy (FTIR) serta identifikasi bakteri asosiasi gastropoda secara molekuler. Hasil penelitian diperoleh 2 isolat bakteri yang berasal dari gastropoda Cassidula nucleus memiliki koloni berwarna. Berdasarkan perhitungan kandungan karotenoid tertinggi ada pada isolat dengan kode MK.CN.3 sebesar 23,81 µg/g. Hasil uji aktivitas antioksidan dari isolat MK.CN.3 menunjukkan nilai IC50 sebesar 461 ppm dengan kategori lemah dan nilai fotoproteksi dengan SPF sebesar 6,57 dengan kategori extra protection. Berdasarkan analisis ekstrak kasar pigmen diduga mengandung karotenoid jenis astaxanthin dan β – carotene. Hasil identifikasi molekuler menunjukkan bahwa isolat MK.CN.3 merupakan bakteri jenis Isoptericola chiayiensis.

Nilai Keanekaragaman Hayati Perikanan dengan Mengadopsi Kriteria OECM : Studi Kasus PAAP Teluk Kolono, Sulawesi Tenggara Siregar, Amelia Fransiska; Adrianto, Luky; Zairion, Zairion
Jurnal Kelautan Tropis Vol 28, No 2 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i2.26045

Fisheries Access Area Management Area (PAAP) of Kolono Bay as a connector, interaction relationship and ecosystem balance. This study aims to assess fisheries biodiversity using the Other Effective Area-Based of Conservation Measures (OECM) criteria for the Fisheries Access Area Management Area (PAAP) of Kolono Bay. Interview methods, Focus Group Discussion (FGD) were analyzed using Social Ecological Network Analysis (SENA), and biodiversity values. The results showed that the Social-Ecological System (SES) network in the PAAP of Kolono Bay contained a connectivity system of 27 components (nodes) and 46 relationships (edges). Resources Unit (RU) is an important variable in influencing the ecosystem of the resource system. In addition, fisheries biodiversity in this area showed a low value with a total of 17 families and 64 species found. The diversity and uniformity values were in the medium to high category, while dominance was in the low category or none dominated. The utilization status is obtained in 3 categories including: Least Concern (LC), Vulnerable (VU), and Not Evaluated (NT). The utilization status of less concern (LC) is more dominant indicating that the fish community in the area is considered not endangered. Keberadaan Pengelolaan Area Akses Perikanan (PAAP) Teluk Kolono sebagai konektivitas, hubungan interaksi dan keseimbangan ekosistem. Penelitian ini bertujuan untuk menilai keanekaragaman hayati perikanan dengan mengadopsi kriteria Other Effective Area-Based of Conservation Measures (OECM) terhadap kawasan Pengelolaan Area Akses Perikanan (PAAP) Teluk Kolono. Metode wawancara, Focus Group Discussion (FGD) dIanalisis menggunakan Social Ecological Network Analysis (SENA) , dan nilai biodoversitas. Hasil penelitian menunjukkan bahwa jejaring Sistem Sosial-Ekologi (SES) di PAAP Teluk Kolono terdapat konektivitas sistem sebanyak 27 komponen (node) dan 46 hubungan (edge). Resources Unit (RU) merupakan variabel penting dalam mempengaruhi keberlanjutan jejaring sistem sumberdaya. Selain itu, keanekaragaman hayati perikanan di kawasan ini mengindikasi nilai kelimpahan rendah dengan total 17 famili dan 64 spesies yang ditemukan. Nilai keaenakaragman dan keseragaman dalam kategori sedang sampai tinggi, sedangkan dominansi masuk kategori rendah atau tidak ada yang mendominasi. Status pemanfaatan didapatkan 3 kategori diantaraya : Least Concern (LC), Vulnerable (VU), dan Not Evaluated (NT). Status pemanfaatan least conern (LC) lebih mendominasi mengindikasikan bahwa komunitas ikan di kawasan dianggap tidak teranam kepunahan.

Pengaruh Jumlah Mikroplastik Terhadap Berat Ikan Pari yang Didaratkan di TPI Klandasan Balikpapan Dewi, Alya Prasasti; Eryati, Ristiana; Nurfadilah, Nurfadilah
Jurnal Kelautan Tropis Vol 28, No 2 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i2.24744

Microplastic is one of the plastic pollutants > 5mm in size that has an impact on life around the world, including marine organisms such as fish. This study aims to determine the type, colour, size and abundance. Linear regression analysis was used to determine the relationship between fish size and microplastic abundance in the digestion of stingrays landed at Klandasan Fish Landing Site Balikpapan. A total of 14 stingrays were collected in January 2024 from fishermen in Balikpapan coastal waters. Morphometric analysis of fish by measuring length (cm), width (cm) and weight (kg). Microplastics were extracted from fish digestion through dry deconstruction, followed by the addition of saturated NaCL, KOH 22% H2O2 30%, then filtered using Whatman paper with a vacuum pump. Three types of microplastics were found in stingray digestion with the percentage composition of fibre (54%), fragments (38%), and film (8%). The highest abundance of microplastics in samples with a length of 38 cm, a width of 43 cm and a weight of 2.1 kg was 8.8 particles/gr. The colours of microplastics found were 7 colours, namely black, brown, red, blue, green, yellow, and transparent. Regression test results There is a strong correlation between the length and weight of stingrays and the abundance of microplastics Mikroplastik merupakan salah satu polutan plastik yang berukuran > 5mm yang berdampak pada kehidupan seluruh dunia, termasuk organisme laut seperti ikan. Penelitian ini bertujuan untuk mengetahui tipe, warna, ukuran dan kelimpahan. Analisis regresi linier untuk mengetahui hubungan ukuran ikan dengan kelimpahan mikroplastik pada pencernaan ikan pari yang didaratkan di Tempat Pendaratan Ikan Klandasan Balikpapan. Total 14 ekor ikan pari yang dikumpulkan pada bulan Januari 2024 dari nelayan di perairan pesisir Balikpapan. Analisis morfometrik ikan dengan pengukuran Panjang (cm), Lebar (cm) dan berat (kg). Mikroplastik diekstraksi dari pencernaan ikan melalui destruksi kering, diikuti dengan penambahan NaCL jenuh, KOH 22% H2O2 30%, kemudian disaring menggunakan kertas Whatman dengan vacum pump. Tiga tipe mikroplastik ditemukan pada pencernaan ikan pari dengan komposisi persentase fiber ( 54%), fragmen (38%), dan film (8%). Kelimpahan mikroplastik tertinggi pada sampel dengan panjang 38 cm, lebar 43 cm dan berat 2,1 kg sebesar 8,8 partikel/gr. Warna mikroplastik yang di temukan sebanyak 7 warna yaitu hitam, coklat, merah, biru, hijau, kuning, dan transparan. Hasil uji regresi Terdapat korelasi yang kuat antara panjang dan berat ikan pari terhadap kelimpahan mikroplastik.

Pengaruh ENSO Terhadap Variabilitas Curah Hujan Dan Klorofil-A di Perairan Samarinda Zulfa, Istna Nabila; Wirasatriya, Anindya; Ismanto, Aris
Jurnal Kelautan Tropis Vol 28, No 2 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i2.22547

Samarinda is located along the Mahakam River, which is one of the largest rivers on the island of Borneo. The river stretches for approximately 920 kilometers, starting from the mountains in East Kalimantan and ending at the Makassar Strait. The Mahakam River plays an important role in the daily activities of the people of Samarinda. This study aims to analyze how rainfall intensity affects chlorophyll-a levels in Samarinda waters during the west and east seasons. The data used in this study came from satellite imagery. Sea surface temperature information was taken from the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) source, while chlorophyll data was obtained from The Ocean Color CCI (OC CCI). For rainfall, data was collected through the Global Satellite Measurement of Precipitation (GSMaP), and wind speed data was obtained from ASCAT. All temperature, wind, chlorophyll and rainfall data were spatially processed using IDL (Interactive Data Language) software. This study used data for 16 years, from January 2007 to December 2022. The results of the analysis show that in the Samarinda water area, there is a significant relationship between ENSO and rainfall in the west season, as indicated by a p value of 0.000 (<0.05). The correlation between ENSO and western season rainfall is -0.510, indicating a negative relationship with moderate strength, i.e. rainfall tends to decrease when El-Nino increases, and vice versa. Meanwhile, the relationship between ENSO and rainfall in the eastern season in the same area is also significant, with a p-value of 0.001. The correlation of -0.459 shows a negative direction and moderate correlation strength, which means that when El-Nino is strong, rainfall decreases. The relationship between ENSO and chlorophyll-a concentration is different. In the western season, the p value of 0.248 (>0.05) indicates that there is no significant relationship. The correlation value of -0.170 indicates a very weak negative relationship, meaning that when El Niño occurs, chlorophyll-a tends to decrease but not significantly. The same is true for the eastern season, where a p value of 0.615 indicates no significant relationship between ENSO and chlorophyll-a. The positive correlation of 0.074 is also very weak, meaning that when El Niño increases, chlorophyll-a increases slightly but this relationship is not strong. Samarinda berada di sepanjang aliran Sungai Mahakam, yang merupakan salah satu sungai terbesar di Pulau Kalimantan. Sungai ini membentang sepanjang kurang lebih 920 kilometer, bermula dari pegunungan di wilayah Kalimantan Timur dan berakhir di Selat Makassar. Sungai Mahakam memiliki peranan penting dalam aktivitas sehari-hari masyarakat Samarinda. Penelitian ini bertujuan untuk menganalisis bagaimana intensitas curah hujan memengaruhi kadar klorofil-a di wilayah Perairan Samarinda selama musim barat dan musim timur. Data yang digunakan dalam penelitian ini berasal dari citra satelit. Informasi suhu permukaan laut diambil dari sumber Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA), sedangkan data klorofil diperoleh dari The Ocean Color CCI (OC CCI). Untuk curah hujan, data dikumpulkan melalui Global Satellite Measurement of Precipitation (GSMaP), dan data kecepatan angin diperoleh dari ASCAT. Seluruh data suhu, angin, klorofil, dan curah hujan diolah secara spasial menggunakan perangkat lunak IDL (Interactive Data Language). Penelitian ini menggunakan data selama 16 tahun, yaitu dari Januari 2007 hingga Desember 2022. Hasil analisis menunjukkan bahwa di kawasan perairan Samarinda, terdapat hubungan yang signifikan antara ENSO dan curah hujan pada musim barat, yang ditunjukkan oleh nilai p sebesar 0,000 (< 0,05). Korelasi antara ENSO dan curah hujan musim barat bernilai -0,510, menandakan adanya hubungan negatif dengan kekuatan sedang, yaitu curah hujan cenderung menurun saat El-Nino meningkat, dan sebaliknya. Sementara itu, hubungan antara ENSO dan curah hujan pada musim timur di daerah yang sama juga signifikan, dengan p-value 0,001. Korelasi sebesar -0,459 menunjukkan arah hubungan yang negatif dan kekuatan korelasi sedang, yang berarti saat El-Nino kuat, curah hujan menurun. Berbeda halnya dengan hubungan ENSO dan konsentrasi klorofil-a. Di musim barat, nilai p sebesar 0,248 (> 0,05) menunjukkan bahwa tidak terdapat hubungan yang signifikan. Nilai korelasi sebesar -0,170 mengindikasikan hubungan negatif yang sangat lemah, artinya saat terjadi El-Nino, klorofil-a cenderung menurun namun tidak secara signifikan. Hal serupa juga ditemukan pada musim timur, di mana nilai p sebesar 0,615 menunjukkan tidak adanya hubungan yang signifikan antara ENSO dan klorofil-a. Korelasi positif sebesar 0,074 pun sangat lemah, yang berarti saat El-Nino meningkat, klorofil-a sedikit meningkat namun hubungan ini tidak kuat.

Studi Waveform Retracking Jason-2 di Pesisir Barat Daya Sumatera Nadzir, Zulfikar Adlan; Hasan, Muhammad Akmal
Jurnal Kelautan Tropis Vol 28, No 2 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i2.26228

Monitoring sea level changes in coastal areas is critical to understand ocean dynamics and their impact on the environment and human activities. Satellite altimetry has been the main tool in these studies, but its use in coastal areas still faces obstacles, especially due to variations in waveforms reflected from the sea surface. This study evaluates the accuracy of several altimetry waveform retracking methods (OCOG, Threshold 10%, and Threshold 30% ) on the southwest coast of Sumatra. The analysis was conducted using Jason-2 data on two passes, namely pass 077 and pass 153, with validation against two tide gauge stations nearby. Results showed that the Threshold 30% method provided a more accurate estimation of the Leading Edge Point (LEP) position than the other methods, with an average difference of only 0.1 gates (0.32%) from the reference value. Meanwhile, the OCOG method has the worst performance with a difference of 6.27 gates (20.22%), indicating its inability to handle coastal waveform variations on the location. Validation of the tide gauge data shows that retracking with a 10% Threshold improves the precision of Sea Surface Height (SSH) data with the highest IMP improvement value of 65.2% and the smallest standard deviation on the Threshold 30%. This finding confirms that choosing the right retracking method plays a crucial role in improving the accuracy of satellite altimetry in coastal areas. Therefore, the Threshold method is recommended for further analysis to improve the quality of altimetry data in coastal Indonesia. Pemantauan perubahan muka air laut di wilayah pesisir sangat penting untuk memahami dinamika laut dan dampaknya terhadap lingkungan serta aktivitas manusia. Satelit Altimetri telah menjadi alat utama dalam studi ini, tetapi penggunaannya di wilayah pesisir masih menghadapi tantangan, terutama akibat variasi bentuk waveform yang dipantulkan dari permukaan laut. Studi ini mengevaluasi keakuratan metode waveform retracking altimetri OCOG, Threshold 10%, dan Threshold 30% di pesisir barat daya Sumatra. Analisis dilakukan menggunakan data Jason-2 pada dua jalur lintasan, yaitu pass 077 dan pass 153, dengan validasi terhadap data pasang surut. Hasil penelitian menunjukkan bahwa metode Threshold 30% memberikan estimasi posisi Leading Edge Point (LEP) yang lebih akurat dibandingkan metode lainnya, dengan selisih rata-rata hanya 0,1 gate (0,32%) dari nilai referensi. Sementara itu, metode OCOG memiliki performa paling tidak akurat dengan selisih sebesar 6,27 gate (20,22%), yang mengindikasikan ketidakmampuannya dalam menangani variasi waveform di pesisir. Validasi terhadap data pasang surut menunjukkan bahwa retracking dengan Threshold 10% meningkatkan presisi data Sea Surface Height (SSH) dengan nilai peningkatan IMP tertinggi sebesar 65,2% dan standar deviasi terkecil pada metode Threshold 30%. Temuan ini menegaskan bahwa pemilihan metode retracking yang tepat berperan krusial dalam meningkatkan akurasi satelit altimetri di wilayah pesisir. Oleh karena itu, metode Threshold direkomendasikan untuk analisis lebih lanjut guna meningkatkan kualitas data altimetri di kawasan pesisir Indonesia.

Kondisi Eksisting Komunitas Mangrove di Pesisir Pantai Negeri Kaibobu Seram Bagian Barat, Maluku Pietersz, Janson Hans; Huliselan, Niette Vuca; Uneputty, Prulley Annette; Tuapattinaja, Maureen Alise
Jurnal Kelautan Tropis Vol 28, No 2 (2025): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v28i2.26024

The mangrove community of Kaibobu Village has an important role in supporting the lives of the community, the environment, and especially the marine tourism sector. In addition, the mangrove community on the coast of Kaibobu Village Beach is also inseparable from various threats from anthropogenic activities. Based on the importance of the existence of the mangrove community and the lack of information regarding the current condition of the mangrove community, it is necessary to conduct a study regarding the existing condition of the mangrove community so that it can be used as a basis for management activities. This study aims to analyze the condition of the area of the mangrove community, species composition, important value index, standing carbon storage, mangrove canopy closure, and mangrove health conditions. Sentinel-2B imagery was used in this study to assess the area and condition of the mangroves. Data collection on the potential of the mangrove community used the purposive sampling method, and a simple hemispherical photography technique was also applied to collect data on mangrove canopy cover. The mangrove standing carbon storage condition was analyzed using a non-destructive method, and the overall health condition of the mangrove community was estimated based on the Mangrove Health Index. The analysis showed that the mangrove community on the coast of Kaibobu Village is a reasonably large area, and seven types of mangroves were found in all observation plots. Based on the important value index, B. gymnorrhiza, S. alba, and C. tagal are the most dominant types at each research station. The highest carbon storage value of tree stands was found at station AP1, 176.20 tons/ha. Mangrove canopy cover is still relatively dense at all research stations. Then, the overall health condition of the mangroves based on MHI is dominated by moderate conditions with a percentage of area of 78.86%. Komunitas mangrove Negeri Kaibobu memiliki peranan penting dalam menunjang kehidupan masyarakat, lingkungan, dan khususnya sektor pariwisata bahari. Selain itu, keberadaan komunitas mangrove di pesisir Pantai Negeri Kaibobu juga tidak terlepas dari berbagai ancaman dari aktivitas antropogenik. Berdasarkan pentingnya keberadaan komunitas mangrove dan masih kurangnya informasi terkait kondisi komunitas mangrove saat ini, Maka perlu dilakukan kajian terkait kondisi eksisting komunitas mangrove sehingga dapat dijadikan sebagai dasar dalam kegiatan pengelolaan. Penelitian ini bertujuan untuk menganalisis kondisi luasan komunitas mangrove, komposisi jenis, indeks nilai penting, simpanan karbon tegakan, tutupan kanopi mangrove, dan kondisi kesehatan mangrove. Citra sentinel-2B digunakan dalam penelitian ini untuk menilai luas dan kondisi mangrove. Pengumpulan data potensi komunitas mangrove menggunakan metode purposive sampling, kemudian teknik hemispherical photography sederhana di aplikasikan juga untuk mencuplik data tutupan tajuk mangrove. Kondisi simpanan karbon tegakan mangrove dianalisis dengan metode non-destruktif, dan kondisi kesehatan komunitas mangrove secara keseluruhan diestimasi berdasarkan Mangrove Health index. Hasil analisis menunjukkan bahwa komunitas mangrove di pesisir Negeri Kaibobu mempunyai wilayah yang cukup luas serta ditemukan tujuh jenis mangrove pada seluruh petak pengamatan. Jenis B. gymnorrhiza, S. alba dan C. tagal merupakan jenis yang paling dominan pada setiap stasiun penelitian berdasarkan indeks nilai pentingnya. Nilai simpanan karbon tegakan pohon tertinggi terdapat pada stasiun AP1 yaitu sebesar 176,20 ton/ha. Tutupan tajuk mangrove masih tergolong padat di seluruh stasiun penelitian. Kemudian kondisi kesehatan mangrove secara keseluruhan berdasarkan MHI didominasi oleh kondisi moderate dengan persentase luas wilayah sebesar 78,86%.

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Location Kota semarang, Jawa tengah INDONESIA

Abstract

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Contact Name
-

Contact Email
-

Phone
-

Journal Mail Official
-

Editorial Address
-

Location
Kota semarang,

Jawa tengah

INDONESIA