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Jurnal Kelautan Tropis
Published by Universitas Diponegoro
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Articles 451 Documents
Environmental Characteristic of Phyllophorus sp. (Echinodermata, Holothuroidea, Phyllophoridae) Habitat in the Madura Strait, Indonesia Widianingsih Widianingsih; Retno Hartati; Hadi Endrawati
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.v26i3.15064

Abstract

Information on the environmental characteristics of many sea cucumber habitat is limited, despite these species exhibiting rapid exploitation and may lead to depletion. The present study combined a survey on many seawaters and sediment characteristics of habitat valuable aspidochirote holothurian, Sea Ball Cucumber, Phyllophorus sp. to compare with location with no sea cucumber in Madura Strait, Indonesia. Data from detailed surveys were used to compare both locations with measures of physical and chemical seawater parameters including temperature, salinity, dissolved oxygen, pH, phosphate, nitrate, ammonia, chlorophyll-a, total suspended solids, light transparency, and depth of water. The comparison was also carried out on physical and chemical parameters of surface sediment, i.e. phosphate, nitrate, ammonia, chlorophyll-a, grain size, total organic matter, and carbon-organic content. The data then were analyzed using Mann-Whitney U-Non Parametric Test with SPSS v. 16.  The result revealed that there were significant differences between sediment characteristics of Sea Ball Cucumber habitat and no Sea Ball cucumber location, but not for seawater. Seawater parameter value in Madura Strait showed in the range required for its life. This analyzes proved the importance of sediment characteristics for Phyllophorus sp. As benthic deposit feeders, they did not only utilize substrate underneath the body for its habitat but also primarily to supply their natural food. 
Study on the anti-vibrio activity of marine fungi Aspergillus sydowii and Rhizopus sp. using OSMAC Approach Galank Fad'qul Janarkho; Agus Trianto; Sri Sedjati; Rindiani Puja Listari
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.v26i3.20451

Abstract

Shrimp is one of the major aquaculture products in Indonesia. However, shrimp culture faces the peril of Vibriosis, a disease caused by the bacteria genus of Vibrio.  Marine sponge-associate microbes are recognized for their potential as sources of antibacterial agent. The fungus Aspergillus sydowii isolate that used in this research originally isolated from marine sponge collected in Lampung Bay. The fungus was grown in various media e. g. Malt extract agar (MEA), MEA-Tempeh broth (MEA-T), and tofu dregs (TD) under various pH (5.5, 7.5, and 9.5).  The fungus also be culture as mono-culture and co-culture with Rhizopus sp. The anti-vibrio assay was conducted using disk diffusion method. Based on anti-vibrio assay, the fungus A. sydowii and Rhizopus sp. didn’t show any correlation with the anti-vibrio compound produced. The fungus Rhizopus sp. cultivated in tofu dregs media (TD) at pH 5.5 exhibited the highest potential for inhibiting against V. alginolyticus (5.85±0.24 mm), V. harveyi (5.20±0.20 mm), and V. vulnificus (4.33±0.15 mm), while the co-culture (A. sydowii and Rhizopus sp.) in TD media and pH 7.5 against V. parahaemolyticus (5.55±0.86 mm). The fungus cultured in pH 7.5 can promotes the potential inhibition zone than a pH 9.5. 
Estimasi Cadangan Karbon Pada Ekosistem Mangrove Di Desa Pengudang Kecamatan Teluk Sebong Kabupaten Bintan Diah Alviana; Rika Anggraini; Jelita Rahma Hidayati; Ita Karlina; Febrianti Lestari; Dony Apdillah; Agung Dhamar Syakti; Dermawati Sihite
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.v26i3.18326

Abstract

Mangrove have a role in the absorption and storage of carbon from the atmosphere, which is stored in the form of biomass and sediment, so that mangroves have enormous potential in mitigation global climate change because they can reduce greenhouse gas emission is carbon. Mangrove store carbon in carbon pools including above ground biomass, below ground biomass, litter or dead wood, and soil. The purpose of this study was to calculate the value of carbon stock and carbon sequestration in mangroves in Pengudang Villages, Teluk Sebong District, Bintan Regency. This research was conducted in September – October 2022, the research method used purposive sampling non-destructive method with allometric model and sediment sampling was carried out at 30 cm intervals until the discovery of humus soil. The result of biomass calculations were then converted into carbon stock values and mangrove carbon sequestration. Data analysis was carried out by calculating biomass, carbon stock value and carbon sequestration in mangroves in Pengudang Villages, Teluk Sebong District, Bintan Regency. The result showed the total biomass value was 498,77 tons/ha, the carbon stock value was 1203,27 tonsC/ha, while the carbon sequestration value was 4412,05 tonsC/ha.  Mangrove berperan dalam penyerapan dan penyimpanan karbon dari atmosfer yang disimpan dalam bentuk biomassa dan sedimen, sehingga mangrove memiliki potensi yang sangat besar dalam mitigasi perubahan iklim global karena dapat mengurangi emisi gas rumah kaca yaitu karbon. Mangrove menyimpan karbon dalam kantong karbon diantaranya adalah biomassa bagian atas, biomassa bagian bawah, serasah atau kayu mati dan tanah.  Tujuan penelitian ini untuk menghitung nilai stok karbon dan sekuestrasi karbon pada mangrove di Desa Pengudang Kecamatan Teluk Sebong Kabupaten Bintan. Penelitian ini dilakukan pada bulan September – Oktober tahun 2022, metode penelitian yang digunakan adalah purposive sampling metode non-destruktif dengan model alometrik dan dilakukan pengambilan sampel sedimen per-interval 30cm hingga ditemukannya tanah humus. Hasil perhitungan biomassa kemudian dilakukan konversi nilai stok karbon dan sekuestrasi karbon mangrove. Analisis data dilakukan dengan menghitung biomassa, nilai stok karbon dan sekuestrasi karbon pada mangrove di Desa Pengudang Kecamatan Teluk Sebong Kabupaten Bintan. Hasil penelitian menunjukkan nilai total biomassa 498,77 ton/ha nilai stok karbon adalah 1203,27 tonC/ha sedangkan nilai sekuestrasi karbon adalah 4412,05 tonC/ha.
Kelimpahan dan Karakteristik Mikroplastik di Perairan Kolam Labuh dan Sungai Blangor Kecamatan Palang, Tuban Fawaz Muhammad Sidiqi; Bambang Yulianto; Jusup Suprijanto
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.v26i3.18498

Abstract

Microplastic contamination has been identified in Indonesian water bodies, raising environmental concerns. This study investigates microplastic abundance and characteristics in water and sediment of Palang Waters (Kolam Labuh and Sungai Blangor) in Tuban. Seawater and river samples were collected using a 75 µm mesh plankton net. Microplastics were quantified under microscopy, and polymer analysis utilized Fourier Transform Infrared (FT-IR) spectroscopy. Seawater showed an abundance of 40,000 ± 11,357.82 particles/m3, with 48.75% fragments, 44.58% fibers, and 6.67% granules. River microplastic abundance was 13,333.33 ± 5,033.23 particles/m3, comprising 82.5% fibers, 10% fragments, and 7.5% granules. Sediment's average microplastic abundance was 226.67 ± 83.27 particles/m3, including 53% fibers, 29% fragments, and 18% granules. Statistical analysis highlighted significant differences in microplastic abundance among seawater, river water, and sediment (P-Value = 0.001). Notable differences existed between seawater and river water (P-value = 0.009), and seawater and sediment (P-value 0.001), but not between river water and sediment (P-value = 0.143). Polymer analysis revealed polymers such as Polyvinyl Chloride (PVC), Polyethylene (PE), and High-Density Polyethylene (HDPE). This research offers insights into microplastic presence, aiding in understanding aquatic pollution.  Kontaminasi mikroplastik telah terjadi di beberapa perairan Indonesia. Mikroplastik memiliki ukuran ≤5 mm. Penelitian ini bertujuan untuk mengetahui kelimpahan dan karakteristik mikroplastik pada air dan sedimen di Perairan Kolam Labuh dan Sungai Blangor, Kecamatan Palang, Tuban. Sampel air laut dan sungai diambil menggunakan plankton net dengan ukuran mesh 75 µm. Kelimpahan dan bentuk mikroplastik dihitung dan diamati menggunakan mikroskop, dan analisis polimer menggunakan uji Fourier Transform Infrared (FT-IR). Hasil penelitian menunjukkan bahwa kelimpahan mikroplastik pada air laut sebanyak 40.000 ± 11.357,82 partikel/m3, bentuk fragmen sebanyak 48,75 %, kemudian fiber sebanyak 44,58 % dan granules sebanyak 6,67% pada air laut. Sedangkan di Sungai didapatkan kelimpahan mikroplastik sebanyak 13.333,33 ± 5.033,23 partikel/m3, bentuk fiber sebanyak 82,5 %,fragmen 10 % dan fiber 7,5 %. Kelimpahan rata-rata mikroplastik pada sedimen ialah 226,67 ± 83,27 , bentuk fiber sebanyak 53%, fragmen 29% dan granules 18%. Hasil penelitian juga menunjukkan adanya perbedaan kelimpahan mikroplastik pada air laut, sungai dan sedimen (P-Value = 0,001). Perbedaan kelimpahan mikroplastik terjadi antara air laut dengan air sungai (P-value = 0,009) dan antara air laut dengan sedimen (P-value 0,001), sedangkan antara air sungai dan sedimen tidak terjadi perbedaan (P-value = 0,143). Hasil analisis polimer menunjukkan jenis polimer yang ditemukan meliputi Polivinil Klorida (PVC), Polyethylene (PE) dan High-Density Polyethylene (HDPE). 
Komposisi Makanan Ikan Baronang (Siganus guttatus) pada Ekosistem Lamun di Perairan Kota Tanjungpinang Uli Rohana Malau; Aditya Hikmat Nugraha; Ahmad Zahid
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.v26i3.19795

Abstract

The survival of fish in the waters is strongly influenced by the availability of food. The purpose of this study was to analyze the types of food for baronang fish and determine the selectivity of food for baronang fish in seagrass ecosystems in Tanjungpinang waters. This research was conducted in May 2023 at three stations, namely Sekatap Waters (ST I), Madong Waters (ST II), and Sebauk Waters (ST III). The research data collection method was carried out by purposive sampling. Fish samples were obtained from catches using 2-inch gill nets. Epiphyte sampling on seagrass leaves was carried out randomly. The total number of fish obtained at station I was 8 fish, 10 fish for station II, and 7 fish for station III. The catches at each station were dissected and collected from their digestive tract and then preserved for analysis in the laboratory. Analysis of the data used is the index of propenderance and electivity index. The results obtained in this study were the type of food for baronang fish (S. gutttatus) found in Tanjungpinang waters consisting of groups of microalgae from the class Bacillariophyceae (Flagilaria, Coscinodiscus, Diatoma, Nitzschia, Gyrosigma, Melosira, Rhizosolenia, and Rhabdonema), Euglenophyceae (Trachelomonas), Dinophyceae (Alexandrium), Chlorophyceae (Closteriopsis), Cyanophyceae (Oscilatoria and Audouinella), Crysophyceae (Vaucheria), Rhodophyceae (Polisiphonia and Bostrychia), group of nematodes from class Secernentea (Hirschmanniella) and Adenophorea (Anaplectus), group of crustaceans from class Branchiopoda (Diaphanosoma), shrimp leg pieces (unidentified), and detritus group. Baronang fish choosing food in their surroundings. Kelangsungan hidup ikan di perairan sangat dipengaruhi oleh ketersediaan makanan. Tujuan penelitian ini adalah untuk menganalisis jenis makanan ikan baronang dan menentukan pemilihan makanan ikan baronang pada ekosistem lamun di perairan Tanjungpinang. Penelitian ini dilaksanakan pada bulan Mei 2023 pada tiga stasiun yaitu di Perairan Sekatap (ST I), Perairan Madong (ST II), dan Perairan Sebauk (ST III). Metode pengambilan data penelitian dilakukan secara purpossive sampling. Sampel ikan diperoleh dari hasil tangkapan menggunakan jaring insang berukuran 2 inchi. Pengambilan epifit pada daun lamun dilakukan secara acak. Total jumlah ikan yang diperoleh pada stasiun I yaitu 8 ekor, stasiun II 10 ekor, dan stasiun III 7 ekor. Hasil tangkapan pada masing-masing stasiun dibedah dan mengambil saluran pencernaannya lalu diawetkan untuk dianalisis di laboratorium. Analisis data yang digunakan yaitu Index of propenderance dan electivity index. Adapun hasil yang didapatkan pada penelitian ini yaitu jenis makanan ikan baronang (S. gutttatus) yang ditemukan di perairan Tanjungpinang terdiri kelompok mikroalga dari kelas Bacillariophyceae (Flagilaria, Coscinodiscus, Diatoma, Nitzschia, Gyrosigma, Melosira, Rhizosolenia, dan Rhabdonema), Euglenophyceae (Trachelomonas), Dinophyceae (Alexandrium), Chlorophyceae (Closteriopsis), Cyanophyceae (Oscilatoria dan Audouinella), Crysophyceae (Vaucheria), Rhodophyceae (Polisiphonia dan Bostrychia), Kelompok nematoda dari kelas Secernentea (Hirschmanniella) dan Adenophorea (Anaplectus), Kelompok crustacea dari kelas Branchiopoda (Diaphanosoma), potongan kaki udang (tidak teridentifikasi), dan Kelompok detritus. Ikan baronang memilih makanan yang ada di lingkungannya. 
Keberadaan Gastropoda Mangrove Pasca 18 Tahun Tsunami dan 16 Tahun Rehabilitasi Pantai di Kota Banda Aceh Syahrial Syahrial; C.M.N. ‘Akla; Riri Ezraneti; Repki Prasetyo; Shela Annisa Batubara; Jasmine Wiyanda Fadillah; Reslina Tumangger; Helda Diah Ananda; Muhammad Afif Tri Putra
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.v26i3.15987

Abstract

The purposes of the reasearch that was conducted on July 2022 are to determine the biodiversity, composition, density, community index, correlation and contribution of gastropods on 18 year post tsunami and 16 year coastal rehabilitation in research observation of Banda Aceh. The method used is purposive sampling with 4 observation stations. Gastropods were collected using a quadratic transect perpendicular to the shoreline. PCA analysis was carried out to determine the level of contribution of gastropod species based on observation stations, while SIMPER and CA analyzes were carried out to compare and classify gastropod communities. A total of 8 families, 8 genera, 10 species and 6945 ind gastropods were found with densities ranging from 37.55 – 136.60 ind/m2. The highest diversity index was found at Station II (0.63), the highest uniformity index was found at Station III (0.86) and the highest dominance index was found at Station I (0.99). Gastropods Nerita planospira, Cassidula aurisfelis, C. nucleus, Sphaerassiminea miniata and Oncidium sp. closely related to Rhizophora mucronata and Avicennia alba growing on muddy substrates, while Morula iostoma, Cerithidea cingulata, Littoraria melanostoma, Nassarius olivaceus and L. scabra were closely related to R. mucronata growing on sandy mud substrates. Furthermore, C. cingulata species contributed at Stations I and IV, while C. aurisfelis species contributed at Stations II and III.  Kajian dilakukan pada bulan Juli 2022 yang bertujuan untuk mengetahui biodiversitas, komposisi, kepadatan, indeks komunitas serta keterkaitan dan kontribusi gastropoda terhadap stasiun pengamatan pasca 18 tahun tsunami dan 16 tahun rehabilitasi pantai di Kota Banda Aceh. Metode yang digunakan adalah purposive sampling dengan 4 stasiun pengamatan. Gastropoda dikumpulkan menggunakan transek kuadrat yang tegak lurus garis pantai. Analisis PCA dilakukan untuk mengetahui tingkat kontribusi spesies gastropoda berdasarkan stasiun pengamatan, sedangkan analisis SIMPER dan CA dilakukan untuk membandingkan serta mengklasifikasikan komunitas gastropodanya. Sebanyak 8 famili, 8 genus, 10 spesies dan 6945 ind gastropoda ditemukan dengan komposisi gastropoda antar stasiun pengamatannya berbeda nyata (p = 0.000) serta kepadatan gastropodanya berkisar antara 37.55 – 136.60 ind/m2. Indeks keanekaragaman tertinggi ditemukan pada Stasiun II (0.63), indeks keseragaman tertinggi ditemukan pada Stasiun III (0.86) dan indeks dominasi tertinggi ditemukan pada Stasiun I (0.99). Gastropoda Nerita planospira, Cassidula aurisfelis, C. nucleus, Sphaerassiminea miniata dan Oncidium sp. berkaitan erat dengan Stasiun II dan III (substratnya berlumpur), sedangkan Morula iostoma, Cerithidea cingulata, Littoraria melanostoma, Nassarius olivaceus dan L. scabra berkaitan erat dengan Stasiun I dan IV (substratnya lumpur berpasir). Selanjutnya, spesies C. cingulata memiliki kontribusi di Stasiun I maupun IV, sedangkan spesies C. aurisfelis memiliki kontribusi di Stasiun II maupun III.
Uji Akurasi Beberapa Algoritma Material Padatan Tersuspensi Menggunakan Citra Sentinel-2A di Muara Banjir Kanal Timur Semarang Maulana Al Faridzie; Lilik Maslukah; Dwi Haryo Ismunarti; Anindya Wirasatriya
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.v26i3.17496

Abstract

Total suspended solids (TSS) are one of the variables that determine water quality and are one of the factors influencing the sedimentation process in estuarine waters. The use of conventional methods has high accuracy but is inefficient in terms of cost and time. One of the water quality monitoring (TSS) solutions is to use a TSS concentration prediction algorithm that is specific to each water. The purpose of this study was to test the accuracy performance of several algorithms from other waters when applied to the Estuary of Banjir Kanal Timur (BKT). The method used is water quality sampling of 100 stations which is carried out simultaneously with the passing time of the Sentinel-2A image. The data is then used as a reference for the TSS concentration value in the algorithm validation test for predicting TSS concentrations in the waters of the estuary of BKT. The prediction algorithms of TSS concentration used are Parwati, Wirasatriya, LEL, and Lemigas algorithms.  The statistical parameters of MAPE, RMSE, and coefficient of determination (R2) were used to test the error. The most appropriate algorithm for evaluating the field value is Wirasatriya’s algorithm. The validation test is RMSE = 9.1694 and MAPE = 15.9984%. The resulting regression model between the best image prediction data (Wirasatriya) and field data obtained the coefficient of determination, R2 = 0.5441. The TSS monitoring in the BKT estuary is recommended to use Wirasatriya's algorithm for Sentinel-2, proving its validity and/or creating a specific algorithm for the BKT estuary waters. Each region has unique characteristics, so it needs to be generated. Material padatan tersuspensi (MPT) merupakan salah satu variabel yang menentukan kualitas air dan menjadi salah satu faktor yang mempengaruhi proses sedimentasi di perairan muara. Penggunaan metode secara konvensional memiliki akurasi tinggi, akan tetapi kurang efisien secara biaya dan waktu. Salah satu solusi pemantauan kualitas air (MPT) adalah menggunakan algoritma prediksi konsentrasi MPT yang sifatnya spesifik untuk masing-masing perairan. Tujuan penelitian ini adalah melakukan uji validasi untuk menentukan nilai error yang dihasilkan dari beberapa algoritma, apabila diaplikasikan pada perairan Muara Banjir Kanal Timur(BKT) Semarang. Metode yang digunakan adalah pengambilan sampel kualitas air sebanyak 100 stasiun yang dilaksanakan bersamaan dengan saat passing time citra Sentinel-2A. Data tersebut kemudian dijadikan acuan nilai konsentrasi MPT dalammenguji kinerja algoritma untuk prediksi MPT pada perairan Muara BKT. Algoritma prediksi konsentrasi MPT yang digunakan adalah algoritma Parwati, Wirasatriya, LEL, dan Lemigas.  Pengujian error dilakukan dengan beberapa parameter statistik yaitu MAPE, RMSE, dan koefisien determinasi (R2). Hasil algoritma yang terbaik terhadap nilai di lapangan adalah algoritma Wirasatriya, dengan nilai RMSE = 9,1694 dan MAPE = 15,9984%. Model regresi yang dihasilkan antara data prediksi citra terbaik (Wirasatriya) terhadap data lapangan didapatkan nilai koefisien determinasi,  R2 = 0,5441. Diharapkan untuk pemantauan MPT di muara BKT dan sekitarnya berdasarkan citra Sentinel 2, dapat menggunakan algoritma Wirasatriya yang telah terbukti lebih akurat dan (atau) dilkembangkan algoritma baru yang lebih spesifik. Setiap wilayah memiliki karakteristik yang unik, sehingga pengembangan algoritma sangat diperlukan.
Impact of Climate Change on Coral Reefs Degradation at West Lombok, Indonesia Susanna Nurdjaman; Muhammad Ikram Nasution; Ofri Johan; Gandhi Napitupulu; Ejria Saleh
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.v26i3.18540

Abstract

Coral reefs are one of the ecosystems that provide economic and environmental benefits to coastal communities in Indonesia. However, coral reef ecosystems are also one of the ecosystems threatened by climate change at the local scale. The waters of North Sekotong, West Lombok, Indonesia, are a tropical coastal system with beautiful coral reefs and marine ecosystems. Coral reef damage has been widespread in this area due to increased water temperatures. Increased water temperature results in coral reef degradation. Field surveys were conducted on May 23-28, 2016, in collaboration with the Marine and Coastal Resources Research and Development Center, Ministry of Marine Affairs and Fisheries, and coral reef mapping using Landsat 7 and Landsat 8 during 2002 - 2016 as well as processing monthly sea surface temperature (SST) data from the AquaModis and Oi SST V2 satellites and daily SST data from the NOAA Coral Reef Watch satellite. Changes in coral cover area were compared with temperature changes due to climate change. The increase in temperature creates a hotspot phenomenon in the coral reef ecosystem, resulting in coral reef degradation. The results showed that coral reefs in this area have degraded by 17.55% or 78.21 Ha from 455.68 Ha (2002) to 367.46 Ha (2016), with a degradation rate of 2.8 Ha/year in 2002 - 2014; 8.1 Ha/year (2014 - 2014) and 36 Ha/year (2015 - 2016) caused by an increase in SST which caused a hotspot phenomenon with a high enough intensity that there was an increase in temperature in 2016 which reached 9.77oC.
Catatan Pertama Distribusi Tridacna noae (Röding, 1798) dari Perairan Kepulauan Kei, Maluku Teddy Triandiza; Udhi Eko Hernawan; Agus Kusnadi
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.v26i3.18421

Abstract

The giant clams are the biggest  living bivalves that not only play a  vital role in coral reef ecosystem, but also as a food provider for coastal inhabitant. One of these species was Tridacna noae which is a crpyctic species due to morphoplogial characteristic similarity and habitat preferences with Tridacna maxima. Tridacna noae was recorded at the first time found in Kei Islands on November and December 2017 based on morphological characteristic and DNA barcoding analysis. This research found 8 individu of T. Noae in total, 7 individu was found in Kur Island and one individu from Ohoidertom at 2-3 m depth. The mantle pattern of T. noae was very unique and can be used to distinguished from T. maxima. Special feature of ormanent mantle of T. noae indicated with oval-shape patch with white line on the edge, has hyaline organ scattered along the margin of mantle and the presence of papillae that clearly seen. The result on Blasting from GenBank NCBI for COI sequence of giant clam sample revealed that 99.79%-100% was identical with T. noae species. Furthermore, result on genetic distance analysis of T. noae sample from Kei Island compare with T.noae from GenBank was 0.00-0.051, while genetic distance value compare with T. maxima was 0.159 – 0.205. The new finding of T. noae in Kei Island has added the number of giant clam species recorded previously become 7 species. This finding was also has enhanced the information on biogeographical distribution of T.noae in Indonesia.  Kerang kima merupakan kelompok bivalvia berukuran paling besar yang memlilki peranan penting di ekosistem terumbu karang serta menjadi sumber nutrisi bagi masyarakat peisir. Salah satu species kima adalah Tridacna noae yang bersifat cryptic spesies karena memiliki banyak kesamaan karakteristik morfologi dan preferensi habitat dengan T. Maxima. T. noae tercatat pertama kali ditemukan di Perairan Kepulauan Kei pada bulan November dan Desember 2017 berdasarkan pengamatan karekteristik morfologi dan aplikasi DNA barcoding. Hasil peneltian menemukan delapan individu T. noae, tujuh individu ditemukan di Perairan Pulau Kur, satu individu ditemukan di Perairan Ohoidertoom dengan kedalaman perairan 2-3 m. Ornamen mantel T. noae sangat khas dan dapat digunakan untuk membedakan dari T. maxima. Ornamen mantel ditandai dengan patch berbentuk oval terpisah dengan garis putih di tepi, memiliki organ hialin yang tersebar di sepanjang margin mantel, dan kehadiran papila yang terlihat jelas. Hasil blasting di GenBank NCBI untuk sekuens COI sampel kima menghasilkan tingkat kemiripan 99.79%-100% (identik) dengan T. noae. Hasil analisis jarak genetik sampel T. noae asal Kepulauan Kei dengan T. noae Genbank adalah sebesar 0.00 hingga 0.051, sedangkan jarak genetik dengan T. maxima adalah 0.159 hingga 0.205. Temuan T. noae di Kepulauan Kei menambahkan jenis kima yang tercatat sebelumnya di Kepulauan Kei menjadi 7 jenis. Temuan ini juga menambahkan lebih banyak informasi tentang distribusi geografis T. noae di Indonesia
Seagrass Meadow Distribution Mapping in the Coastal Lagoon of Buan Island, Anambas Dominikus Yoeli Wilson Laia; Ganang Wibisono; Eddy Handoko; Gita Endang Palufi; Fajar Kurniawan; Syofyan Roni; Muhammad Alrizky Ratno Budiarto
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.v26i3.20450

Abstract

Seagrasses are vital monocotyledonous marine flowering plants that serve as essential food sources for megaherbivores, contribute significantly to organic carbon production, and offer a multitude of crucial ecosystem services. Preserving seagrass habitats is of utmost importance, but the lack of comprehensive spatial data poses challenges to conservation efforts. The Anambas Islands, consisting of 255 small islands in the Natuna Sea, the southern part of the South China Sea, exemplify the scarcity of seagrass data, with the current distribution map only covering the Central and East Siantan region. In this study, our aim was to map the Buan coastal lagoon, where previous visual interpretation of Google Earth imagery suggested the presence of seagrasses. To achieve this, we carried out a drone survey and collected field data to classify and map the substrate types in the study area. The field survey documented four species in the location: T. hemprichii, E. acoroides, H. ovalis and S. isoetifolium, thereby expanding the known seagrass species in Anambas to nine. By employing a pixel-based classification of orthophotos, we achieved a promising overall accuracy of 69.5%. Our findings demonstrated that imageries from the Google Earth platform are viable alternatives for identifying seagrass meadows and can be utilized to support seagrass mapping efforts. This discovery offers valuable support for future seagrass mapping initiatives, especially at a local scale. Ultimately, our study contributes to the broader understanding of seagrass distribution in the Anambas Islands, and emphasizes the importance of further exploration to support conservation efforts in the seagrass ecosystem.