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Jurnal Kelautan Tropis
Published by Universitas Diponegoro
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Articles 451 Documents
Prevalensi Penyakit Karang di Pulau Menjangan Besar Karimunjawa Nining Nursalim; Agus Trianto; Muhammad Syaifudien Bahry; Dwi Haryanti; Raden Ario; Raja Aditia Sahala Siagian; Akhmad Tri Prasetyo
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.13208

Abstract

Coral disease can cause coral damage on Menjangan Besar Island, Karimunjawa. Floating net cages adjacent to coral reefs can affect coral health. Floating net cages can affect water quality by adding nutrients, such as nitrate (205.6 and phosphate 39.2/ton fish production). Nutrients and environmental factors can trigger and cause coral disease. The purpose of this study was to determine the effect of the existence of floating net cages on the prevalence of coral disease on Menjangan Besar Island, Karimunjawa. The research was conducted using a survey method, data collection using a proportional method, the results of the data will be analyzed descriptively. The results of the study found Black Band Disease, Brown Band Disease, Ulcerative White Pox, White syndrome, Yellow Bloch Disease, Pigmentation responses, White Plague and White Band Disease. Water parameters such as temperature ranged from 30.71-30.750C, salinity 32.7-33.20/00, current velocity 0.03-0.06 m/s, nitrate 0.586-1,128 mg/L and phosphate 0.064-0.133 mg/ L. The most common disease is Ulcerative White Pox. The prevalence of coral disease is influenced by the presence of floating net cages, it can be seen in A1, A2 and A3 with prevalence values (39.85, 43.61 and 33.14) which are higher than B1 and B2 (14.41 and 10,6).  Penyakit karang dapat menyebabkan kerusakan karang di Pulau Menjangan Besar Karimunjawa. Karamba jaring apung yang berdampingan dengan terumbu karang dapat mempengaruhi kesehatan karang. Karamba jaring apung dapat mempengaruhi kualitas air dengan menambah nutrien, seperti Nitrat (205,6 dan fosfat 39,2/ton produksi ikan. Nutrien dan faktor lingkungan dapat menjadi pemicu dan penyebab penyakit karang. Tujuan penelitian ini untuk mengetahui pengaruh keberadaan karamba jaring apung terhadap prevelensi penyakit karang di Pulau Menjangan Besar Karimunjawa. Penelitian dilakukan dengan metode survei, pengambilan data dengan metode porposif, hasil data akan disanalisis secara deskiptif. Hasil penelitian ditemukan penyakit Black Band Disease, Brown Band Disease, Ulcerative White Pox, White syndrome, Yellow Bloch Disease, Pigmentation responses, White Plague dan White Band Disease. Parameter perairan  seperti temperatur berkisar 30,71-30,750C, salinitas 32,7-33,20/00, kecepatan arus 0,03-0,06 m/s, nitrat  0,586-1,128 mg/L dan fosfat 0,064-0,133 mg/L. Penyakit paling banyak ditemukan adalah Ulcerative White Pox. Prevelensi penyakit karang dipengaruhi oleh keberadaan karamba jaring apung, dapat terlihat pada A1, A2 dan A3 dengan nilai prevalensi (39,85, 43,61 dan 33,14) yang lebih tinggi jika dibandingkan dengan B1 dan B2 (14,41 dan 10,6).
Kontaminasi Mikroplastik pada Perna viridis di Teluk Lampung Zakiyah Rahim; Neviaty Putri Zamani; Meutia Samira Ismet
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.12722

Abstract

Fisheries activity in Lampung Bay which has been very active in recent years is the cultivation of green mussels (P. viridis) for consumption. Located in Teluk Betung Timur sub-district, this is considered appropriate because of the environmental parameters that support the life of P. viridis. The location of P. viridis cultivation is not far from coastal settlements (±500-600 m from settlements). Anthropogenic activities of coastal residents as well as the use of plastic materials in the cultivation are concerned to be the source of microplastic contamination that found in P. viridis. This study aims to determine the presence and characteristics of microplastics in P. viridis as well as to compare the abundance of microplastics in the gills and digestive organs. Taking 30 P. viridis by purposive sampling with homogeneous size. The samples were analyzed by microplastics in chemical oceanography and biology micro Laboratory, FPIK, IPB University. P. viridis tissue was destructed by using 10% KOH solution at a ratio of 1:3 (m/v) at 60 °C for 24 hours and then filtered using a 1.6 µm Whatman GF/A filter paper. Abundance of microplastics in whole soft tissue were 0.53±0.7 mgl/g. The gill organs were found to be more microplastic than the digestive organs (p<0.05). The fragments microplastic is most commonly found in intact tissues and digestive organs, while fiber is mostly found in the gills of P. viridis. Blue color and size <100 µm were most commonly found in intact tissues, gills and digestive organs of P. viridis.  Kegiatan perikanan di Teluk Lampung yang sangat aktif dalam beberapa tahun ini yaitu kultivasi kerang hijau (P. viridis) konsumsi. Berlokasi di kecamatan Teluk Betung Timur, hal ini dinilai tepat karena parameter lingkungan yang menunjang kehidupan P. viridis. Lokasi pembesaran P. viridis tidak jauh dari pemukiman penduduk pesisir (±500-600 m dari pemukiman). Kegiatan antropogenik penduduk pesisir juga penggunaan material plastik pada sistem pembesaran dikhawatirkan dapat menjadi sumber cemaran mikroplastik yang terdapat pada P. viridis. Penelitian ini bertujuan untuk mengetahui keberadaan dan karakteristik mikroplastik pada P. viridis juga membandingkan kelimpahan mikroplastik pada insang dan organ pencernaan. Pengambilan 30 P. viridis secara purposive sampling dengan ukuran homogen. Analisis mikroplastik dilakukan di laboratorium oseanografi kimia dan biologi mikro, FPIK, Universitas Pertanian Bogor. Destruksi jaringan P. viridis dengan menggunakan larutan KOH 10% perbandingan 1:3 (m/v) pada suhu 60 °C selama 24 jam lalu difiltrasi menggunakan filter paper whatman GF/A 1,6 µm. Mikroplastik tubuh kerang utuh yaitu 0,53±0,7 mgl/g. Organ insang lebih banyak ditemukan mikroplastik dibandingkan organ pencernaan (p<0,05). Bentuk fragmen paling banyak ditemukan di jaringan utuh dan organ pencernaan, sedangkan fiber banyak ditemukan di insang P. viridis. Warna biru dan ukuran <100 µm paling banyak ditemukan di jaringan utuh, insang maupun organ pencernaan P. viridis.
Pemetaan Luasan Hutan Mangrove Dengan Menggunakan Citra Satelit Di Pulau Mapur, Provinsi Kepulauan Riau Risandi Dwirama Putra; Herlanto Sihar Napitupulu; Aditya Hikmat Nugraha; Mario Putra Suhana; Abdul Rahman Ritonga; Tengku Ersti Yulika Sari
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.12294

Abstract

Mapping can be used as an alternative solution to find out the distribution map of the mangrove ecosystem by utilizing remote sensing technology and can provide value to the mangrove ecosystem. The purpose of this study was to map the distribution of mangrove ecosystems on Mapur Island. Sentinel-2b image is one of the satellite imageries had performance used to analyze the distribution of mangrove ecosystems. The mapping of the distribution of mangroves on Mapur Island shows that the mangrove ecosystem is distributed from the east to the northwest of Mapur Island. The northern part of Mapur Island has a sandy substrate classification that does not allow the growth of mangroves in the area. The distribution of mangrove classification results using Sentinel Citra-2b has a high pixel value classified of 88%, the comparison the accuracy of in situ data classification of 80%. The largest mangrove density is on Mapur Island, with a value of density of 156,729 ha. Pemetaan dapat dijadikan salah satu solusi alternatif untuk mengetahui peta sebaran luasan ekosistem mangrove dengan memanfaatkan teknologi penginderaan jauh dan dapat memberikan nilai luasan ekosistem mangrove. Tujuan dari penelitian ini adalah melakukan pemetaan sebaran luasan ekosistem mangrove di Pulau Mapur. Citra Sentinel-2b merupakan salah satu citra yang dapat digunakan untuk menganalisis sebaran luasan ekosistem mangrove. Hasil dari pemetaan sebaran mangrove di Pulau Mapur dapat dilihat bahwa ekosistem mangrove tersebar di bagian timur hingga barat laut Pulau Mapur. Bagian utara Pulau Mapur mempunyai tipe substrat yang berpasir sehingga tidak memungkinkan tumbuhan mangrove dapat tumbuh di daerah tersebut. Sebaran mangrove hasil klasifikasi dengan menggunakan Citra Sentinel-2b memiliki nilai piksel terklasifikasi hamper sempurna adalah 88%, sedangkan akurasi klasifikasi terhadap lapangan 80%. Kerapatan mangrove di Pulau Mapur yang paling luas dengan tingkat kerapatan padat dengan luas 156.729 ha. 
Ekplorasi Bakteri dari Air Laut yang Resisten Terhadap Pestisida Organofospat Khlorpirifos di Perairan Pantai Utara Jawa Tengah Chrisna Adhi Suryono; Agus Indarjo; Baskoro Rochaddi; Wilis Ari Setyati
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.13711

Abstract

Chlorpyrifos from agricultural activities eventually will flow to marine waters through rivers. This research was conducted to determine the resistance of bacteria from seawater of 100ppm Chlorpyrifos.  Three of the five bacterial strains was isolated from seawater from Brebes and Pati, Central Java were selected because they were resistant to the pesticide chlorpyrifos. Analysis of 16S rRNA gene sequences showed that the isolates belonged to the genus Virgibacillus spp. (2 strains) and Bacillus sp (1 strains). This bacterial strain has great potential ability to bioremediation of coastal waters of Brebes and Pati, Central Java from chlorpyrifos pesticide residues.  Khlorpifos dari hasil kegiatan pertanian lama kelamaan akan menuju ke perairan laut melalui aliran sungai.  Penelitian dilakukan untuk mengetahui resistensi baktrei dari air laut yang tahan terhadap 100ppm Khlorpirifos.  Tiga dari lima strain bakteri yang diisolasi dari air laut dari Brebes dan Pati Jawa Tengah dipilih karena resisten terhadap pestisida khlorpirifos.  Analisis sekuens gen 16S rRNA menunjukkan bahwa isolat termasuk dalam genus Virgibacillus sp. (2 strain) dan Bacillus sp (1 strain). Strain bakteri ini memiliki potensi penggunaan yang besar untuk bioremediasi perairan pesisir Brebes dan Pati Jawa Tengah dari residu pestisida klorpirifos.
Keragaman Genetik dan Filogenetik Kepiting Biola (Uca Spp.) di Pesisir Pantai Jailolo, Kabupaten Halmahera Barat Abdurrachman Baksir; Nebuchadnezzar Akbar; Firdaut Ismail
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.12185

Abstract

The types of crabs that inhabit coastal and mangrove areas are violin crabs (Uca spp.). The research genetic aspects is important to be able to explain the current status of crabs. The research location in the villages of Payo (geothermal water area) and Tuada (tourist sites). Sampling was done purposively, namely the mangrove area that received the flow of geothermal water sources (Payo Village = 4 samples) and the mangrove area that did not get any influence (Tuada Village = 2 samples). Amplification of Biola crab DNA (Uca Spp.) using primer jgLCO1490 and jgHCO2198 Sequences were analyzed with MEGA5 (Molecular Evolutionary Genetic Analysis) software, genetic distance, DnaSP 4.0 diversity of haplotype (Hd) and nucleotide diversity (π). and Network 4.6 haplotype distribution. Enviromental parameters collected include (temperature, pH land, pH water, salinity and substrate). The results environmental parameters show that differences values at two locations. Identification species crab found family Ocypodidae, genus Uca with species of perplexa, annulipes, crassipes and lactea. The results of genetic matching were found, similar to the results of morphological identification. Genetic diversity was found highly with nucleotides  and haplotype varitions. Phylogenetic reconstruction of Uca Spp crabs shows the kinship that occurs between species, although there is a gap (gap) between different species of location. Genetic distance and Fixation Index (Fst) analysis which also shows genetic proximity between species and strong genetic flow between species, despite different locations.  Jenis kepiting yang mendiami wilayah pesisir dan mangrove adalah kepiting biola (Uca spp.). Penelitian tentang aspek genetik begitu penting untuk dapat menjelaskan status kepiting saat ini. Lokasi penelitian di desa Payo (Daerah sumber air panas bumi) dan Tuada (Lokasi wisata). Sampling dilakukan secara purposive yaitu  area mangrove yang mendapatkan aliran sumber air panas bumi (Desa Payo = 4 sampel) dan tidak mendapatkan pengaruh (Desa Tuada =  2 sampel). Amplifikasi DNA kepiting Biola (Uca spp) menggunakan primer jgLCO1490 dan jgHCO2198 Sekuen dianalisis dengan software MEGA5 (Molecular Evolutionary Genetic Analysis), jarak genetik, DnaSP 4.0 keanekaragaman haplotype (Hd) dan keanekaragaman nukleotida (π) dan Network 4.6 distribusi haplotipe. Parameter lingkungan diukur meliputi (suhu, pH air, pH tanah, salinitas dan substrat). Hasil pengukuran parameter lingkungan memperlihatkan perbedaan nilai kedua lokasi. Identifikasi jenis kepiting ditemukan famili Ocypodidae, genus Uca dengan spesies  perplexa, annulipes, crassipes dan lactea.. Keragaman genetik sangat tinggi dengan jumlah nukleotida dan haplotipe yang bervariasi. Rekonstruksi filogenetik memperlihatkan kekerabatan terjadi antar spesies, meskipun terdapat adanya jarak (Gap) antar spesies yang berbeda lokasi. Analisis jarak genetik dan analisis Fixation Index (Fst) yang juga memperlihatkan adanya kedekatan genetik dan aliran genetik yang kuat antar spesies, meskipun berbeda lokasi.
Relationship of Cephalopods Orders Based on Morphological Characters Nova Mujiono; Putri Sapira Ibrahim
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.12246

Abstract

Biodiversity is vital in our daily life. As a maritime country, Indonesian waters harbor many valuable animals such as Cephalopoda. Indonesian waters are rich in various species of cephalopods. Several previous studies on Indonesian cephalopods have been published, from the fishery aspect, only a few studies from the biological aspect. Information on their diversity is still scarce. It may because the low rate of knowledge delivery from the expert to the peoples. Specimen collection is the primary source to conduct a systematic study. The present study aims to introduce the knowledge of the morphologically based taxonomy of Cephalopoda. Using the museum specimen in MZB, we made an introduction on how to distinguish the six orders of Cephalopoda. Only good preserved specimens used. Because this study intended to introduce the morphology, the specimens dissected to show the buccal mass and funnel parts. We selected one species as a representative of each known orders. The morphology was photographed using a camera for the large body parts and using a microscope for the small body parts. A phenogram based on the eleven comparative morphologies is constructed. Three main branches were identified. Nautilida was separated because of the presence of external shell and arm without suckers. Two other branches were mainly grouped based on on the number of arms. Nautiloidea is consist of only Nautilida, a group whose bearing external coiled shell and arm without suckers. The other five orders are classified in Coleoidea, a group whose internal reduced shell and arm with suckers.
Monitoring Bakteri Coliform pada Pasir Pantai dan Air Laut di Wisata Pantai Marina dan Pantai Baruna Wilis Ari Setyati; Delianis Pringgenies; Dony Bayu Putra Pamungkas; Chrisna Adhi Suryono
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.13775

Abstract

Marina and Baruna Beach are widely recognized as popular beach tourism destinations in Semarang. Its proximity to the main beach estuary causes them to significantly impact marine tourism quality. In addition, their exposure to waste may be a potential threat to biological pollution. Coliform and Escherichia coli are used as bioindicators to monitor the quality of marine tourism due to their high correlation to faecal contamination and pathogenic microbes. Samples collected were beach sand and seawater from Marina Beach, Baruna Beach and the estuary of Semarang Banjir Kanal Barat. Data were collected following the presumptive and confirmed test, followed by the conversion to MPN Table. Data obtained is combined with Government Regulations No. 22 of 2021 in Appendix VIII, specifically seawater quality standards for marine tourism. The results of this study reveal high contamination of coliform and E. coli in both beaches. Coliform result in the swimming zone at Marina Beach was 2800 MPN/100ml and at Baruna Beach was 16000 MPN/100ml. Meanwhile, Escherichia coli in the swimming zone area at Marina Beach was 400 MPN/100ml and at Baruna Beach was 1700 MPN/100ml. Overall, these results show that the contamination rate from both swimming zones is higher than the recommended seawater quality standard for marine tourism  Wisata Pantai Marina dan Pantai Baruna menjadi kawasan wisata pantai yang populer di Kota Semarang. Lokasinya yang berdekatan dengan muara sungai utama di Kota ini berdampak terhadap kualitas wisata pantai. Paparan limbah berpotensi menyebabkanpencemaran biologis. Monitoring terhadap bakteri coliform dan bakteri Escherichia coli dapat digunakan sebagai bioindikator kualitas wisata pantai, karena keberadaannya berkorelasi dengan cemaran feses dan mikroba patogen. Sampel berupa pasir pantai dan air laut diambil dari  lokasi Pantai Marina, Pantai Baruna, dan muara Sungai Banjir Kanal Barat Kota Semarang. Pengujian sampel dilaksanakan dengan presumtif test dan confirmed test, selanjutnya dikonversi dengan Tabel MPN. Data yang didapatkan akan dipadukan dengan PP Nomor 22 Tahun 2021 pada Lampiran VIII, yaitu baku mutu air laut untuk wisata bahari. Hasil penelitian menunjukkan tingginya kontaminasi bakteri coliform dan bakteri Escherichia coli dikedua pantai. Hasil coliform pada kawasan swimming zone pada Pantai Marina 2800 MPN/100ml dan Pantai Baruna 16000 MPN/100ml, serta hasil Escherichia coli pada kawasan swimming zone pada Pantai Marina 400 MPN/100ml dan Pantai Baruna 1700 MPN/100ml. Kawasan swimming zone pada wisata Pantai Marina dan Pantai Baruna mempunyai hasil yang melebihi baku mutu air laut untuk wisata bahari. 
Penilaian Pencemaran Logam Berat Cd, Pb, Cu, dan Zn pada Sedimen Permukaan Perairan Matras, Sungailiat, Bangka Mohammad Agung Nugraha; Aditya Pamungkas; Indra Ambalika Syari; Suci Puspita Sari; Umroh Umroh; Mu’alimah Hudatwi; Eva Utami; Irma Akhrianti; Agung Priyambada
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.12317

Abstract

Matras waters receive input of pollutants from tin mining activities. Heavy metals are toxic and carcinogenic to aquatic biota. Sediment is a carrier of heavy metal pollutants and can act as a “sink” and a “source”. Heavy metals in sediments can reflect the condition/quality of the aquatic system. The purpose of this study was to examine the contamination and ecological risk of heavy metals Cd, Pb, Cu, and Zn in the sediments of Matras waters, Sungailiat, Bangka Regency. Heavy metal test using atomic absorption spectrophotometer (AAS). The concentrations of heavy metals Cd, Pb, Cu, and Zn obtained ranged from 0.02-0.06 mg/kg (average 0.04 mg/kg), 0.12-0.18 mg/kg (mean- average 0.15 mg/kg), each station 0.01 mg/kg (mean 0.01 mg/kg), and 0.54-1.34 mg/kg (mean 0.92 mg/kg ). CF, I-Geo, PLI, and RI values for Cd, Pb, Cu, and Zn metals obtained in Matras water sediments showed low contamination levels (CF<1), not polluted (Igeo 0), not polluted (PLI < 1), and low ecological risk (RI < 150). The EF value obtained indicates the heavy metals Cd, Pb, Cu, and Zn in the Matras waters mainly receiving input from anthropogenic sources (EF value> 1.5). The low ecological risk status which is reinforced by the low values of CF, I-Geo, and PLI indicates that the negative potential of metals to biota is also low.  Perairan Matras menerima masukan bahan pencemar dari aktivitas penambangan timah. Logam berat bersifat toksik dan karsinogenik terhadap biota akuatik. Sedimen merupakan pembawa polutan logam berat dan dapat berperan sebagai “sink” and “source”. Logam berat pada sedimen dapat merefleksikan kondisi/ kualitas sistem akuatik. Tujuan penelitian ini untuk mengkaji kontaminasi dan resiko ekologi logam berat Cd, Pb, Cu, dan Zn pada sedimen Perairan Matras, Sungailiat, Kabupaten Bangka. Uji logam berat menggunakan metode spektrofotometer serapan atom (SSA). Konsentrasi logam berat Cd, Pb, Cu, dan Zn yang diperoleh berkisar antara 0,02-0,06 mg/kg (rata-rata 0,04 mg/kg), 0,12-0,18 mg/kg (rata-rata 0,15 mg/kg), setiap stasiun 0,01 mg/kg (rata-rata 0,01 mg/kg), dan 0,54-1,34 mg/kg (rata-rata 0,92 mg/kg). Nilai CF, I-Geo, PLI, dan RI untuk logam Cd, Pb, Cu, dan Zn yang diperoleh pada sedimen Perairan Matras menunjukkan tingkat kontaminasi rendah (CF<1), tidak tercemar (Igeo 0), tidak tercemar (PLI <1), dan resiko ekologi rendah (RI < 150). Nilai EF yang diperoleh mengindikasikan logam berat Cd, Pb, Cu, dan Zn perairan Matras utamanya mendapat masukan dari sumber antropogenik (nilai EF>1,5). Rendahnya status resiko ekologi yang diperkuat dengan rendahnya nilai CF, I-Geo, dan PLI menunjukkan potensi negatif logam terhadap biota juga rendah.
Pola Pertumbuhan Gastropoda Monetaria annulus di Teluk Doreri Yuventus Wale Wake; Roni Bawole; Emmanuel Manangkalangi; Luky Sembel; Ridwan Sala
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.12293

Abstract

Manokwari coastal waters are one of the coastal areas that experience very rapid development of development activities from year to year. This condition can disrupt the ecosystem and can also interfere with the growth of gastropods, especially Monetaria annulus. This research was conducted in three locations (Yenkarwar Beach, Nusmapi Island, and Tanjung Manggewa) for two months (October and November 2020). The purpose of this study was to describe the relationship between length and weight, as well as the growth pattern of the gastropod M. annulus in Doreri Bay. Data was collected using a square with a length of 100 m with a width adjusted to the width of the seagrass bed towards the sea. Especially for the location of the waters of Yenkarwar Beach, no individual M. annulus was found during the sampling. The results showed a relationship between length and weight at the locations of Nusmapi I. and Tanjung Manggewa, respectively, namely BT = 0.0017PC2.3883 and BT = 0.0005PC2.8188. The growth pattern of this species from both locations showed that the shell length increased faster than its body weight (negative allometric pattern). The value of b as a derivative of growth indicates better conditions in the sample at Tanjung Manggewa than on Nusmapi Island. This difference in value can be an illustration of the condition of the M. annulus habitat and therefore information on the relationship between length and weight of growth patterns becomes important in efforts to monitor population conditions and their preservation in natural habitats.  Perairan pesisir Manokwari merupakan salah satu wilayah pesisir yang mengalami perkembangan kegiatan pembangunan yang sangat pesat dari tahun ke tahun. Kondisi ini dapat mengganggu ekosistem dan juga dapat mengganggu pertumbuhan gastropoda, khususnya  Monetaria annulus. Penelitian ini dilakukan di tiga lokasi (perairan Pantai Yenkarwar, Pulau Nusmapi, dan Tanjung Manggewa) selama dua bulan (Oktober dan November 2020). Tujuan dari penelitian ini yaitu untuk mendeskripsikan hubungan panjang dan berat, serta pola pertumbuhan gastropoda M. annulus di Teluk Doreri. Pengumpulan data dilakukan dengan menggunakan kuadrat dengan panjang 100 m dengan lebar yang disesuaikan dengan lebar hamparan lamun ke arah laut. Khusus untuk lokasi perairan Pantai Yenkarwar tidak ditemukan individu M. annulus selama sampling dilakukan. Hasil penelitian menunjukkan hubungan panjang dan berat pada lokasi P. Nusmapi dan Tanjung Manggewa secara berturut-turut, yaitu BT = 0,0017PC2,3883 dan BT = 0,0005PC2,8188. Pola pertumbuhan spesies ini dari kedua lokasi menunjukkan pertambahan panjang cangkang lebih cepat dibandingkan berat tubuhnya (pola alometrik negatif). Nilai b sebagai derivat dari pertumbuhan menunjukkan kondisi yang lebih baik pada sampel di lokasi Tanjung Manggewa dibandingkan Pulau Nusmapi. Perbedaan nilai ini bisa menjadi gambaran kondisi habitat M. annulus dan oleh karena itu informasi mengenai hubungan panjang dan berat pola pertumbuhan menjadi penting dalam upaya pemantauan kondisi populasi dan pelestariannya di habitat alami. 
Perubahan Garis Pantai dan Dampaknya Terhadap Banjir Rob di Kecamatan Pekalongan Utara, Kota Pekalongan, Privinsi Jawa Tengah Sugeng Widada; Aris Ismanto; Ika Bagus Priambodo; Hendry Siagian
Jurnal Kelautan Tropis Vol 25, No 1 (2022): JURNAL KELAUTAN TROPIS
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jkt.v25i1.13843

Abstract

The coastal area of Pekalongan City, especially in the North Pekalongan District which includes Kandang Panjang Village, Panjang Wetan Village, Krapak Lor Village and Degayu Village is often inundated by tidal floods which are increasingly widespread from year to year. This incident resulted in the destruction of infrastructure and inundation of land so that it greatly disrupted residential areas, economic areas, cultivated land and community activities. The river channel near the estuary and coastal abrasion is the entry point for sea water which causes the tidal flood. This research were to determine the process of abrasion and accretion that causes changes in the coastline which results in the destruction of the coastal embankment and eventually becomes the channel for sea water to flow to the mainland. The results of this study are expected to be a consideration in tidal flood protection by preventing coastal abrasion at crucial points. The mathematical simulation method was used in this study to obtain shoreline changes based on the concept of longshore sediment transport as presented in the integrated littoral processes and coastline kinetics modeling module by Mike 21. Significant wave heights and periods are calculated from wind data using the Sverdrup Munk Bretchneider (SMB) method. The coastline used in the model simulation is the result of digitizing photos taken through ESRI's GeoEYE. Sediment data was obtained by taking samples in the field and granulometric analysis in the laboratory. The results showed that in the west monsoon the largest accretion of 25 m occurred at the west of Slamaran Beach’s Jetty and the largest abrasion was of 10.23 m to the west of the the Banger River’s jetty. Meanwhile, in the east monsoon, the highest accretion was 15.2m in the east of the Loji River’s Jetty and the largest abrasion was 13.5m at Pasir Kencana Beach. Locations of abrasion as a channel for sea water to flow inland include the Pasir Kencana Beach area, east of the Slamaran Beach’s Jetty and around the Banger River’s Jetty Wilayak pesisir Kota Pekalongan, khususnya di wilayah Kecamatan Pekalongan Utara yang meliputi Kelurahan Kandang Panjang, Kelurahan Panjang Wetan, Kelurahan Krapak Lor dan Kelurahan Degayu telah mengalami banjir rob yang semakin luas dari tahun ke tahun. Kejadian ini berdampak pada rusaknya infrastruktur dan tergenangnya lahan sehingga sangat mengganggu wilayah pemukiman, kawasan perekonomian, lahan budidaya serta aktivitas masyarakat. Alur sungai di dekat muara dan abrasi pantai merupakan jalur masuknya air laut yang mengakibatkan banjir rob tersebut. Penelitian ini bertujuan untuk mengetahui proses abrasi dan akresi yang menyebabkan perubahan garis pantai yang berakibat pada rusaknya tanggul pantai dan akhirnya menjadi pintu masuknya air laut ke daratan. Hasil penelitian ini daharapkan dapat menjadi pertimbangan dalam penanggungan banjir rob dengan mencegah abrasi pantai pada titik-titik yang krusial. Metode yang digunakan dalam penelitian ini adalah metode simulasi matematis untuk mendapatkan perubahan garis pantai berdasarkan konsep transport sedimen sejajar pantai (longshore transport) sebagaimana disampaikan dalam modul integrated littoral processes and coastline kinetics modelling by Mike 21. Tinggi gelombang signifikan dan periodenya dihitung dengan metode Sverdrup Munk Bretchneider (SMB) dari data angin. Garis pantai yang digunakan pada simulasi model merupakan hasil digitasi foto yang dicuplik melalui GeoEYE ESRI. Sedangkan data sedimen diperoleh dengan pengambulan sampel di lapangan dan analisis granulometri di laboratorium. Hasil penelitian menujukan pada musim barat akresi terbesar sebesar 25 m terjadi di sebelah barat jetty Pantai Slamaran dan abrasi terbesar adalah sebesar 10.23m di sebelah barat tanggul pantai-jetty barat Sungai Banger. Sedangkan pada musim timur akresi tertinggi adalah sebesar 15,2m terjadi di sebelah timur Jetty Sungai Loji dan abrasi terbesar 13.5m terjadi di Pantai Pasir Kencana. Lokasi abrasi yang menjadi alur mengalirnya air laut ke daratan diantaranya adalah area Pantai Pasir Kencana, sebelah timur Jetty Pantai Slamaran dan di sekitar Jetty Sungai Banger hingga Pantai Degayu.