I Dewa Nym. Nurweda P.,
Program Studi Ilmu Kelautan, Fakultas Kelautan Dan Perikanan, Universitas Udayana Kampus Unud Jimbaran, Badung, Bali, Indonesia

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STUDY OF OCEAN CIRCULATION IN INDONESIAN ARCHIPELAGO SEA USING THREE DIMENSIONAL OCEAN MODEL I Dewa Nym. Nurweda P.,; Takahiro Osawa; I Wayan Arthana
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 4 No 2
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The Regional Ocean Modeling System (ROMS) was used to simulate the Indonesian Archipelago Sea current and temperature with two different vertical mixing schemes. One corresponds to the newly developed K-Profile Parameterization (KPP) scheme and the other is adapted from the stability frequency of Brunt-Vaisala Frequency mixing (BVF). It is found that, both of schemes produce reasonably realistic sea surface temperature (SST); however, the root mean square error (RMSE) values from the BVF vertical mixing were less than the KPP vertical mixing. The RMSE values from the BVF vertical mixing at northwest and southeast monsoons can be reduced down to 5.1607E-01 0C and 5.7639E-01 0C respectively. These validation results reveal that accuracy of the BVF vertical mixing is better than the KPP vertical mixing.The model results based on the BVF vertical mixing scheme show that the direction of Java Sea, Karimata and Sunda Straits surface current are strongly affected by the zonal wind system. The direction of surface current was change following the monsoonal wind system. On the other hand, the Makasar Strait surface current tend to flow southward throughout the year with annual variations in transport are related dynamically to the monsoon winds. These southward surface currents are known as Indonesian Through Flow (ITF) and it is governed by strong pressure gradient from the Pacific to the Indian Oceans. The signals of El Nino 2002 event also can be detected by the model results. It recognized that the strong Equatorial Counter Current flows to eastward to the central part of the Pacific Ocean. The Makasar Strait surface current was stronger than usual but the Karimata Strait surface current was weaker during this period.
Recent Invasion of the Endemic Banggai Cardinalfish, Pterapogon kauderni at The Strait of Bali: Assessment of the Habitat Type and Population Structure I Nyoman Giri Putra; I Dewa Nyoman Nurweda Putra
ILMU KELAUTAN: Indonesian Journal of Marine Sciences Vol 24, No 1 (2019): Ilmu Kelautan
Publisher : Marine Science Department Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (829.495 KB) | DOI: 10.14710/ik.ijms.24.1.15-22

Abstract

The demands of marine organisms for the aquarium trade are remain high and seems continue to increase. Consequently, many of marine organisms has been spread out from its natural habitat as in the case of endemic Banggai cardinalfish, (Pterapogon kauderni). That has invaded “new” habitat since it being trade in 1995. In recent years, a small populations of P. kauderni is known to be exist in a narrow bay near the Gilimanuk harbor, Bali. An underwater visual fish census survey was conducted on June 2018 to estimate the habitat types and densities of P. kauderni.  Additionally, 23 specimens of P. kauderni were collected randomly in order to assess biological parameters such as the length-weight relationship. We successfully recorded 30 groups of P. kauderni that inhabit a shallow areas with a depth range between 0.5m to 2m. Of these, more than 90% of the groups were found to be associated with sea urchin (Diadema sp.) while the rest were found to live together with branching coral (Acropora sp.) and branching sponge (Ptylocaulis sp.). Total number of fish observed during the survey were 381 individuals. The fish density is 0.76 individu.m-2. Length-weight relationship showed that P. kauderni exhibit is negative allometry (b<3) which mean that the increase in length is faster than the weight gain. Interestingly, from the 23 specimens collected, none of these were sexually mature (SL<41 mm) which may indicated that the population of P. kauderni in Bali are under serious threats of exploitation.     
Aplikasi Penghitungan Gross Primary Production dari Data Penginderaan Jauh Komang Gede Kurniadi; I Putu Agung Bayupati; I Dewa Nyoman Nurweda Putra
Lontar Komputer : Jurnal Ilmiah Teknologi Informasi Vol. 7, No. 1 April 2016
Publisher : Institute for Research and Community Services, Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (539.3 KB) | DOI: 10.24843/LKJITI.2016.v07.i01.p04

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Calculation of Gross Primary Production that utilize remote sensing data is can be done on commercial remote sensing software by manual method. The commercial remote sensing software does not provides a specific feature that allow the user to do the Gross Primary Production calculation. This research is aimed to to build a remote sensing software that can be specifically used to do the Gross Primary Production calculation for Denpasar area. This software accepts remote sensing data as an input, such as satellite image from Landsat 8 OLI and TIRS and metadata file. The formulas and supporting data that required on the Gross Primary Production calculation are implemented on software in order to make an automatic image processing software. There also some additional feature on this software such as automatic data parsing from metadata file, cropping, masking and zoom that could help user to do the Gross Primary Production calculation. The developed software is able to produce information such as Gross Primary Production value that depicted by a figure with color segmentation, area of the segments and mean, minimum and maximum value of the Gross Primary Production.
Estimasi Potensi Produksi Rumput Laut di Perairan Nusa Penida Menggunakan Citra Landsat 8 Made Pande Darmawan; I Dewa Nyoman Nurweda Putra; Widiastuti Karim
Journal of Marine Research and Technology Vol 2 No 2 (2019): AGUSTUS 2019
Publisher : Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (668.116 KB) | DOI: 10.24843/JMRT.2019.v02.i02.p09

Abstract

Seaweed is a macroalgae that has many benefits for humans, therefore to meet human needs, seaweed is developed by cultivation. One place for seaweed cultivation in Bali Province is in Nusa Penida Sub-district, which is a water conservation area in accordance with the Decree of the Minister of Marine and Fisheries / KEPMEN KKP No. 24 of 2014. The development of these areas into tourist destinations and the number of seaweed pests and diseases has caused reduced number of farmers who grow seaweed. The data used was secondary data obtained from Department of Marine and Fisheries of Bali Province and field data was taken in February 2018. Landsat 8 imagery that has been corrected by Top of Atmosphere then lyzenga algorithm was included for correction of water columns and then classified the maximum likelihood with coordinate training area, which only classified seaweed classes. The area of seaweed in Nusa Penida using Landsat 8 imagery on February 2018 acquisition was obtained at 69.48 hectares with an accuracy rate of total seaweed of 85.34% and an accuracy of 63.22%. Whereas the estimated results that could potentially be produced in February 2018 were 89,321 tons.
Skrining Fitokimia Ekstrak Daun Mangrove Rhizophora mucronata dan Rhizophora apiculata yang Dikoleksi dari Kawasan Mangrove Desa Tuban, Bali Alanis Ismi Akasia; I Dewa Nyoman Nurweda Putra; I Nyoman Giri Putra
Journal of Marine Research and Technology Vol 4 No 1 (2021): FEBRUARI 2021
Publisher : Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JMRT.2021.v04.i01.p03

Abstract

The content of secondary metabolite compounds in marine plants, especially mangrove has a certain bioactivity. Therefore, this study was aims to determine the content of secondary metabolites in the mangrove leaf extract of Rhizophora apiculata and Rhizophora mucronata. This study was conducted on January-April 2020. Sampling locations were carried out in the Mangrove Conservation Area of Tuban Village, Bali. In this study, samples were collected in the form of old leaves. The samples were taken in three sites and in each sites, 500 gr of leaves were collected randomly for each species. Therefore, in total we have 1.5 kg of leaves for each species. Samples are then extracted and tested to determine the content of secondary metabolites. The results showed the content of secondary metabolites in the leaves of R. apiculata mangrove were phenols, alkaloids, flavonoids, tannins, saponins, steroids while R. mucronata contained phenols, flavonoids, tannins, saponins, terpenoids.
Studi Pola Pergerakan dan Lama Waktu Tinggal Partikel di Kawasan Perairan Nusa Penida, Bali Ida Bagus Andika Putra; I Gede Hendrawan; I Dewa Nyoman Nurweda Putra
Journal of Marine Research and Technology Vol 3 No 2 (2020): AGUSTUS 2020
Publisher : Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JMRT.2020.v03.i02.p03

Abstract

Nusa Penida is a tourist destination, located on the east of Bali, which is well-known of its natural panoramic. Increasing tourism sector in Nusa Penida may have positive impacts, but it can also have negative impacts, such as an increase in the amount of waste and other pollutants, which will eventually be discharged into the waters. High concentration of pollutant can reduce water quality. The water quality in the sea can be control by the residence time, and the sea current would spread waste in the ocean. Based on these problems, it is important to conduct a research on the movement and length of particle residence in the waters of Nusa Penida, Bali. This research was carried out in January 2019, to represent the rainy season conditions, and in July 2019, to represent the dry season conditions. The residence time was calculated using a numerical modeling method namely Finite Volume Coastal Ocean Model (FVCOM). Based on the simulation results, the residence time of particle in the dry and rainy season has a similar pattern. Areas with fast residence times are found in the eastern Nusa Penida waters, while areas with weak residence times are found in the Toyapakeh strait. Generally, Nusa Penida waters have a relatively short residence time, 1- 4 hours.
Pemetaan Habitat Bentik Menggunakan Citra Sentinel-2A dan Unmanned Aerial Vehicle (UAV) di Perairan Pemuteran, Bali Elvita Rahmani; I Wayan Gede Astawa Karang; I Dewa Nyoman Nurweda Putra
Journal of Marine Research and Technology Vol 5 No 1 (2022): FEBRUARI 2022
Publisher : Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JMRT.2022.v05.i01.p06

Abstract

The benthic habitat has a huge ecological and economic role in the sustainability of the coastal environment and is vulnerable to change. The importance of the existence of the benthic habitat requires identification and monitoring of the habitat's existence and status. One of the technologies that can be utilized is remote sensing technology, which is able to provide solutions to the limitations of conventional methods, such as time that is relatively long, costly, and difficult to reach remote and risky areas. Selection of sensing vehicles takes into consideration the needs and desired qualities because the sensors brought in to detect habitats have different abilities. Sentinel-2A imagery is an open-source satellite with a 10 m spatial resolution capability, while the image from Unmanned Aerial Vehicle (UAV) has a high spatial resolution of up to 1 cm per pixsel depending on flight level. The purpose of this study is to identify the degree of accuracy and the scattered conditions of the benthic habitat by the sentinel-2A imagery and the UAV imagery in mapping the benthic habitat in the shallow waters of Pemuteran. The two images for classification use classification based objects and accuracy tests using the confusion matrix method. Based on field observations, five kinds of habitat composition with vast dead corals, dead coral, rubble, biorock, sand, and stone sand are 13.63 ha, 1.45 ha, 0.87 ha, 6.05 ha, and 1.67 ha on the sentinel-2A imagery and 12.86 ha, 1.54 ha, 0.18 ha, 7.32 ha, and 1.76 ha on the UAV imagery. The Sentinel-2a's imagery capability in mapping the benthic habitat is adopted by 73.95%, whereas the UAV imagery is 81.51%. The value of accuracy obtained in the study shows the use of remote sensing data using both imagery can be used for the mapping of habitat benthic.
Kajian Pengembangan Budidaya Ikan Kerapu dan Rumput Laut di Perairan Timur Pulau Serangan Septi Novita Sari; I Dewa Nyoman Nurweda; Elok Faiqoh; I Nyoman Giri Putra
Journal of Marine Research and Technology Vol 2 No 2 (2019): AGUSTUS 2019
Publisher : Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (281.698 KB) | DOI: 10.24843/JMRT.2019.v02.i02.p01

Abstract

Grouper and seaweed are Indonesian fishery export commodities. One of the regions contributing to the production of groupers and seaweed is the northern waters of Serangan, Bali. However, over the past few years, the production of groupers and seaweed in the northern waters of Serangan has decreased. With these conditions, an effort is needed to increase the production of grouper and seaweed more optimally. One of these efforts is the expansion of area for the development of grouper and seaweed aquaculture in other places, because at present in the northern waters of the attack the condition is not conducive due to the dense sea traffic activities. One place to be used as a place to develop grouper and seaweed aquaculture is the eastern waters of Serangan because it is not too busy with sea traffic activities in the region. To see the potential of the eastern waters of Serangan, it is necessary to study the physical, chemical and biological parameters of these waters. Through the study of these water parameters, it aims to find suitable locations for the development of grouper aquaculture and the development of seaweed cultivation in terms of water quality. The results showed that, in the eastern and northern waters of Serangan, are 60% and 65.21% respectively of the condition of the waters is quite suitable to support the development of grouper aquaculture. Whereas, in the eastern waters of Serangan Island, at the north and central parts, about 64.8% of the condition of the waters is quite appropriate to support the development of seaweed cultivation. Suggestions that can be given through this research is that an economic and socio-cultural review is needed in the eastern waters area of Serangan as a place for developing grouper and seaweed aquaculture.
Pemetaan Perubahan Penggunaan Lahan Wilayah Pesisir Kecamatan Rungkut, Kota Surabaya, Tahun 2013 dan 2019 Diah Pertami; I Wayan Nuarsa; I Dewa Nyoman Nurweda Putra
Journal of Marine Research and Technology Vol 5 No 1 (2022): FEBRUARI 2022
Publisher : Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JMRT.2022.v05.i01.p03

Abstract

The coastal area is a meeting space between land and sea that is easy to change temporally and spatially. The changes were triggered due to an increase in population and community activities such as industry, housing, ports, cultivation, transportation, farms, agriculture, tourism, and so on centered in the coastal area and become the center of Indonesia's economy. Remote sensing technology is one of the right ways for monitoring activities in the near term. This research aims to map the change of coastal land use in Rungkut district, Surabaya, in 2013 and 2019 using high-resolution satellite imagery of SPOT imagery. The method of classification of coastal land use two types of supervised classification, namely Minimum Distance and Maximum Likelihood. Land use class obtained in this study as many as six classes, namely mangrove, settlement, pond, green open space, the body of water, and industry. The results showed that using two different algorithms gave a difference in classification results. The largest land-use change from classification with Minimum Distance method is in mangrove and body of water with +231,80 and –230,89 ha, while the classification result with the method of Maximum Likelihood the change of the largest land use is in mangrove class and ponds respectively +202,41 and –210,89 ha. Accuracy test using error matrix obtained by 85,50% with kappa coefficient 0,78 on the classification result of coastal land use using Minimum Distance algorithm and for Maximum Likelihood algorithm obtained accuracy of 89% with Kappa coefficient is 0,84. It is demonstrated that by using the algorithm, Maximum Likelihood accuracy on the land use map is very good.
Struktur Vegetasi Mangrove berdasarkan Karakteristik Substrat di Pantai Karang Sewu, Gilimanuk Bali Pande Komang Egar Prihandana; I Dewa Nyoman Nurweda Putra; Gede Surya Indrawan
Journal of Marine Research and Technology Vol 4 No 1 (2021): FEBRUARI 2021
Publisher : Department of Marine Sciences, Faculty of Marine Science and Fisheries, Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/JMRT.2021.v04.i01.p05

Abstract

Karang Sewu Beach is one of the areas in the West Bali National Park (TNBB) which has a natural mangrove ecosystem. One of parameters affecting mangrove growth is substrate. This research aims to determine the vegetation structure, substrate characteristics, and different vegetation groups of mangroves based on its substrate characteristics in Karang Sewu Beach. This study collected the data on vegetation structure using a plotted line method with 2x2, 5x5, 10x10 and 20x20 meters transects. Substrate texture was analyzed using a pipette method while total organic material was analyzed using the Loss on Ignition (LOI) method. Mangrove vegetation was categorized based on substrate characteristics using the descriptive quantitative method. Results showed there were nine species of mangrove found in Karang Sewu Beach, namely Ceriops tagal, Sonneratia alba, S. caseolaris, Rhizophora apiculata, R. mucronata, R. stylosa, R. lamarckii, Lumnitzera racemosa, and Avicennia marina. INP in the first station was dominated by R. apiculata for tree levels (152,88 %), pole (174,24 %), sapling (139,04 %), and seedling (111,48 %). R. lamarckii dominated the second station with a tree level value of 226,94 % while C. tagal dominated for pole level (220,82 %), sapling (243,65 %), and seedling (182,94 %). INP in the third stasion was dominated by C. tagal for pole level (103,68 %), sapling (98,77 %) and seedling (95,51 %). Mangrove substrate in Karang Sewu Beach was characterized as having a sand like texture, dusty loam, sandy loam, loamy sand, and sandy clay with moderate organic matter (2.44 %) to low (0.79 %). Mangrove vegetation grouping based on substrate characteristics in Karang Sewu Beach was different in general. A. marina is found in the middle zone, where this species is usually found in the front zone.
Co-Authors A. A. Md. Ananda Putra Suardana Alanis Ismi Akasia Anak Agung Kompiang Oka Sudana Ayu Wirdiani Brasika, Ida Bagus Mandhara Dewa Ayu Mira Prabaswari Diah Pertami Dzaki Adilla Razaan Dzaki Adilla Razaan Elok Faiqoh Eloq Faiqoh Elvita Rahmani G M Arya Sasmita Gede Surya Indrawan Gede Surya Indrawan Gede Yuda Kamajaya Hendra Yoga Pratama Herlambang Aulia Rachman I Dewa Gede Alit Sujana I Gede Hendrawan I Gusti Bagus Sila Dharma I Gusti Ngurah Putra Dirgayusa I Gusti Putu Ary Wedangga I Gusti Putu Bayu Arri Putra I Kade Alfian Kusuma Wirayuda I Kadek Vidyananda S Rahadiarta I Ketut Adi Purnawan I Komang Agus Parnata I Made Putra Kresnabayu I Made Satya Prayoga I Nyoman Januarta Triska Putra I Putu Agung Bayupati I Putu Yogi Darmendra I Wayan Arthana I Wayan Gede Astawa Karang I Wayan Nuarsa I Wayan Nuarsa Ida Bagus Andika Putra Ida Bagus Kade Putra Susila IGA Ayu Mirah Indraiswari Kadek Ayun Wardimas Karina Santoso Kholifatul Aziz Komang Gede Kurniadi Kuncoro Teguh Setiawan Luh Putu Puspita Dewanti Made Pande Darmawan Mark Johannes Wiggers Ngurah Padang Adnyana Ni Kadek Ayu Dwi Lestari Ni Luh Eta Yuspita Ni Luh Putu Ria Puspitha Ni Made Pitria Menala Saputri Ni Putu Ayu Aryanti Ni Wayan Ayu Astini Sari Ni Wayan Sintaningsih Nur Asni Puspita Sari Pande Komang Egar Prihandana Priscilla Princessa Amalo Putra, I Nyoman Giri Putu Hernanda Krishna Ariszandy Putu Natalia Sarasvati Putu Wira Buana Ramadhani Ahmad Rowand Danny Sebastian Adinegoro Septi Novita Sari Suprapto, Nyoman Arto Syifa’ul Qolbiyatun Nisa Takahiro Osawa Takahiro Osawa Tania Maria Octarina Taradhita, Dewa Ayu Nadia Valenthio Sidauruk Veranita Lamrotua Sihombing Widiastuti Karim Widiastuti Karim Widiastuti Widiastuti Widiastuti Widiastuti Yasa, Putu Kumara Yulianto Suteja