scholarly journals ANALYSIS OF POTENTIAL FISHING ZONES IN COASTAL WATERS: A CASE STUDY OF NIAS ISLAND WATERS

Author(s):  
Anang Dwi Purwanto ◽  
Teguh Prayogo ◽  
Sartono Marpaung ◽  
Argo Galih Suhada

The need for information on potential fishing zones based on remote sensing satellite data (ZPPI) in coastal waters is increasing. This study aims to create an information model of such zones in coastal waters (coastal ZPPI). The image data used include GHRSST, SNPP-VIIRS and MODIS-Aqua images acquired from September 1st-30th, 2018 and September 1st-30th, 2019, together with other supporting data. The coastal ZPPI information is based on the results of thermal front SST detection and overlaying this with chlorophyll-a. The method of determining the thermal front sea surface temperature (SST) used Single Image Edge Detection (SIED). The chlorophyll-a range used was in the mesotropic area (0.2-0.5 mg/m3). Coastal ZPPI coordinates were determined using the polygon centre of mass, while the coastal ZPPI information generated was only for coastal areas with a radius of between 4-12 nautical miles and was divided into two criteria, namely High Potential (HP) and Low Potential (LP). The results show that the coastal ZPPI models were suitable to determine fishing locations around Nias Island. The percentage of coastal ZPPI information generated was around 90% information monthly. In September 2018, 27 days of information were produced, consisting of 11 HP sets of coastal ZPPI information and 16 sets of LP information, while in September 2019 it was possible to produce 29 days of such information, comprising 11 sets of HP coastal ZPPI information and 18 LP sets. The use of SST parameters of GHRSST images and the addition of chlorophyll-a parameters to MODIS-Aqua images are very effective and efficient ways of supporting the provision of coastal ZPPI information in the waters of Nias Island and its surroundings.

Author(s):  
Rossi Hamzah ◽  
Sartono Marpaung ◽  
Teguh Prayogo

Information points coordinate of potential fishing zones (PFZ) is required by user that to be more effective in conducting fishing operation. The results of thermal front detection using single image edge detection (SIED) asshape contour lines. This research aims to determine points coordinate for potential fishing zone based on detection of thermal fronts sea surface temperatures.To determine point coordinate performed segmentation on detection result according to size fishnet grid. Contour line contained in each grid is a polygon shape.Centroid of each polygon is point coordinate of PFZ. The result of sea surface temperature data processing from Terra/Aqua MODIS and Suomi NPP VIIRS satellitesindicates that method of determination the centroid of polygon is very effective in determining the point coordinate of PFZ. Using that method the processing stages of satellite data to be faster, more efficient and practical due to the information of PFZ is already as points coordinate.Abstrak Informasi titik koordinat zona potensi penangkapan ikan (ZPPI) sangat diperlukan oleh pengguna agar lebih efektif dalam melakukan operasi penangkapan ikan. Hasil deteksi termal front menggunakan metode Single Image Edge Detection (SIED) dalam bentuk garis kontur. Penelitian ini bertujuan untuk menentukan titik koordinat ZPPI berdasarkan hasil deteksi termal front suhu permukaan laut. Untuk menentukan titik koordinat dilakukan segmentasi hasil deteksi sesuai ukuran fishnet grid. Garis kontur yang terdapat dalam setiap grid merupakan bentuk poligon. Pusat geometri dari setiap poligon merupakan titik koordinat ZPPI. Hasil pengolahan data suhu permukaan laut dari satelit Terra/Aqua MODIS dan Suomi NPP VIIRS menunjukkan bahwa metode penentuan pusat geometri poligon sangat efektif dalam menentukan titik koordinat ZPPI. Dengan menggunakan metode tersebut tahap pengolahan data satelit menjadi lebih cepat, efisien dan lebih praktis karena informasi ZPPI sudah dalam bentuk titik koordinat.


2020 ◽  
Vol 4 (1) ◽  
pp. 48-64
Author(s):  
Ridla Kumara Hadi ◽  
Rudy Hartanto ◽  
Silmi Fauziati

Metode yang digunakan untuk penentuan thermal fronts adalah algoritme Single Image Edge Detection dengan threshold statis 0,5 yang didapatkan dari penelitian terdahulu. Kekurangan dari metode threshold statis adalah tingginya bias akurasi hasil deteksi dikarenakan lebih banyaknya hasil deteksi negatif tervalidasi dibandingkan deteksi front murni yang tervalidasi. Penelitian yang diusulkan bertujuan untuk meningkatkan performa metode deteksi daerah potensi ikan. Peningkatan performa deteksi thermal front dapat dilakukan dengan mencari nilai threshold optimal yang sesuai untuk masing-masing citra. Threshold adaptif didapatkan dari hasil analisis histogram pada setiap citra greyscale yang diproses. Untuk mendapatkan nilai threshold optimal dipilih Algoritme Otsu dengan pertimbangan proses cepat dan ketepatan hasil menengah. Penyesuaian metode dibutuhkan karena sifat dasar data SST yang dikonversi menjadi raster. Modifikasi metode Otsu dilakukan pada perhitungan nilai threshold optimal dengan rentang intensitas greyscale 1-254. Pemurnian front menggunakan pendekatan Geodesic Buffering dengan jarak maksimal 10 kilometer untuk mengatasi pergeseran front akibat noise suppression. Penelitian telah dilakukan dan menghasilkan metode deteksi daerah potensi ikan dengan performa recall yang lebih tinggi 25,42% dibandingkan metode threshold statis. Nilai recall lebih tinggi membuktikan bahwa metode yang diusulkan mampu menghasilkan lebih banyak hasil deteksi front murni yang lokasinya tervalidasi dengan data aktual penangkapan ikan.


2019 ◽  
Vol 8 (4) ◽  
pp. 416-423
Author(s):  
Trinugroho Trinugroho ◽  
Alfi Satriadi ◽  
Muslim Muslim

Thermal front didefinisikan sebagai pertemuan antara dua masa air dengan karakteristik suhu yang berbeda sehingga membentuk gradien suhu. Thermal front merupakan salah satu proses oseanografi penting yang dapat mempengaruhi kondisi fisik, kimia, maupun biologi di laut. Tujuan dari penelitian ini adalah untuk mengetahui sebaran thermal front musiman di perairan Selat Madura, Jawa Timur. Deteksi thermal front dilakukan pada lapisan permukaan laut dengan menggunakan citra AquaMODIS untuk suhu permukaan laut. Citra AquaMODIS yang digunakan memiliki resolusi spasial sebesar 1 km x 1 km dan resolusi temporal selama satu hari. Metode yang digunakan untuk mendeteksi fenomena ini adalah metode Single Image Edge Detection (SIED) yang diperkenalkan oleh Cayula dan Cornilon pada tahun 1992. Metode ini menggunakan prinsip deteksi tepi piksel yang mempertimbangkan nilai gradien suhu dan pola arah dari piksel yang memiliki gradien suhu. Hasil yang diperoleh berupa sebaran spasial dan temporal fenomena thermal front di perairan Selat Madura. Sebaran temporal berdasarkan komposit harian dalam satu musim selama empat tahun dari tahun 2012 – 2016. Rata – rata kejadian thermal front tiap musim sebanyak 446 kali pada musim barat, 1893 kali pada musim peralihan I, 1038 kali pada musim timur, dan 2375 kali pada musim peralihan II. Penyebab utama kejadian front di perairan Selat Madura adalah akibat adanya arus eddy dan masukan masa air laut dari wilayah timur Selat Madura. Thermal front defined as an ecounter of two water masses which has different temperature (thermal) characteristics and create a thermal gradient. Thermal front is one of the most important oceanographic proceses that can make a significant impact to physical, chemical, and biological process in the ocean. The aim of this research is to understand seasonal thermal front distribution in Madura Strait, East Java. Thermal front was detected in the surface layer of water, using AquaMODIS for Sea Surface Temperature (SST). AquaMODIS image which used in this research has 1 km x 1 km spatial resolution and one day (24 hours) temporal resolution. Front detection in this research is using Single Image Edge Detection by Cayula Cornilon (1992). This method is using edge detection of pixel, considering the value of thermal gradient and pattern of the pixel edge. The result of this research is spatial and temporal distribution of thermal front in Madura Strait. Temporal distribution are based on composite result of daily front detection in seasonal range for four years from 2012-2016. Seasonal average of front occurence is 446 times in western season, 1893 times in Transition I, 1038 times in eastern season and 2375 times in Transition II. The main cause of front in Madura strait is eddy current and water masses ecounter from eastern area of Madura.


2020 ◽  
Vol 3 (2) ◽  
pp. 205-215
Author(s):  
Ridwan Ariyo Nugroho ◽  
Mega L. Syamsudin ◽  
Yuli Andriani ◽  
Izza Mahdiana Apriliani

Penelitian ini bertujuan untuk mengetahui lokasi dan waktu terjadinya thermal front pada perairan Selat Bali serta pengaruhnya terhadap penentuan daerah penangkapan ikan pelagis. Metode yang digunakan adalah Single Image Edge Detection (SIED) dengan menggunakan data Suhu Permukaan Laut (SPL) yang diakses dari satelit MODIS dengan sensor Aqua (MODIS-Aqua), lokasi penangkapan tahun 2013 sampai 2015 diperoleh dari pelabuhan perikanan Pengambengan, dan arus geostropik yang diambil dari European Centre for Medium-Range Weather Forecasts (ECMWF). Identifikasi thermal front dari data citra raster SPL menggunakan algoritma SIED kemudian dianalisis secara deskriptif dengan pendekatan spasial dan temporal. Hasil penelitian menunjukan thermal front yang terbentuk bersifat sementara pada kisaran harian hingga mingguan dengan kekuatan lemah dan kuat. Thermal front terbentuk pada musim barat dimulai dari arah barat selatan Selat Bali. Musim peralihan 1 terbentuk di selatan Selat Bali. Masuk ke musim timur dan peralihan 2 terbentuknya thermal front berada pada sisi sebelah timur selatan Selat Bali. Thermal front banyak terbentuk pada musim barat dan musim timur dengan musim barat sebagai puncak. Thermal front tidak berpengaruh terhadap jumlah hasil tangkapan ikan pelagis di perairan Selat Bali. Pada daerah penangkapan ikan tidak selalu terbentuk thermal front, diduga karena lokasi wilayah Selat Bali yang terlalu kecil sehingga thermal front lebih banyak terbentuk di daerah selatan perairan Selat Bali. Kata kunci:      arus, Selat Bali, SPL, thermal front


Author(s):  
Sartono Marpaung ◽  
Teguh Prayogo ◽  
Kuncoro Teguh Setiawan ◽  
Orbita Roswintiarti

Sea surface temperature (SST) data from S-NPP VIIRS satellite has different spatial resolution with SST data from Himawari-8 satellite. In this study comparative analysis of potential fishing zones information from both satellites has been conducted. The analysis was conducted on three project areas (PA 7, PA 13, PA 19) as a representation Indonesian territorial waters. The data used were daily  for both satellites with a period  time from August 2016 to December 2016. The method used was Single Image Detection (SIED) to detect thermal fronts. Method of mass center point for determining potential fishing zones coordinate point from result thermal front detection. Furthermore, an analysis of overlapping was done to compare the coordinate point information from both satellites. Based on data analysis that had been done, the result showed that potential fishing zones coordinate points of Himawari-8 satellite was mostly far from potential fishing zones coordinate point of S-NPP VIIRS. The coordinate points whose positionswere close together or nearly same from both satellites was only about 20 %. Differences in potential fishing zones coordinate positions occur due to the effect of different spatial resolutions of both satellite data and the size of the front thermal events that had high variability. The ideal potential fishing zones coordinate points information was probably a combination of the potential fishing zones coordinate points of S-NPP VIIRS and Himawari-8 by making two adjacent coordinate points to be a single coordinate point. Field validation testing was required to prove the accuracy of the coordinate point.


2012 ◽  
Vol 121 ◽  
pp. 118-124 ◽  
Author(s):  
Wesley J. Moses ◽  
Anatoly A. Gitelson ◽  
Sergey Berdnikov ◽  
Vladislav Saprygin ◽  
Vasily Povazhnyi

Author(s):  
Hasan Sitorus ◽  
Zulham Apandy Harahap ◽  
Tifani Zianida

The east coast of North Sumatra is part of the Malacca Strait, a highly utilized fishing area. One of the commodities that can be harvested is the Yellowstripe Scad (Selaroides leptolepis). Through oceanography parameters, specifically temperature and chlorophyll-aconcentrations, it is possible to determine optimal fishing grounds which can be used as guidelines. One of the satellites that can detect sea surface temperature (SST) and chlorophyll-a concentrations is Aqua (EOS PM),which is equipped with a Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Data on the Yellowstripe Scad (Selaroide sleptolepis) were obtained from the Belawan Ocean Fishing Port (OFP). Based on the analysis of MODIS images from the Aqua satellite, the sea surface temperature of theeast coastal waters of North Sumatra in 2012 - 2016 ranged from 29oC – 32oC with chlorophyll-a concentrations ranging from 0.19 - 5.26 mg/m³. The largest harvest occurred during the west monsoon with a value of 143.46 tons and the lowest was during the east monsoon with a value of 139.87 tons. Yellowstripe Scad harvest has a negative correlation with the sea surface temperature with a correlation value of -0.365. Chlorophyll-a concentrations and harvest amount have a positive correlation value of 0.660. Yellowstripe Scad is predicted to yield the largest harvest during the west monsoon (December-February) between the Asahan and Labuhanbatu Regencies at coordinates 2.68oN - 2.74oN and 100.37oE - 100.44oE.


Author(s):  
. Safruddin ◽  
Rachmat Hidayat ◽  
Mukti Zainuddin

This study aimed to map the oceanographic conditions and, based on that, to determine the favorable condition of skipjack tuna fishing ground in Fisheries Management Area (FMA) 713. This condition includes sea surface temperature (SST) and chlorophyll-a concentration. The primary data, such as fishing ground position and fish catch per trip, was collected by following the fishing operations that utilized pole and line (in Bone Gulf and Flores Sea) and purse seine fishing operations (in Makassar Strait). The secondary data, such as SST and chlorophyll-a, was derived from oceanographic satellite image data. The result showed that from January to August 2019, the skipjack tuna tends to occupy off shore areas where the sea surface temperature is between 29 - 29.5 oC and the chlorophyll-a density is between 0.10 to 0.15 mg.m3.


2020 ◽  
Vol 200 ◽  
pp. 06002
Author(s):  
Dandi Arianto Pelly ◽  
Muh Aris Marfai ◽  
Evita Hanie Pangaribowo ◽  
Akhmad Fadholi

This study aimed to identify the effect of the positive Indian Ocean Dipole (IOD) phenomenon on the spatial, temporal distribution of chlorophyll-a concentrations in the East Season in Padang Sea in 2019. The method used in this research was the Kriging analysis method applied in oceanographic parameter satellite imagery extraction point data. By applying the method, we produced the maps of the spatial distribution variation of chlorophyll-a content and Sea Surface Temperature (SST). The data of IOD events in 2019 showed the occurrence of a strong positive IOD phenomenon that caused anomaly in the Sea Surface Temperature (SST) in Padang Sea. The interpretation of Aqua-Modis level 2 satellite image data showed that the sea surface temperature during the East Season was relatively cold, which was in the minimum temperature ranging from 18.5-22°C with a normal temperature condition of 28-29°C. The minimum chlorophyll-a concentration in the East Season was 0.252 mg/m3; while the maximum value reached 18.5 mg/m3. The distribution value of chlorophyll-a concentration was 1.028 mg/m3.The RMSe Cross Validation value obtained was 0.504 for SST and 0.363 for chlorophyll-a with a mean SST of -0.0005 and mean chlorophyll-a of -0.0039.


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