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All Journal Jurnal Ilmu dan Teknologi Kelautan Tropis OLDI (Oseanologi dan Limnologi di Indonesia) Marine Research in Indonesia

Sam Wouthuyzen

Unknown Affiliation

Author-ID : 419902

Biochemistry, Genetics & Molecular Biology Decision Sciences, Operations Research & Management Earth & Planetary Sciences Environmental Science Library & Information Science

Published : 12 Documents Claim Missing Document

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Articles

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SHALLOW WATER HABITAT MAPPING AND REEF FISH STOCK ESTIMATION USING HIGH RESOLUTION SATELLITE DATA Vincentius P. Siregar; Sam Wouthuyzen; Andriani Sunuddin; Ari Anggoro; Ade Ayu Mustika
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 5 No. 2 (2013): Elektronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Shallow marine waters comprise diverse benthic types forming habitats for reef fish community, which important for the livelihood of coastal and small island inhabitants. Satellite imagery provide synoptic map of benthic habitat and further utilized to estimate reef fish stock. The objective of this research was to estimate reef fish stock in complex coral reef of Pulau Pari, by utilizing high resolution satellite imagery of the WorldView-2 in combination with field data such as visual census of reef fish. Field survey was conducted between May-August 2013 with 160 sampling points representing four sites (north, south, west, and east). The image was analy-zed and grouped into five classes of benthic habitats i.e., live coral (LC), dead coral (DC), sand (Sa), seagrass (Sg), and mix (Mx) (combination seagrass+coral and seagrass+sand). The overall accuracy of benthic habitat map was 78%. Field survey revealed that the highest live coral cover (58%) was found at the north site with fish density 3.69 and 1.50 ind/m2at 3 and 10 m depth, respectively. Meanwhile, the lowest live coral cover (18%) was found at the south site with fish density 2.79 and 2.18 ind/m2 at 3 and 10 m depth, respectively. Interpolation on fish density data in each habitat class resulted in standing stock reef fish estimation: LC (5,340,698 ind), DC (56,254,356 ind), Sa (13,370,154 ind), Sg (1,776,195 ind) and Mx (14,557,680 ind). Keywords: mapping, satellite imagery, benthic habitat, reef fish, stock estimation

MANGROVE COVERAGE CHANGE DETECTION USING LANDSAT IMAGERIES BASED ON HYBRID CLASSIFICATION IN KEMBUNG RIVER, BENGKALIS ISLAND, RIAU PROVINCE Romie Jhonnerie; Vincentius P Siregar; Bisman Nababan; Lilik Budi Prasetyo; Sam Wouthuyzen
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 6 No. 2 (2014): Electronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

ABSTRACT The limited scientific information and lack of attention from stakeholders on the status of mangroves in Kembung River functioned as a basis of this study. Four series of Landsat data recorded in 1996, 2002, 2010, and 2013 were used to map mangrove land cover and changes detection. Hybrid classification technique, a combination of the object-based and random forest classifications, were applied in this study. The result showed that based on hybrid classification, mangrove coverage was detected within 82.6-88.4% overall accuracy. Change detection analyses showed that the mangrove area of Kembung River was relatively stable. For nearly two decades, we found mangrove loss about 197.2 ha, gain of 251.1 ha, and unchanged of 2904.9 ha. Changes in mangrove were generally caused by anthropogenic factors such as mangrove replanting, logging, changes over the function of mangroves into the road, embankment, settlement, shrimp farms, and natural growth. Serious attention from various parties are needed to maintain the existence and sustainablility of mangrove ecosystems in Kembung River. Keywords: Mangrove, Sungai Kembung, monitoring, Landsat, hybrid classification

CHANGE DETECTION OF CORAL REEF HABITAT USING LANDSAT IMAGERY IN MOROTAI ISLAND NORTH MALUKU PROVINCE Nurhalis Wahiddin; Vincentius P Siregar; Bisman Nababan; Indra Jaya; Sam Wouthuyzen
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 6 No. 2 (2014): Electronik Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

ABSTRACT Scientific information on coral reef habitat changes of Morotai island is very limited to none. This study aimed to detect the change of coral reef habitats between 1996 and 2013, using Landsat imagery integrated with field data in 2012. The research was conducted in the coral reef ecosystem of Morotai Island in North Maluku province. Change detection analyses were conducted using supervised classifications and transformation depth invariant index (DII), with five habitat classes i.e., mixed-habitat, coral, seagrass, sand, and rubble. The result showed that in 1996-2002 there was a significant increase in the mix-habitat and rubble classes (11.3% and 32.5%), however, there was a siginifcant decrease in the sand, seagrass, and coral classes of -14.1%, -14.9%, and -16.6%, respectively. In 2002-2013, mixed-habitat, sand, and seagrass classes were increase by 1.1%, 13.3%, and 24.78%, respectively. Meanwhile, coral and rubble classes were decrease by -22.7% and -27.0%, respectively. Within the period of 1996-2013, there was about 43.6% loss of coral reef of Morotai island. This was probably caused by the increase of seas surface temperature nad and the increase of human activities in the region. Keywords: coral reef habitats, Landsat, change detection, Morotai Island

Early Warning System (EWS) for Algal Blooms using Satellite Imagery in Jakarta Bay Sidabutar, Tumpak; Sumarwati S Srimariana, Endang; Cappenberg, Hendrik; Wouthuyzen, Sam
Jurnal Ilmu dan Teknologi Kelautan Tropis Vol. 15 No. 3 (2023): Jurnal Ilmu dan Teknologi Kelautan Tropis
Publisher : Department of Marine Science and Technology, Faculty of Fisheries and Marine Science, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29244/jitkt.v15i3.52627

Teluk Jakarta telah mengalami eutrofikasi, terutama disebabkan oleh masuknya nutrien dari sumber pertanian, industri, dan perkotaan. Kelimpahan nutrien ini telah menyebabkan terjadinya marak alga yang signifikan. Studi dengan menggunakan data satelit Terra dan Aqua MODIS dari tahun 2004 hingga 2007 telah memantau marak alga ini dengan mengukur tingkat klorofil-a. Selama periode ini, terjadi kematian massal ikan yang secara langsung terkait dengan peristiwa marak alga, seperti yang dibuktikan dengan tingginya konsentrasi klorofil-a dan marak alge yang menutupi lebih dari seperempat teluk. Menariknya, tidak semua marak alge yang intens mengakibatkan kematian ikan massal. Studi tersebut menunjukkan bahwa kematian ini terutama disebabkan oleh kekurangan oksigen setelah periode marak alge mencapai puncak, yang diperburuk oleh sirkulasi air yang lemah di teluk ini. Penggunaan citra satelit untuk memantau marak alga adalah alat yang praktis untuk menerapkan sistem peringatan dini (EWS) di Teluk Jakarta. Citra satelit telah terbukti efektif dalam memantau marak alga ini dan dapat membantu mengembangkan sistem peringatan dini di Teluk Jakarta meskipun terdapat keterbatasan seperti adanya penutupan awan.

Co-Authors Ade Ayu Mustika Andriani Sunuddin Arafat, M. Y. Ari Anggoro Bisman Nababan Cappenberg, Hendrik Corry Corvianawatie, Corry Darmawan Darmawan Fasmi Ahmad Hanif, Andriyatno Indra Jaya Kusumo, Suryo LILIK BUDIPRASETYO Muhammad Abrar Permana, Syeprianto Romie Jhonnerie Salatalohi, Abu Sasanti Retno Suharti, Sasanti Retno Sugeha, Hagi Yulia Sugeha, Hagi Yulia Sumadhiharga, Kurnaen Sumadhiharga, Kurnaen Sumarwati S Srimariana, Endang Suwartana, Atjep Suwartana, Atjep Tumpak Sidabutar Vincentius P Siregar Wahidin, Nurhalis Yanuar, Yogi Yennafri, Yennafri

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