Analisis Distribusi Vertikal Plankton Menggunakan Penginderaan Jauh Akustik Bawah Air Dan Profil CTD

Ammar, Abdullah (2025) Analisis Distribusi Vertikal Plankton Menggunakan Penginderaan Jauh Akustik Bawah Air Dan Profil CTD. Masters thesis, Institut Teknologi Sepuluh Nopember.

Text 6016222005-Master_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (6MB) | Request a copy

Abstract

Underwater acoustic remote sensing merupakan metode yang efektif untuk mendeteksi dan memantau makhluk hidup di perairan, termasuk plankton, melalui analisis pantulan sinyal akustik (backscatter) menggunakan instrumen seperti single-beam echosounder. Metode ini memungkinkan pemetaan distribusi vertikal plankton di kolom air melalui respons akustik yang direpresentasikan oleh nilai Volume Backscattering Strength (Sv). Dalam penelitian ini digunakan Singlebeam Echosounder Simrad EK60 dengan frekuensi 38 kHz untuk memperoleh data intensitas pantulan dari kolom air, sedangkan parameter fisik perairan, yaitu suhu dan salinitas, diukur menggunakan CTD Seabird SBE 37-SMP. Analisis Signal-to-Noise Ratio (SNR) dilakukan untuk memastikan keandalan data akustik, yang menunjukkan pola penurunan eksponensial pada jarak dekat (0–20 m) dan cenderung linear setelah 30 m, dengan nilai tertinggi 87,92 dB pada 4 m dan menurun hingga 61,27 dB pada 79 m. Nilai SNR tetap berada di atas ambang keandalan (60 dB), meskipun mendekati batas bawah pada kedalaman >70 m. Hasil analisis Sv menunjukkan bahwa di CTD 2 nilai Sv berkisar antara -60 dB hingga -80 dB, sedangkan di CTD 1 berkisar antara -40 dB hingga -70 dB. Histogram distribusi Sv memperlihatkan puncak pada -65 dB (15%) di CTD 2 dan -70 dB (6,5%) di CTD 1. Kelimpahan plankton meningkat seiring bertambahnya kedalaman, dengan puncak kelimpahan di CTD 1 sebesar 743.725,31 ind/m³ pada kedalaman 39 m, sedangkan di CTD 2 mencapai 8.960.406 ind/m³ pada kedalaman 79 m. Penurunan suhu dan peningkatan salinitas berperan dalam pembentukan lapisan termoklin dan zona transisi densitas sebagai area akumulasi plankton. Nilai Sv yang tinggi berkorelasi positif dengan kelimpahan plankton, dan pola distribusi vertikal plankton mengindikasikan potensi keberadaan Deep Scattering Layer (DSL) pada lapisan yang lebih dalam.
====================================================================================================================================
Underwater acoustic remote sensing is an effective method for detecting and monitoring aquatic organisms, including plankton, through the analysis of acoustic backscatter signals using instruments such as single-beam echosounders. This method enables the mapping of vertical plankton distribution in the water column by analyzing acoustic responses represented by Volume Backscattering Strength (Sv) values. In this study, a Singlebeam Echosounder Simrad EK60 operating at a frequency of 38 kHz was used to collect acoustic backscatter intensity data, while physical parameters of seawater, including temperature and salinity, were measured using a CTD Seabird SBE 37-SMP. An analysis of the Signal-to-Noise Ratio (SNR) was performed to ensure the reliability of acoustic data, showing an exponential decrease in the near range (0–20 m) and a more linear pattern beyond 30 m. The highest SNR value was recorded at 87.92 dB at 4 m and gradually decreased to 61.27 dB at 79 m, remaining above the minimum reliable threshold (60 dB) but approaching the lower limit at depths greater than 70 m. The Sv analysis revealed that in CTD 2, Sv values ranged from -60 dB to -80 dB, while in CTD 1, they ranged from -40 dB to -70 dB. The Sv histogram showed peak distributions at -65 dB (15%) in CTD 2 and -70 dB (6.5%) in CTD 1. Plankton abundance increased with depth, with the highest abundance recorded at 743,725.31 ind/m³ at 39 m in CTD 1, and 8,960,406 ind/m³ at 79 m in CTD 2. Decreasing temperature and increasing salinity contributed to the formation of a thermocline and density transition zones, which served as accumulation areas for plankton. High Sv values correlated positively with high plankton abundance, and the vertical distribution patterns indicated the potential presence of a Deep Scattering Layer (DSL) at deeper layers.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Underwater Acoustic Remote Sensing, Volume Backscattering Strength (Sv), kelimpahan plankton, termoklin, Singlebeam Echosounder, Simrad EK60. underwater acoustic remote sensing; Volume Backscattering Strength (Sv), plankton abundance, thermocline, Singlebeam Echosounder, Simrad EK60
Subjects:	G Geography. Anthropology. Recreation > G Geography (General) > G70.5.I4 Remote sensing G Geography. Anthropology. Recreation > GC Oceanography > GC101.2 Seawater--Analysis G Geography. Anthropology. Recreation > GC Oceanography > GC1018.5 Ocean zoning.
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Geomatics Engineering > 29101-(S2) Master Thesis
Depositing User:	Abdullah Ammar
Date Deposited:	29 Jul 2025 07:31
Last Modified:	29 Jul 2025 07:31
URI:	http://repository.its.ac.id/id/eprint/122812

Actions (login required)

View Item