Composition, Density and Spatial Distribution of Zooplankton in Inner Ambon Bay, Indonesia

J Latumeten,F S Pello,V D V Latumeten

doi:10.34257/gjsfrcvol21is5pg7

Abstract

Inner Ambon Bay is part of Ambon Bay; it is semi-closed area and a small pelagic fish fishing ground, especially anchovy. The anchovy is a zooplankton predator; therefore the existence of anchovy is affected by the abundance of zooplankton. The aims of the research are to obtain information on the composition, density, and spatial distribution of the zooplankton in these waters. Data of zooplankton composition were obtained from sampling by using plankton net at ten observation stations. Meanwhile, data of densities were collected using a scientific hydroacoustic system, BioSonic DTX supported with split-beam technology, on six parallel transect lines and one cross-parallel transect line. Geostatistical analyses technique was used to describe horizontal distributions of zooplankton, and vertical distributions pattern were plot in the graphs. The result shows that the zooplankton community is dominated by Copepod and meroplankton. The highest average density was found in August (9393 ind./m2),while the lowest density was in June (903 ind./m2).

Highlights

Inagaki, 1992; Castillo et al, 1996; Fischer and Visbeck, Ambon Bay is located in Maluku Province, Indonesia
Zooplankton density analysis was conducted at each one-meter water thickness from transducer surface to bottom according to BioSonic (2004) with the following formula: The variogramis obtained according to MacLennan and Simmonds (2005) with the following formula: Where ZPUA is the zooplankton density per m2 which is the sum of absolute vertical density, AD, h = distance between the sample locations and zooplankton per cubic meter (ZPCM)
The krigging (Deutsch and Journel, 1992) with the following copepod was dominated by Oithona, Acrocalanus, formula: Eucalanus Macrosetella

Summary

Introduction

1992; Castillo et al, 1996; Fischer and Visbeck, Ambon Bay is located in Maluku Province, Indonesia. Based on depth detection using a hydroacoustic device in 2010, it was known that the maximum depth of this area amount to 45m (Latumeten and Pello, 2019) This area is small pelagic fishing ground, in particular the anchovy. Zooplankton density from vertical hydroacoustic sampling within each ESDU was estimated following BioSonic (2004) as follows: Where ZPCM is a zooplankton density per m3,Sv is the volume of back-scattering strength, and σBS is the mean back-scattering cross-section (cross-section of zooplankton size assessed acoustically) from detected zooplankton. Zooplankton density analysis was conducted at each one-meter water thickness from transducer surface to bottom according to BioSonic (2004) with the following formula: The variogramis obtained according to MacLennan and Simmonds (2005) with the following formula: Where ZPUA is the zooplankton density per m2 (unit area) which is the sum of absolute vertical density, AD, h = distance between the sample locations and zooplankton per cubic meter (ZPCM).

Result and Discussion

Conclucion

BioSonicInc 2003 The BioSonics DT-XTM

Findings

Deutsch C V and Journel A G 1992 GSLIB