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RICHARDUS KASWADJI
Ilmu Kelautan, Fakultas Perikanan dan Ilmu Kelautan Institut Pertanian Bogor
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences

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DISTRIBUTION OF MONOGONONT ROTIFERS, Branchionus spp IN NORTH SULAWESI Rimper, Joice; Kaswadji, Richardus; Widigdo, Bambang; Sugiri, Nawangsari; Rumengan, Inneke
Marine Research in Indonesia Vol 32, No 2 (2007)
Publisher : Research Center for Oceanography - Indonesian Institute of Sciences (LIPI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (7372.399 KB) | DOI: 10.14203/mri.v32i2.443

Abstract

In order to characterize the distribution pattern of rotifers Brachionus spp. in North Sulawesi, sample collections have been conducted at four locations, two at east coast and other two at west coast of North Sulawesi peninsula, which are connected to Maluku and Sulawesi Seas, respectively. At each location, a 40 p.m mesh size plankton net with a 0.3 m opening diameter was horizontally towed at three sites to represent coastal water, estuary and brachkiswater pond. Sampling periods were in January and August 2005 to represent west monsoon and east monsoon, respectively. Each sampling was performed twice a day during high and low tide. Some environmental factors were also measured in situ during the sampling. Three species of Brachionus were found during the survey, Brachionus rotundiformis, B. caudatus and B. quadridentatus. Their abundances were significantly different, both between locations and sampling sites. However, among the similar habitat such as between Manembo-nembo and Minanga brachkishwater ponds, B. rotundiforms abundance was not significantly different. This species was the most abundant compared to the other two species, in average 1984,4 ind/m3, while the other species was as low as 26,1 ind/m3 and 212,9 ind/m3 for B. caudatus and B. quadridentatus, respectively. The abundance of rotifers in northern areas connected to Molluccas Sea is higher compared to those in the southern areas connected to Sulawesi Sea. Distribution of B. caudatus is very similar to those of B. rotundiformis, while B. quadridentatus appears to have its specific pattern. Results of this study suggest that the abundance and species composition of the rotifers reflect trophic status of the aquatic ecosystem in the area. It is still awaiting future studies to elaborate the impacts of the trophic gradients in horizontal distribution of rotifers. Therefore, it is necessary to conduct a long term monitoring with emphasis on the structure of rotifer assemblages in a variety of sites subjected to environmental perturbations, including anthropogenic contaminant inputs.
DISTRIBUTION OF MONOGONONT ROTIFERS, Branchionus spp IN NORTH SULAWESI Rimper, Joice; Kaswadji, Richardus; Widigdo, Bambang; Sugiri, Nawangsari; Rumengan, Inneke
Marine Research in Indonesia Vol 32 No 2 (2007)
Publisher : Research Center for Oceanography - Indonesian Institute of Sciences (LIPI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (7372.399 KB) | DOI: 10.14203/mri.v32i2.443

Abstract

In order to characterize the distribution pattern of rotifers Brachionus spp. in North Sulawesi, sample collections have been conducted at four locations, two at east coast and other two at west coast of North Sulawesi peninsula, which are connected to Maluku and Sulawesi Seas, respectively. At each location, a 40 p.m mesh size plankton net with a 0.3 m opening diameter was horizontally towed at three sites to represent coastal water, estuary and brachkiswater pond. Sampling periods were in January and August 2005 to represent west monsoon and east monsoon, respectively. Each sampling was performed twice a day during high and low tide. Some environmental factors were also measured in situ during the sampling. Three species of Brachionus were found during the survey, Brachionus rotundiformis, B. caudatus and B. quadridentatus. Their abundances were significantly different, both between locations and sampling sites. However, among the similar habitat such as between Manembo-nembo and Minanga brachkishwater ponds, B. rotundiforms abundance was not significantly different. This species was the most abundant compared to the other two species, in average 1984,4 ind/m3, while the other species was as low as 26,1 ind/m3 and 212,9 ind/m3 for B. caudatus and B. quadridentatus, respectively. The abundance of rotifers in northern areas connected to Molluccas Sea is higher compared to those in the southern areas connected to Sulawesi Sea. Distribution of B. caudatus is very similar to those of B. rotundiformis, while B. quadridentatus appears to have its specific pattern. Results of this study suggest that the abundance and species composition of the rotifers reflect trophic status of the aquatic ecosystem in the area. It is still awaiting future studies to elaborate the impacts of the trophic gradients in horizontal distribution of rotifers. Therefore, it is necessary to conduct a long term monitoring with emphasis on the structure of rotifer assemblages in a variety of sites subjected to environmental perturbations, including anthropogenic contaminant inputs.
Penyusunan Model untuk Penangkapan Berkelanjutan Ikan Pelagis dengan Pendekatan Jenjang Trofik di Selat Makassar Kaswadji, Richardus; Hatta, Muhammad; Umar, Nur Asia
Jurnal Natur Indonesia Vol 12, No 1 (2009)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (474.496 KB) | DOI: 10.31258/jnat.12.1.67-74

Abstract

Observations on pelagic fish catch activities using bagan Rambo in Makassar Strait had been conducted in 2005and 2006 to obtain physical, chemical, and biological data and their processes in the operation of bagan Rambo inthe observation sites. The objective of the study was to overcome the overfishing problems which have beenhappenning in Makassar Strait, using a model of the trophic level approaches. Nine observation stations were setin three transects perpendicular to the coast. The measurement of physical, chemical, and biological parameterswere conducted monthly. Biological parameters measured were chlorophyll-a, and the abundance of phytoplanktonand zooplankton. Phytoplankton primary productivity, grazing mortality of phytoplankton by zooplankton, numberof catch of fish, and fish feeding habit were also measured. Run of the built model based on the data obtainedshowed that with the present catch-pressure (assuming that this was the start of catching operation), there wouldbe an overfishing starting in the 26 th or 27th month onward. Meanwhile, if the catch were half of the present, thenthere would be an overfishing in the 31 st or 32nd month, but would back to the sustainable production months afterthat. The model is still being developed by finding and adding more accurate data and parameters.
Co-Authors Inneke F. M Rumengan Joice R.T.S.L Rimper Muh. Hatta Nawangsari Sugiri Nur Asia Umar