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All Journal Majalah Ilmiah Biologi BIOSFERA: A Scientific Journal
Arief Rachman
Research Center for Oceanography, Indonesian Institute of Sciences
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Environmental Science

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Study on The Potentially Harmful Benthic Dinoflagellates in Pari Island, Indonesia Hikmah Thoha; Arief Rachman; Mariana Destiana Bayu Intan; Gires Usup
Majalah Ilmiah Biologi BIOSFERA: A Scientific Journal Vol 37, No 1 (2020)
Publisher : Fakultas Biologi | Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.mib.2020.37.1.835

Abstract

Information on benthic dinoflagellates in Indonesia is rare since it often neglected in many microalgae researches. Thus, not much information is available about the ecology of benthic dinoflagellates in Indonesia, especially for three important genus, Gambierdiscus, Prorocentrum and Ostreopsis. Sampling were carried three times: in August, October, and December 2013. The sampling was conducted around Pari Island. Bethic Harmful Algal Blooms (B-HABs) were collected in each sampling site using a modified PVC rig with 15x10 cm screen (artificial substrate) which placed at the bottom of the water for 24 hours. Another form of a screen with leaf blade form, 30x5 cm was also deployed in each sampling site and left for 24 hours. In general, the different density of Prorocentrum, Gambierdiscus, and Ostreopsis were observed in various substrates in this research. Temporal variation of those three target genera was also found in this research, from the results so far, Prorocentrum was suggested as the most common benthic dinoflagellates in Pari Island. This genus was found in all substrates during two sampling periods in this study, except in sandy bottom substrate in October 2013. The highest density of Prorocentrum which observed in the screen placed in coral reefs area in October 2013, was 288 cells/100 cm2. The lowest of Prorocentrum density was observed in coral reefs area in October 2013, was 0.53 cells/g of wet weight.
Phytoplankton Community in The Lembeh Strait, Bitung and Wori Beach, Manado, North of Sulawesi, Indonesia Hikmah Thoha; Mariana D Bayu; Arief Rachman; Tan Senming
Majalah Ilmiah Biologi BIOSFERA: A Scientific Journal Vol 36, No 3 (2019)
Publisher : Fakultas Biologi | Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.mib.2019.36.3.834

Abstract

This study was conducted to understand phytoplankton community in the Lembeh Strait at Bitung and Wori Beach at Manado in October 2015. The phytoplankton samples were collected with vertical towing using Kitahara plankton net (mesh size 80 µm). Identification and enumeration were done using Sedgwick Rafter Counting Chamber (SRCC) under 100-400X magnification. Phytoplankton abundance in Wori, Manado were lower than Lembeh Strait. There were 24 genera of diatom group and nine genera of dinoflagellate group found in Wori and Lembeh Island waters. Total phytoplankton abundance in Wori ranged from 16,293.28 – 464,358.45 cells m-3 (station 6 and station 5, respectively). Whilst, In Lembeh Strait, Bitung, the highest abundance of phytoplankton was 2,300,407.33 cells m-3 and the lowest was 16,089.61 cells m-3. The composition of diatoms and dinoflagellates in Wori and Lembeh Strait was dominated by diatom which ranged from 80.70 % to 100.0%. Based on the mean contribution at each station among the two locations, there were 11 dominance genera of diatom and dinoflagellate groups which the mean contribution value above five percent. Those were including six genera of diatom group (Chaetoceros, Bacteriastrum, Nitzchia, Rhizosoleria, Thalassiothrix, and Thalassiosira) and five genera of dinoflagellate group (Ceratium, Prorocentrum, Protoperidinium, Pyrodinium, and Scriepsiella, Chaetoceros (diatom) and Protoperidinium (dinoflagellate) exhibit the highest genera representation in all diatom and dinoflagellate group among the two locations, with a 38 % and 36 % (respectively) mean contribution. Three genera which commonly known to cause harmful algal blooms (HABs) were observed in those two locations. Nitzschia from diatom group, Prorocentrum, and Pyrodinium from dinoflagellate group. Nitzschia was the most frequently found, almost recorded at all station in Wori, Manado and Lembeh strait, Bitung. The less frequent found of HABs causative organisms in those two locations was Pyrodinium.
Co-Authors Gires Usup Hikmah Thoha Mariana D Bayu Mariana Destiana Bayu Intan Tan Senming