• Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.256-264
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• 2024

Small pelagic fish populations have long been exploited by various fishing gears in the Natuna Sea, and since the 1970s, purse seine exploitation has expanded to offshore fishing grounds. Various small pelagic fish species are exploited from these waters including spotted sardinella (Amblygaster sirm). This research was conducted for 22 months, from March 2019 to December 2020. The fish sample was taken from the purse seine fleet's catch in the fisheries management area (FMA) 711 Natuna Sea and Karimata Strait, which was brought to Pemangkat fishing port in the West Kalimantan Province, Indonesia. This paper aims to determine the exploitation status of spotted sardinella in the Natuna Sea as a recommendation material for management policies. The methods used in this analysis are estimated age, cohort, population parameters, and spawning potential ratio of spotted sardinella. The results show three primary cohorts of spotted sardinella in the Natuna Sea, with ages ranging from 9 months to 3.1 years and a maximum attainable age (longevity) of 4.3 years. The asymptotic value (L_∞) is 21.79 cmFL in length, with a growth rate (K) of 0.65 per year. The natural mortality rate (M) was 1.19, the total mortality rate (Z) was 2.19, and the fishing mortality rate (F) was 0.99. The exploitation rate (E) was 0.45 and the stock status was still in a sustainable condition. Therefore, the sardinella fisheries can be developed using a precautionary approach and focus on the ecosystem sustainability of FMA 711.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1526-1531
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• 2024

¹³¹I is a fission product produced in a nuclear reactor by irradiating tellurium dioxide, with a half-life of 8.02 day. The most important and widely used method for making ¹³¹I is irradiation using a nuclear reactor and post-irradiation followed by dry distillation. The advantage of the dry distillation process is that the process and the equipment are relatively simple, namely TeO₂ (m.p. 750 ℃), which can withstand heating during reactor irradiation. Based on TeO₂ irradiation by neutron following the technique of dry distillation was explained for production of ¹³¹I on a large scale. A dry distillation followed the radioisotope production operation using the 30 MW GA Siwabessy nuclear reactor to meet national demand. TeO₂ targets are 25 and 50 g irradiated for 87-100 h. The resulting ¹³¹I activity is 20.29339-368.50335GBq. According to the requirements imposed on the radionuclide purity of the preparation, the contribution of ¹³¹I training in the resulting preparation was not less than 99.9 %

• Fisheries and Aquatic Sciences
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• v.26 no.12
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• pp.738-751
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• 2023

The Sembilan Archipelago is famous for its great biodiversity, in which the humphead wrasse (Cheilinus undulatus) (locally named Napoleon fish) is the primary commodity (economically important), and currently, the environmental degradation occurs due to anthropogenic activities. This study aimed to examine the eco-environmental parameters and assess their influence on the abundance of humphead wrasse and other coral reef fish compositions in the Sembilan Archipelago. Direct field monitoring was performed using a visual census throughout an approximately one km transect. Coral cover data collection and assessment were also carried out. A coastal water quality index (CWQI) was used to assess the water quality status. Furthermore, statistical-based analyses [hierarchical clustering, Pearson's correlation, principal component analysis (PCA), and canonical correspondence analysis (CCA)] were performed to examine the correlation between eco-environmental parameters. The Napoleon fish was only found at stations 1 and 2, with a density of about 3.8 Ind/ha, aligning with the dominant composition of the family Serranidae (covering more than 15% of the total community) and coinciding with the higher coral mortality and lower reef fish abundance. The coral reef conditions were generally ideal for supporting marine life, with a living coral percentage of about > 50% in all stations. Based on CWQI, the study area is categorized as good and excellent water quality. Of the 60 parameter values examined, the phytoplankton abundance, Napoleon fish, and temperature are highly correlated, with a correlation coefficient value greater than 0.7, and statistically significant (F < 0.05). Although the adaptation of reef fish to water quality parameters varies greatly, the most influential parameters in shaping their composition in the study area are living corals, nitrites, ammonia, larval abundance, and temperature.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.3
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• pp.265-274
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• 2022

MSMEs in the food and beverage industry play a critical role in the Indonesian economy since they account for the majority of the manufacturing sector's GDP. Despite its importance, it is unable to compete on a worldwide scale due to a lack of technological adoption. As a result, the purpose of this study is to look into the concerns and challenges that F&B MSMEs have when it comes to technology adoption. An online survey of 626 MSMEs and in-depth interviews as well as focus groups with diverse stakeholders from four provinces, namely West Java, East Java, South Sulawesi, and North Sumatera, provided the data for this study. To be thorough, the approach used in the study is based on the Technology, Organization, and Environment (TOE) framework. According to the findings, the majority of MSMEs use technology for marketing and sales, mainly through e-commerce. Meanwhile, for a variety of reasons, most of them continue to rely on traditional and semi-automatic technologies for production. According to the TOE framework, MSMEs lack those three parts of the technology adoption framework, particularly the environmental aspect, which is mostly due to a lack of cooperation among stakeholders. Finally, as a policy proposal, we offer a comprehensive technology adoption strategy based on the findings through an integrated MSMEs development information system including many important stakeholders.

• Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.87-99
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• 2024

Global climate change, followed by an increase in anthropogenic activities in aquatic ecosystems, and species invasions, has resulted in a decline in aquatic organism biodiversity. The Batanghari River, Sumatra's longest river, is polluted by mercury-containing illegal gold mining waste (PETI), industrial pollution, and domestic waste. Several studies have provided evidence suggesting a decline in fish biodiversity within the Batanghari River. However, a comprehensive evaluation of the present status of biodiversity in this river is currently lacking. The species under investigation were identified through various molecular-based identification methods, as well as morphological identification, which involved the use of neighbor-joining (NJ) trees. All collected specimens were initially identified using morphological techniques and subsequently confirmed with molecular barcoding analysis. Morphological and DNA barcoding identification categorized all specimens (1,692) into 36 species, 30 genera and 16 families, representing five orders. A total of 36 DNA barcodes were generated from 30 genera using a 650-bp-long fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene. Based on the Kimura two-parameter model (K2P), The minimum and maximum genetic divergences based on K2P distance were 0.003 and 0.331, respectively, and the average genetic divergence within genera, families, and orders was 0.05, 0.12, 0.16 respectively. In addition, the average interspecific distance was approximately 2.17 times higher than the mean intraspecific distance. Our results showed that the COI barcode enabled accurate fish species identification in the Batanghari River. Furthermore, the present work will establish a comprehensive DNA barcode library for freshwater fishes along Batanghari River and be significantly useful in future efforts to monitor, conserve, and manage fisheries in Indonesia.

• Fisheries and Aquatic Sciences
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• v.27 no.8
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• pp.515-524
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• 2024

The high economic value and demand for shark fin have significantly increased the vulnerability of the shortfin mako shark (Isurus oxyrinchus Rafinesque, 1810) population in the Indian Ocean, particularly in the southern region of Java and West Nusa Tenggara. This study utilized a length-based assessment method to evaluate the stock status of I. oxyrinchus. Over a span of eight years (2013-2021), data on length frequency and sex composition were collected. The length-based spawning potential ratio (SPR) was employed to investigate the stock status of the fishery. The findings revealed that I. oxyrinchus exhibited a large body size, with an asymptotic length estimated at 386.86 cm total length and a growth coefficient of 0.04/year . Females were more frequently captured than males, and evidence indicated a declining trend in the size of female sharks. A low SPR value of approximately 6% indicated the overfishing condition of mako shark. To ensure the sustainability of the shortfin mako shark population in the Indian Ocean, it is essential to develop effective management strategies through integrated cooperation among the government, fishers, traders, shark industries, and local communities.

• Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.213-224
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• 2024

Betta rubra, classified as endangered fish species by the International Union for Conservation of Nature (IUCN), has been successfully bred and raised in captivity for two generations under laboratory conditions. This study aimed to provide comprehensive information on the captive breeding of B. rubra, focusing on various parameters crucial for ex-situ conservation and domestication. The research involved breeding trials, embryo and larvae observation, first feeding experiments, larva and fry rearing trials, and the evaluation of growth and reproduction in two generations. The study revealed that the female B. rubra, with an average total length of 5.17 ± 0.15 cm and weight of 1.61 ± 0.06 g, produced an average of 73.67 ± 7.09 eggs, 34.33 ± 5.13 total larvae, and exhibited a hatching rate of 46.67 ± 5.77%. The embryogenesis process commenced on the day of spawning (dps) and continued until the eggs hatched at 6 dps. Larvae development and yolk absorption occurred from 0 to 6 days post-hatching (dph). The study also examined the impact of different initial feeding options, with chopped Tubifex resulting in the most significant in- crease (p < 0.05) in length. The growth pattern of B. rubra larvae showed slow initial growth during the first seven days, followed by a rapid exponential growth phase from day 8 to day 39. Two generations of B. rubra (G1 and G2) were successfully bred in captivity, with G2 showing a better tendency for growth in length and weight compared to G1. Notably, there were no significant differences (p > 0.05) in reproductive success between the wild-origin broodstock (G0), G1, or G2. This research contributes valuable insights into the captive breeding of B. rubra and its early life stages, offering critical information for the conservation and sustainable management of this endangered species. Further research is needed to explore the long-term effects of domestication on behavior, physiology, and phenotypic diversity.

• Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.145-158
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• 2024

Life history characteristics, habitat landscape, and historical events are believed to have shaped the patterns of genetic variation in many taxa. The bony lip barb, Osteohilus vittatus, represent a potamodromous fish that complete all life cycle in freshwater and is widely distributed in Southeast Asia. It usually lives in small rivers and other freshwater habitats, and movement between habitats for either food or reproduction has been typical. These life history characteristics may promote gene flow, leading to less structured populations. However, many freshwater habitats are fragmented, which restricts gene flow. We investigate how this interplay has shaped patterns of genetic variation and phylogeographic structure within this species in the Sundaland, a biodiversity hotspot with a complex geological history, using mitochondrial cytochrome oxidase I (mtCOI) as a genetic marker. Forty-six mtCOI sequences of 506 bp long were collected from ten localities, eight geographically isolated and two connected. The sequences were used for population genetic and phylogeographic analyses. Our results showed a low genetic diversity within populations but high between populations. There was a deep phylogeographic structure among geographically isolated populations but a lack of such structure in the connected habitats. Among geographically isolated populations, sequence divergence was revealed, ranging from 1.8% between Java and Sumatra populations to 12.2% between Malaysia and Vietnam. An indication of structuring was also observed among localities that are geographically closer but without connectivity. We conclude that despite high dispersal capacity, the joint effects of historical events, long-term geographic isolation associated with sea level oscillation during the Pleistocene, and restricted gene flow related to lack of habitat connectivity have shaped the phylogeographic structure within the O. vittatus over the Sundaland.

• Journal of the Korean Wood Science and Technology
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• v.52 no.1
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• pp.13-30
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• 2024

Swietenia mahagoni is one of the commercial timbers in Indonesia. Mahogany heartwood is an important characteristic as it relates to the natural durability and aesthetics of the wood. Lipophilic extractives are known to be involved in the heartwood formation process. Therefore, this study aims to determine the lipophilic compounds associated with heartwood formation. The n-hexane extract from sapwood and heartwood samples (1 to 5 years) was analyzed by gas chromatography-mass spectrometry. The results showed that the content of n-hexane extract ranged from 0.76% to 2.45% based on dry wood. The main group of compounds identified in the lipophilic fraction consisted of sterols (β-sitosterol, stigmasterol, campasterol, and cyclolaudenol), fatty acids (palmitic, oleic, linoleic, and stearic acid), and hydrocarbons (pentadecane, 1-octadecane, hexadecane, cyclotetracosane, cycloeicosane, and cyclooctacosane) after heartwood formation. In addition, the hydrocarbon fraction was the largest, followed by sterols, fatty acids, and 1-heneicosanol. In the radial variation, the distribution of fatty acids was greater in the sapwood than in the heartwood (4-year-old). However, the reverse pattern was found at the age of 5 years. The lipophilic fraction was generally more abundant in the heartwood compared to the sapwood, especially at 5 years of age, with much higher levels than when the heartwood was forming (4 years). These findings show that when the heartwood formation begins, the lipid composition was not fully metabolized at the beginning of heartwood formation compared to 5-year-old trees.

• Microbiology and Biotechnology Letters
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• v.52 no.2
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• pp.152-162
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• 2024

The microbial starter used to produce kefir beverages, kefir grain, contains a microbial exopolysaccharide called kefiran. Kefir grain consisting of water-insoluble polysaccharides, proteins, and fats, which can be applied as a multi-functional biopolymer. The mass of kefir grain can increase in the fermentation process of Kefir, but it is considered very slow. The purpose of this research is to study the impact of ammonium sulfate supplementation and yeast extract on reconstituted skim milk to increase the mass kefir grain and physical properties of kefiran. Results showed that the ammonium sulfate-supplemented substrate increased the mass of kefir grain by 547% in 14 days, with the condition that the substrate must be renewed every 2 days. Refreshing the substrate is considered one of the important factors. Supplementation on substrate did not appear to affect the viability of bacterial and yeast cells. Kefir grain produced from supplemented substrate also yields better thermal stability properties and has more functional groups than without supplementation. Two Lacticaseibacillus rhamnosus (RAL27 and RAL43) and one Limosilactobacillus fermentum (RAL29) were found to produce EPS. The three isolates also showed good skim milk fermentation ability after purification from kefir grain. The kefir grain produced in this study has the potential for wider application. This study also showed that kefir grain can be adjusted in quantity and quality through fermentation substrate engineering.