Journal of Fisheries Science and Technology

Investigating the potential of basalt fiber as a substitute for glass fiber in composite shipbuilding applications

Trần Doãn Hùng — 2025-12-29

In this paper, the essential properties of composite based on unsaturated Polyester matrix, Reversol P9509NW, reinforced by Basalt Fabric Type TBK-100 around 57% (wt%) from Basfiber®, Kamenny Vek Advanced Basalt Fiber company (Russia) which was donated by research cooperator – Faculty of Mechanical Engineering, Technical University of Liberec, Czech Republic. The tensile, flexural, abrasion and water absorption properties were in comparison with the properties of typical composite reinforced by one kind of glass fiber (55% by weight) which is used in shipbuilding, in accordance to QCVN 56:2013/BGTVT at once. The results show that the mechanical properties of composite reinforced by the basalt fiber are virtually identical or better than those of glass fiber, the water absorption properties are almost the same. Based on the preliminary results, we can temporarily conclude that basalt fibers are potential alternative to glass fibers in shipbuilding, moving towards sustainable development in Viet Nam.

DOI: https://doi.org/10.53818/jfst.04.2025.553

Building a sustainable e-commerce model for the distribution of Khanh Hoa’s signature seafood products

Lê Vũ Hoàng Giang — 2025-12-29

This paper introduces a research model that integrates e-commerce and green Logistics to enhance the efficiency of the seafood supply chain in Khanh Hoa province. Based on an in-depth analysis of production practices, distribution channels, and stakeholder requirements, the SeaFood platform is proposed as a comprehensive digital solution combining an online distribution network with a real-time transportation management system (TMS). The research methodology involves field surveys, SWOT analysis, and cost–benefit evaluation to validate the feasibility and effectiveness of the model. Findings indicate that the adoption of e-commerce, combined with green Logistics practices, not only reduces fuel costs and CO₂ emissions but also enhances transparency in order management, optimizes cold storage utilization, and fosters consumer trust. Furthermore, the study outlines a phased implementation roadmap tailored to the region's current Logistics infrastructure and technological capacity. The proposed model demonstrates strong potential for contributing to both sustainable development and digital transformation of Vietnam's seafood industry, providing practical insights for policymakers, enterprises, and researchers.

DOI: https://doi.org/10.53818/jfst.04.2025.588

Potential effects of pharmaceuticals in water bodies - especially those used in aquaculture

Nguyễn Văn Quỳnh Bôi — 2025-12-29

The release of pharmaceuticals into the aquatic environment has been becoming a global problem due to their potential impacts on aquatic ecosystems. The main sources are domestic wastewater, hospitals, industries and agriculture including aquaculture activities. In the aquatic environment, pharmaceuticals can undergo transformation processes such as photolysis, hydrolysis, biodegradation or accumulation in sediments. Although concentrations are usually low (ng/L to µg/L), in many cases they exceed ecological safety thresholds, affecting microorganisms, algae, fish and other aquatic species. Recorded impacts include hormone disruption, behavioral changes, reduced growth, reduced reproduction and emergence of antibiotic resistance. The aquaculture industry, especially in Vietnam, currently widely uses antibiotics, antiparasitics and chemicals for disease prevention and treatment, contributing significantly to water pollution by pharmaceutical residues. Therefore, strict management of the use of pharmaceuticals in aquaculture, raising public awareness and applying monitoring and control measures are urgent requirements to protect aquatic ecosystems.

DOI: https://doi.org/10.53818/jfst.04.2025.595

Assessment of the preservation status of seafood products on falling-net fishing boats in Lam Dong province

Võ Thị Thanh Vân — 2025-12-29

The article presents the results of an assessment of the status of product preservation on the falling-net boats in Lam Dong province by two methods: interviewing fishermen (30 samples) and directly surveying on the boats (30 samples) by pre-designed questionnaires and the FAO’s product classification method (1995). The results showed that the average length of the boat was (21.2 ± 3.6) m, and the average capacity of the main engine was (536.4 ± 213.8) CV. The main insulation material of the storage hold was foam (77.8%), with an average volume of (17.0 ± 7.8) m³, and a capacity of (5.8 ± 3.0) tons/hold; all boats used plastic trays and PE bags to contain products, someones you morecombined plastic barrels or tin trays. All vessels 100% employed the preservation method using crushed ice, among which 55.6% additionally applied freezing and 55,6% cold storage. The proportion of type A products ranged from 10.0 ÷ 100.0%, with an average of (46.9 ± 23.0)%; the value of type B was 1.8 times higher than that of type C, type C was 1.5 times higher than that of type D, and type D had a lower value than that of type A on average (34.5 ± 17.7)%.

DOI: https://doi.org/10.53818/jfst.04.2025.596

Effect of delivery methods on the protective efficacy of SiV vaccine in asian seabass Lates calcarifer (Bloch, 1790)

Nguyễn Thị Thanh Thùy — 2025-12-29

This study was conducted to evaluate the efficacy of different delivery methods of inactivated Streptococcus iniae vaccine (SiV) on the immune response and protective efficiency in Asian seabass (Lates calcarifer). The experiment consisted of three treatments: double immersion (NT1), immersion combined with injection (NT2), and double injection (NT3), and a control group injected with phosphate-buffered saline (PBS). Immunological parameters, including antibody titers, specific antibody IgM concentration, and Relative Percentage Survival (RPS), were assessed at 30, 90, and 180 days after the second immunization. The results showed that antibody titers, specific antibody concentration, and RPS decreased over time depending on the vaccine delivery methods. In particular, the double injection method (NT3) achieved the highest efficiency with antibody content reaching OD₄₉₂ = 0.405, agglutination titer of 1:147 and RPS protection efficiency reaching 94.4% at 30 days after immunization and maintained above 80% up to 180 days. The combined immersion injection method (NT2) also gave relatively high protection results (70.8% -76.7%). In contrast, immersion alone (NT1) only induced a low immune response and unsustainable protection. These findings confirm that intraperitoneal injection is the most effective strategy to induce strong and long-lasting immunity, making it suitable for large-scale commercial farming of L. calcarifer. Moreover, combined delivery methods as immersion followed by injection may offer a practical compromise between protective efficacy and operational feasibility in aquaculture.

DOI: https://doi.org/10.53818/jfst.04.2025.601

Isolation and selection of thermophilic microorganisms from hot springs with the ability to produce thermostable chitinase

Phạm Thị Lan — 2025-12-29

Hot mineral springs are the primary habitats of thermophilic microorganisms, and serve as sources of many important biologically active substances used in industry, especially heat-stable enzymes. This study aimed to isolate and screen thermophilic bacterial strains capable of producing thermostable chitinase from Truong Xuan hot spring in Ninh Hoa town, Khanh Hoa province. A total of 63 bacterial isolates were obtained from 20 samples of water, mud, and soil collected from the hot spring area, of which 18 demonstrated chitinase-producing activity. Among them, TX9 exhibited the highest chitinase activity, with a clear zone on a chitin agar plate of 25.33 ± 0,58 mm. TX9 produced the highest activity when incubated at 50^oC in a 180 rpm rotary shaker for 48 hours. This crude chitinase retained thermal stability within the temperature range of 50^oC to 70^oC for 60 minutes. Results of Gram staining and biochemical tests identified TX9 strain as Gram-positive, rod-shaped, catalase-positive, and spore-forming bacterium. Based on 16S rRNA gene sequence analysis, strain TX9 was identified as Bacillus licheniformis with 99.85% sequence similarity. These findings indicate that Bacillus licheniformis TX9 is a promising thermophilic bacterium for thermostable chitinase production, with potential industrial applications, especially in environmental treatment.

DOI: https://doi.org/10.53818/jfst.04.2025.602

Research on suitable parameters for drying belly split shrimp by infrared radiation combined with indirect solar energy

Trần Thị Bảo Tiên — 2025-12-29

This study aimed to identify the optimal drying conditions for enhancing the quality and processing efficiency of belly-split whiteleg shrimp (Litopenaeus vannamei) using a hybrid drying system that integrates infrared radiation and indirect solar energy (IR-SE). The experimental design was based on the Taguchi method, investigating four key technological parameters: drying chamber temperature (T), distance from the infrared source to the product surface (H), drying air velocity (V), and infrared lamp power (IP). Following data collection, Response Surface Methodology (RSM) was employed to simultaneously optimize multiple performance objectives, including reducing drying time, minimizing energy consumption, and maintaining desirable sensory attributes of the final product. The optimal drying parameters were determined as follows: a drying temperature of 60 °C, infrared power of 1800 W, air velocity of 1.88 m/s, and a source-to-product distance of 34.15 cm. During the drying process, the relative humidity of the drying air ranged from 20% to 25%. The initial moisture content of the belly-split shrimp was approximately 70%, which was reduced to 20 ± 1% after drying, corresponding to a total drying duration of 4.03 hours.

DOI: https://doi.org/10.53818/jfst.04.2025.603

CFD-based numerical simulation of the fao No. 5A fishing vessel towing test in calm water

Trần Đình Tứ — 2025-12-29

This study presents the application of Computational Fluid Dynamics (CFD) methods to establish a numerical towing tank for the resistance test of the FAO No. 5a ship model. The numerical solution to solve the Reynolds-Averaged Navier–Stokes (RANS) equations governing viscous free-surface flow around the hull is comercial code, Simerics MP and OrCA3D Marine CFD.

The study delivers two key outcomes. First, the proposed methodology for constructing a numerical towing tank using Orca3D and Simerics reduces the overall model preparation and setup time compared with general-purpose CFD solvers such as STAR-CCM++, ANSYS Fluent, or OpenFOAM. Second, in terms of hydrodynamic performance, the total resistance obtained at the ship’s service speed of 9 knots shows a relative deviation of only 4.89% compared with the experimental test data. In addition, high-resolution contour maps of pressure and velocity distributions were obtained, providing clear visualization of the flow field. Notably, the computed wave pattern along the hull and the free-surface elevation distribution exhibit strong agreement with the observed transverse and divergent wave systems generated by the ship in real operating conditions.

DOI: https://doi.org/10.53818/jfst.04.2025.604

Assessment of operational efficiency of offshore purse seine fishery in the Southeastern Vietnam

Nguyễn Phi Toàn — 2025-12-29

The study employed a randomized survey of vessel owners and captains operating purse seine fishing vessels in the offshore waters of the Southeastern region of Vietnam in 2024 to evaluate the operational performance of the fleet. Data were collected on vessel characteristics, onboard equipment, fishing grounds, target species, productivity, and economic efficiency from 90 purse seine vessels in Lam Dong, Ho Chi Minh City, and Dong Thap provinces. Results indicated that the offshore purse seine fleet primarily consisted of wooden-hulled vessels, with an average length ranging from 21.6 to 25.8 meters and main engine power between 447 and 928 HP. The vessels were generally well equipped with navigational and fishing devices, adequately meeting the requirements of offshore operations. The fleet operated year-round, averaging approximately 250 fishing days per year, with an annual catch of 219÷255 tons per vessel and an average profit of 1.18÷1.20 billion VND per vessel per year. The main target species were pelagic fish, with mackerel accounting for the largest proportion. A multiple regression analysis identified several factors significantly influencing profitability, including investment in fishing equipment, gear size, crew size, investment in navigational devices, engine power, and the number of fishing days. Among these, key factors requiring enhanced investment to improve operational efficiency included fishing equipment, engine power, and fishing effort (number of fishing days). Conversely, factors such as gear size, crew size, and investment in navigational devices should be reconsidered to optimize costs and increase profitability.

DOI: https://doi.org/10.53818/jfst.04.2025.608

Micro and nanoplastics in mariculture activity – the situation in Vietnam

Nguyễn Văn Quỳnh Bôi — 2025-12-29

Microplastics in general (≤ 1,000 μm) are increasingly released into marine and coastal environments from external sources (rivers, land, atmospheric deposition, etc.) and/or from marine activities (tourism, transportation, fishing, and aquaculture). This issue has become more serious and has attracted growing concern due to their harmful impacts on organisms, environment, and entire ecosystem — including components involved in mariculture. Numerous studies have shown that microplastics can accumulate in organisms and affect physiological, biochemical, and genetic processes, thereby influencing behavior, growth, and development. These effects ultimately reduce economic efficiency and pose potential risks to consumers, particularly for crustaceans, mollusks, and marine fish — the main species of Vietnam’s mariculture sector. Similar concerns exist in Vietnam, where data indicate that coastal areas are likely affected by plastic waste in general and microplastics in particular. Therefore, following the “precautionary approach,” it is necessary to investigate the problem and develop appropriate solutions to microplastic pollution in mariculture activity.

DOI: https://doi.org/10.53818/jfst.04.2025.612

Study on the physicochemical composition of farmed sandfish (Holothuria Scabra) from the coastal waters of Ninh Hoa, Khanh Hoa

Trần Văn Vương — 2025-12-29

The study evaluated several physicochemical composition on three size groups of sandfish (Holothuria scabra) 5-6 individuals/kg (small group), 3-4 individuals/kg (medium group) and 1-2 individuals/kg (large group), purchased from farming ponds in the Ninh Hoa sea area, Khanh Hoa. Results showed clear differences among the groups, specifically: Regarding the proportion of edible (meat), the small and medium groups had a lower than the large group by 8-10%; Regarding water content, the large group had the lowest water content (77.01%), nearly 6.5% lower than the small group and nearly 1.0% lower than the medium group. The medium group’s water content (78.91%) was almost 5.0% lower than the small group; For the indicators protein, lipid, carbohydrate, calcium, phosphorus, and total ash across the different sandfish groups, there were varying increases and decreases. Protein ranged from 61.60% to 74.34%, lipids from 3.16% to 5.89%, carbohydrates from 7.29% to 8.20%, calcium from 0.74% to 1.07%, phosphorus from 0.18% to 0.49%, while total ash decreased from 27.64% to 10.00%. Therefore, harvesting, processing, and using sandfish raw material from the larger-weight group will help improve meat recovery efficiency and increase the nutritional, mineral when using the same amount of raw material.

DOI: https://doi.org/10.53818/jfst.04.2025.618

Assessment of antibacterial activity of fresh garlic juice extract against Vibrio spp. isolated from hybrid grouper

Trần Vĩ Hích — 2025-12-29

The study was conducted to evaluate the antibacterial activity of fresh garlic extract from three garlic varieties (solo garlic, small clove garlic, and Chinese garlic) against two bacterial species, Vibrio harveyi and Vibrio alginolyticus. The agar diffusion assay showed that the garlic extract inhibited the growth of both Vibrio species, with inhibition zone diameters increasing proportionally with extract concentration. Solo garlic and small clove garlic produced significantly larger inhibition zones compared to Chinese garlic (P < 0.05). V. harveyi was more sensitive than V. alginolyticus at all tested concentrations.

The MIC and MBC assays revealed that the MIC values for V. harveyi ranged from 3.125–6.25%, with corresponding MBC values of 6.25–12.50%. For V. alginolyticus, both MIC and MBC values were higher, ranging from 6.25–12.50% and 12.50–25%, respectively. The MBC/MIC ratio ≤ 4 indicated that the fresh garlic extract exhibited bactericidal properties according to the criteria of Canillac and Mourey (2001).

Keyswords: garlic, V. harveyi, V. alginolyticus, MIC, MBC

DOI: https://doi.org/10.53818/jfst.04.2025.622