Jurnal Ilmiah Perikanan dan Kelautan

Back Meter Vol 17 No 3

Rozi — Sat, 27 Sep 2025 00:00:00 +0700

Evaluation of Fatty Acid Profile in Red Tilapia Fed Black Soldier Fly Larvae and Tofu Waste-Based Diets

Thu, 24 Jul 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

Feed formulations based on black soldier fly (BSF) larvae and tofu waste meet the quality requirements based on the Indonesian National Standard
Feed formulations based on black soldier fly (BSF) larvae and tofu waste improve fish growth performance comparable to commercial feed
Feed formulations based on black soldier fly (BSF) larvae and tofu waste did not increase the level of cholesterol content in fish flesh
Fish flesh with black soldier fly (BSF) larvae and tofu waste diet have higher total fatty acid content compared to commercial feed

Abstract

Despite growing interest in sustainable aquaculture, studies on the combined use of Black Soldier Fly Larvae (BSFL) and tofu waste as alternative protein sources in tilapia diets, particularly their effects on fatty acid profiles, remain limited. This study evaluates the effects of fish feed formulated with BSFL and tofu waste on the growth performance, proximate composition, and fatty acid profile of red tilapia (Oreochromis niloticus). Experimental diets included: commercial feed, dried BSFL, and a combination of BSFL:tofu waste. Fish were reared for eight weeks under controlled conditions. Treatment with BSFL:tofu waste exhibited superior growth performance, with the highest weight gain (102.88%) and length gain (33.75%). Proximate analysis revealed significant variations across treatments, with a combination of BSFL:tofu waste achieving the highest caloric value (110.71 cal/g) and fat content (3.75%) while maintaining protein levels comparable to commercial feed. Fatty acid analysis showed a combination of BSFL:tofu waste enhanced total fatty acid content (77.92%), predominantly polyunsaturated fatty acids (PUFAs), increasing from 37.34% in commercial feed to 47.04%. Essential fatty acids, including DHA and linoleic acid, were elevated in a combination of BSFL:tofu waste, indicating improved nutritional quality. Cholesterol levels remained unaffected among treatments. These findings suggest that combining BSFL and tofu waste can enhance fish feed quality, optimize growth performance, and improve the nutritional value of red tilapia. Future research should explore refining feed formulations to maximize nutrient stability and sustainability for broader aquaculture applications.

Steroid Hormone Profile and Sperm Quality of Silver Pompano (Trachinotus blochii) Fed Tribullus terrestris Extract and Gonadotropin Hormone

Thu, 24 Jul 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

1. Hormonal approaches are needed for the maturation of the broodstock's gonads;

2. The use of gonad maturation stimulants, both hormonal and herbal, in the aquaculture sector has been widely used, where hormonal and phyto-biotic induction can enhance gonad maturation in fish.

3. The use of phyto-biotic, such as Tribulus terrestris, has been tested to enhance reproduction in fish.

4. Feeding Tribulus terrestris extract enhances the reproductive performance of male silver pompano broodstock by improving weight growth, testosterone levels, gonad maturation, and sperm volume.

Abstract

Male broodstock of silver pompano often exhibit delayed gonadal development, which prolongs the broodstock maintenance period and increases production costs. To address this issue, dietary supplementation with bioactive compounds and hormonal inducers has been explored to stimulate reproductive maturation. Among these, plant-derived extracts such as Tribulus terrestris and exogenous hormones like human Chorionic Gonadotropin (hCG) are of interest due to their potential to enhance steroidogenesis and accelerate gonadal development. This study examined the impact of T. terrestris extract (ETT) and hCG on the steroid hormone profile, sperm quality, and gonadal histology of male silver pompano. Five treatment groups were established with varying ETT (mg/kg of diet) and hCG (IU/kg of body): T1 (0 + 0), T2 (50 + 0), T3 (250 + 0), T4 (50 + 1000), and T5 (250 + 500), each replicated eight times. Results revealed that ETT at 250 mg/kg (T3) significantly improved reproductive parameters, including absolute weight gain, gonadal development, and semen volume. Histological analyses further indicated advanced stages of gonadal maturation in treated groups, accompanied by increased plasma testosterone levels, which stimulated spermatogenesis and sperm cell formation. Optimal sperm quality—characterized by enhanced motility and seminal volume—was observed at the T3 dosage, although sperm density showed limited variation. These findings underscore the potential of T. terrestris extract as a practical dietary strategy to enhance reproductive efficiency in silver pompano aquaculture, contributing to improved productivity and sustainability. Further studies are recommended to refine dosages and ensure consistent outcomes across production systems.

Front Meter Vol 17 No 3

Rozi — Sat, 27 Sep 2025 00:00:00 +0700

Bioactive Peptides from Indonesian High-Protein Fermented Foods: A Promising Source of Functional Compounds

Wed, 27 Aug 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

Fermentation improves the biological function of proteins.
Bioactive peptides increase after fermentation.
Indonesia has many unexplored sources of bioactive peptides in fermented food.
Indonesian high-protein fermented foods have high bioactivity potential.
Research is needed on the bioactivity of Indonesian bioactive peptides sources for broader health implications.

Abstract

Bioactive peptides (BPs) are short protein fragments with significant physiological functions, including antioxidant, antihypertensive, antimicrobial, and antidiabetic activities. These compounds are commonly released during fermentation, making high-protein fermented foods (HPFF) a promising source of natural health-promoting agents. Indonesia, with its rich biodiversity and long-standing tradition of fermentation, offers a unique variety of traditional HPFF. However, the potential of these indigenous products as BP sources remains underexplored and poorly represented in the global literature. This review aims to examine Indonesian traditional HPFF as a source of BPs, categorize them based on raw material, and highlight their functional and health-related properties. A literature review was conducted using publications from Scopus, PubMed, ProQuest, Google Scholar, and SINTA (2000–2023). The search applied Boolean strategies and the PEO (Population, Exposure, Outcome) framework to identify relevant studies on fermented foods, bioactive peptides, and their biological activities. Indonesian HPFF including tempeh, rusip, dangke, pekasam, and cangkuk contain BPs with diverse bioactivities. Tempeh shows antidiabetic and antihypertensive potential; rusip exhibits antioxidant and cholesterol-lowering effects; dangke and cangkuk demonstrate antimicrobial and ACE-inhibitory activities. These functional properties are influenced by substrate type (e.g., legumes, fish, milk), microbial composition (lactic acid bacteria, Bacillus spp., yeasts), and fermentation conditions. Notably, certain Indonesian HPFF exhibit multi-functional peptides with synergistic health effects, suggesting significant therapeutic promise. This review bridges a critical knowledge gap by consolidating evidence on BPs from Indonesian HPFF. It provides a foundation for future investigations into peptide bioactivity, supports functional food innovation, and highlights the global relevance of Indonesia’s fermentation heritage in health science and sustainable nutrition.

Assessing various administration strategies for dsRNA vaccine delivery: a concise review of VP15-WSSV research progress in tiger shrimp Penaeus monodon

Thu, 17 Jul 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

1. The dsRNA application should correspond to the developmental stages of shrimp
2. Immersion method was commonly used for larvae for handling many individuals
3. Injection technique effectively delivered dsRNA to cells but was unsuitable for large-scale
4. Oral administration of pellet-enriched dsRNA was applicable to apply on shrimp larvae, juveniles, and broodstocks

Abstract

RNAi technology offers a novel powerful approach to silence gene expression by introducing double-stranded RNA (dsRNA) into the cell to degrade the mRNA at the post-transcriptional stage. An administration method of dsRNA delivery is one of the main considerations in applying the dsRNA vaccine for controlling pathogen infections. This mini-review was focused on the evaluation of three different methods (immersion, injection, and oral administration) of VP15-dsRNA vaccine delivery to the tiger shrimp post-WSSV challenge test. The immersion method was generally applied for the larval stage of tiger shrimp and seemed to be a simple technique for a large number of individuals in a small tank. The VP15-dsRNA application by immersion improved the survival of tiger shrimp larvae by 3.9% compared to the control groups. The injection technique was an effective way to deliver dsRNA to the cell, but it is difficult to apply in a large number of individuals or populations. The injection of VP15-dsRNA increased significantly the survival rate, proPO, and THC of tiger shrimp. A higher survival rate (75%) was exhibited in tiger shrimp injected with in vivo and in vitro VP15-dsRNA than in the control. Oral administration by pellet-enriched VP15-dsRNA was a useful way for larvae, juveniles, and broodstocks, but it has limitations since the pellet leaches into the water. The application of the VP15-dsRNA vaccine on the feed significantly enhanced the 26.7% higher survival rate compared to the control. The higher survival was also supported by a higher number of THC. The three VP15-dsRNA delivery methods provide potential approaches to increase tiger shrimp resistance to control pathogen infection

Response Surface Methodology for Optimized Concentration of Gum Arabic, Maltodextrin, and Whey Protein Isolate in Arthrospira platensis Phycocyanin Microcapsules

Puspa Pebriyanti, Siti Ari Budhiyanti, Nurfitri Ekantari — Mon, 28 Jul 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

Phycocyanin could be encapsulated by the spray-drying process with gum Arabic (GA), maltodextrin (MD), and whey protein isolate (WPI) as coating materials.
The selected optimal formula for phycocyanin microcapsules consisted of 8.3% GA, 11.7% MD, and 5.2% WPI.
The optimum formulation can produce phycocyanin microcapsules meeting 76.56% of the desired targets.
The concentrations of three encapsulant ingredients (GA, MD, and WPI) influenced the resulting characteristics, e.g., phycocyanin content, antioxidant activity, encapsulation efficiency, phycocyanin retention, solubility, and particle size

Abstract

Phycocyanin is a blue-colored phycobiliprotein in Arthrospira platensis known for its antioxidant properties. Due to its sensitivity to pH, temperature, light, oxygen, and moisture, protecting phycocyanin pigments often involves microencapsulation through spray drying. This process allows the pigments to be rapidly entrapped within a wall material. The wall material for these microcapsules was composed of gum arabic, maltodextrin, and whey protein isolate. This study aimed to determine the optimal concentrations of these components to optimize encapsulation performance. Optimization was performed using the Minitab application with Response Surface Methodology (RSM) and a Central Composite Design (CCD). The independent variables were the concentrations of gum arabic, maltodextrin, and whey protein isolate, while the response variables measured included yield, phycocyanin content, antioxidant activity, encapsulation efficiency, phycocyanin retention, solubility, and particle size. Scanning electron microscopy (SEM) was used to analyze the morphology of the optimized microcapsules. The Minitab analysis recommended 20 potential optimization solutions, with the highest desirability value of 0.7656. The selected optimal formula consisted of 8.3% gum arabic, 11.7% maltodextrin, and 5.2% whey protein isolate. Predicted response values for this formulation were as follows: yield 75.30%, phycocyanin content 4.55%, antioxidant activity 48.87%, encapsulation efficiency 98.98%, phycocyanin retention 68.57%, solubility 95.15%, and particle size 212.73 nm. Validation results confirmed a yield of 81.70%, phycocyanin content of 3.56%, antioxidant activity of 52.08%, encapsulation efficiency of 93.96%, phycocyanin retention of 62.42%, and a particle size of 212.73 nm. These findings indicate that the proposed solution is both effective and acceptable.

DNA Barcoding and Morphological Characters of Juvenile Plectropomus (Perciformes: Epinephelidae) Caught in Makassar Strait

Fri, 18 Jul 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

Integrated DNA barcoding and morphological variations can improve the identification of grouper species.
DNA barcoding confirms the morphological identification of Plectropomus (98-100% similar).
High intraspecies genetic diversity revealed within Plectropomus in Makassar Strait.
Potential cryptic species identified within Plectropomus based on genetic analysis.

Abstract

The high economic value of groupers has made them a popular choice in both local and international markets. However, identifying grouper species is also challenging due to complex morphological variations especially in the juvenile phase. An integrative approach combining DNA barcoding and morphometric analysis was applied to improve species identification accuracy and provide additional information on grouper stocks. This research aims to gain a deeper understanding of the morphological and genetic diversity of groupers caught in the juvenile phase from the Makassar Strait. Samples of the genus Plectropomus (n=6) collected from a fish landing site in Pangkajene Kepulauan Regency were identified based on morphology and using molecular methods (DNA barcoding). Phylogenetic and haplotype network analyses were performed. For all specimens the morphometric-meristic and molecular analyses were consistent (98-100% similarity) to known P. leopardus and P. oligacanthus accessions from GenBank. However, phylogenetic analysis: P. leopardus clustered into two distinct lower-level clades, and notably, two P. areolatus (Taiwan) resolved within the P. leopardus clade, while two P. laevis (Philippines) the resolved within the P. oligacanthus clade. Haplotype network showed high intraspecific genetic diversity, with P. leopardus forming four distinct haplotype groups and P. oligacanthus forming two groups. These findings collectively indicate that misidentification may be common and highlight the urgent need for further investigation into geographic barriers to gene flow and the potential existence of cryptic species or subspecies within Plectropomus. This study is expected to provide critical support for sustainable fisheries management and the conservation of marine biodiversity in the Makassar Strait.

In silico and In vitro Antibacterial Activity of Centella asiatica Leaves Bioactive Compounds Against Aquaculture Pathogenic Bacteria

Wed, 16 Jul 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

The GC-MS analysis of the asiatica leaves extracts identified 53 bioactive compounds.
The crude extracts of asiatica showed antibacterial efficacy against fish pathogenic bacteria.
13-Hexyloxacyclotridec-10-en-2-one has the potential to be an inhibitor of DNA gyrase.
Bioactive compounds derived from C. asiatica leaves extracts show potential as antibacterial agents.

Abstract

Antimicrobial agents are crucial for managing bacterial infections in fish cultures. Centella asiatica is a medicinal plant recognised for its diverse bioactive compounds with important antibacterial properties. The present study aimed to investigate the antibacterial activity of C. asiatica leaves bioactive compounds on fish pathogenic bacteria using an in vitro and in silico approach. The maceration method was used to extract bioactive compounds from C. asiatica leaves and was identified using Gas Chromatography-Mass Spectrometry (GC-MS). In vitro analysis of antibacterial activity was evaluated using the minimum inhibitory concentration method. While in silico molecular docking is applied alongside assessing Lipinski's rules of five, as well as absorption, distribution, metabolism, excretion, and toxicity properties. The result of the GC-MS examination of the C. asiatica leaf extracts identified 53 bioactive compounds. In vitro studies showed antibacterial efficacy of leaf extracts against fish pathogenic bacteria (Streptococcus agalactiae, Bacillus subtilis, and Staphylococcus aureus) with minimum inhibitory concentration values of 12,5 mg/ml. In silico molecular docking analysis showed that several bioactive compounds have the potential to be DNA gyrase inhibitors. Compound 13-Hexyloxacyclotridec-10-en-2-one has the highest inhibition with binding energy of −7,4 Kcal/mol compared to ciprofloxacin as drug standard with a binding energy value −7,3 Kcal/mol. The following compound is gamma.-Muurolene (−6,7 Kcal/mol), Copaene (−6,6 Kcal/mol) and Humulene (−6,6 Kcal/mol). These results suggest that bioactive compounds of C. asiatica leaves extracts hold promise as potential antibacterial agents for treating fish pathogenic bacteria infections.

Deep Learning Models Performance on Marine Fish Species Classification

Ezmahamrul Afreen Awalludin, Nur Muhammad Afiq Anang — Fri, 01 Aug 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

The ResNet50 presented the highest accuracy for classifying 20 marine fish species in the study.
The performance comparison demonstrated that ResNet50 outperformed both AlexNet and GoogLeNet.
Transfer learning enabled effective feature extraction from limited datasets.
Deep learning models offer potential for automating the classification of marine fish

Abstract

Identifying marine fish species accurately can be difficult due to their subtle anatomical and colour pattern similarities, which often result in misclassification during ecological assessments and fisheries operations. Manual identification methods are time-consuming and prone to errors especially in high throughput environments such as fish markets. In this study, transfer learning is used to evaluate three deep learning models ResNet-50, AlexNet and GoogLeNet on a total of 20,325 images from twenty marine fish species acquired from Kuantan (Pahang) and Mengabang Telipot (Kuala Nerus), Malaysia. All images were morphologically classified as complete fish, head, body and tail. The dataset was subjected to preprocessing procedures which encompassed image resizing, pixel normalization and data augmentation techniques that consists of random rotation (±15°), horizontal flipping, adjustments to brightness and contrast (±20%) and cropping. Subsequently, the dataset was partitioned into 80% training set (16,260 images), 10% validation set (2,032 images) and 10% testing set (2,033 images). The classification patterns were analysed using confusion matrices and standard metrics such as accuracy, precision and recall. ResNet-50 outperformed other models achieving ideal results with 100% accuracy, precision and recall in every category. With 99.5% and 99.4% accuracy, GoogleNet and AlexNet came in second and third, respectively. This study shows that deep learning models especially ResNet-50 achieved an accurate and efficient way to classify fish species automatically. With multi-view images, data augmentation and transfer learning, the model performs well even in difficult visual conditions. These results support its use in real-time fisheries monitoring, biodiversity studies, and environmental impact assessments

Identification of Hard Coral Disease (Scleractina) in Seribu Islands

Mon, 28 Jul 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

Coral colonies affected by coral disease are identified and counted.
White syndrome is a type of coral disease that is dominattly found.
Coral cover in the Kepulauan Seribu is in moderate condition.
A weak correlation between the prevalence of coral disease and live cover in the Kepulauan Seribu

Abstract

Kepulauan Seribu is designated as a marine conservation area in Kepulauan Seribu National Park and is one of high tourism development areas on the north side of Jakarta, the capital city of Indonesia. Anthropogenic sources from these nearby areas has reduced the health condition of coral reefs and increased the prevalence of coral diseases in the study area. This study aimed to determine the genus of coral infected by disease, the type of disease, and the relationship between the prevalence of disease and live cover in Kepulauan Seribu. Data was collected using the survey method. Coral cover is assessed using Underwater Photo Transect (UPT) and disease is assessed using Belt Transect methods, respectively. The result showed that 14 genera of coral species were infected and dominated by Porites, Montipora, and Acropora. Furthermore, there were 5 types of diseases, dominated by White Syndrome (WS), Atramentous Necrosis (AtN) and Ulcerative White Spots (S). The correlation analysis results showed a very low relationship between disease prevalence and live coral cover (r = 0.10). This research can be used as input or reference for more sustainable coral reef management, by improving an integrated coastal education system for the younger generation and developing more sustainable tourism activities in the future in Kepulauan Seribu.

Assessing the Population Parameters of Karumballichirus karumba (Poore and Griffin, 1979) from Intertidal Zone of Madura Strait

Abdul Qadir Jailani, Suradi Wijaya Saputra , Suryanti, Aninditia Sabdaningsih — Fri, 15 Aug 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

The Linf CL value in male karumba was 44.21 mm and female was 42.8 mm, with negative allometric growth.
The theoretical maximum lifespan (T_max) of individual karumba, estimated using the VBGF, was 4 to 6 years. The growth coefficient (K) K. karumba is considered quite slow between 0.5-0.9 per year.
The exploitation value of karumba is considered vulnerable at this time so that there is a need for management in terms of capture.
The results show that recruitment occurs almost every month. Estimated peak recruitment of karumba is around November and January.

Abstract

This study provides the first information on the population parameters of Karumballichirus karumba. A total of 902 K. karumba samples were collected, consisted of 412 males and 490 females. The von Bertalanffy parameters were estimated to have asymptotic length L∞ (mm): male = 44.21, female = 42.8, and pooled = 44, negative allometric condition factor, growth rate K (/years): male = 0.58, female = 0.67, and pooled = 0.9. Growth performance index (ϕ') : male = 3.05, female = 3.08, and pooled = 3.24. The natural mortality rate M (/years): male =0.7, female = 0.8, and pooled = 1, and shrimp mortality rate F (/years): male = 1.57, female = 2.89, and pooled = 3.12. The current exploitation rate is slightly higher than optimal exploitation rate = 0.5, indicating that there is a need to regulate fishing so that it is sustainable. The size of the first time caught is still below (1/2 Linf); thus, the reproductive opportunities of K. karumba are guaranteed, and in terms of utilization, fall into the category of sustainable fishing. The estimated life span of K. karumba is 4 to 6 years. Reproduction occurs continuously every month, indicated by the discovery of ovigerous females. The highest recruitment occurs in January and November. YPR (yield-per-recruitment) shows that the value of Fcur = 3.12 years⁻¹ in the estimated population is lower than Fmax = 5 years⁻¹ and above F05 = 1.99 years⁻¹ and F01 = 1.8 years⁻¹.

Biological Parameters and Stock Status of Crimson Snapper (Lutjanus erythropterus) in Indonesia FMA 712 based at Brondong Fishing Port

Adjeng Peni Listyanto Putri, Am Azbas Taurusman, Ronny Irawan Wahju — Thu, 07 Aug 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

This research highlight presents a focused summary of the key findings from our study in the field of fisheries science, specifically addressing the biological parameters and stock status of economically important fish species. There is highlighted research presented in this study, namely:

Crimson snapper in PPN Brondong is captured using four types of fishing gear: cantrang, jaring tarik berkantong, handline, and bottom longline.
The growth pattern of the crimson snapper is negative allometric.
The Gonad Maturity Level (GML) of the catch was predominantly composed of crimson snapper at GML I and GML II.
The asymptotic length (L∞) of crimson snapper was 47.68 cm, with K = 0.4 per year, total mortality (Z) = 2.44 per year, natural mortality (M) = 0.98 per year, capture mortality (F) of 1.55 per year, and exploitation rate (E) = 0.60
The estimated value of the crimson snapper SPR was 22% suggesting that the crimson snapper stock is ‘fully exploited’.

Abstract

The utilization status of crimson snapper stock in the Northern Java Sea (FMA 712) has reached optimum, tending to be over-exploited. This study aims to evaluate the stock status of crimson snapper (Lutjanus erythropterus) in FMA 712, especially in the northern waters of East Java. This research utilized catch data from the Brondong fishing port. The stratified random sampling method was utilized to collect samples at the research site. The findings indicate that the growth pattern of L. erythropterus exhibits a tendency towards negative allometry, with fishing mortality (F = 1.55) exceeding natural mortality (M = 0.89). The exploitation rate has reached a status of ‘fully exploited’ (E = 0.6). The Gonad Maturity Level (GML) of the catch is predominantly composed of GML I and GML II, suggesting that the majority of the captured fish have not yet spawned. It relates to the predominance of cantrang and jaring tarik berkantong, which capture fish of juvenile size. Thus, the Spawning Potential Ratio (SPR) parameter indicates it is ‘fully exploited’ (SPR = 0.22), i.e., the utilization rate has exceeded the limit of natural capacity for recruitment. This SPR value confirms: the utilization rate parameter (E), the fact that catch sizes tend to get smaller, and the results of previous studies in FMA 712. It is imperative to regulate the fishing efforts targeting the crimson snapper, as well as the deployment of cantrang and jaring tarik berkantong, which pose potential threats to the sustainability of this fishery.

Characteristics of Different Chitosan Types on κ-Carrageenan Polyelectrolyte Complex (PEC) Bioplastics as Food Packaging

Dhena Celia Haryadi Puteri, Mochammad Amin Alamsjah, Laksmi Sulmartiwi — Wed, 30 Jul 2025 00:00:00 +0700

Graphical Abstract

Highlights Research

1. This study investigates the impact of incorporating chitosan from different sources (shrimp, crab, and fish scales) with varying molecular weights on the mechanical characteristics of bioplastics used for food packaging.

2. The present study aims to optimize the volume ratio of κ-carrageenan and chitosan to form stable polyelectrolyte complexes (PECs) for bioplastic production.

3. This study evaluates the quality of tilapia fillets wrapped with κ-carrageenan and chitosan PEC bioplastics after 24 h storage.

4. The present study investigates the reaction mechanism involved in the formation of polyelectrolyte complexes between κ-carrageenan and chitosan for bioplastic production.

Abstract

Bioplastic represents an eco-friendly alternative to synthetic plastic and can be derived from natural polysaccharides like carrageenan. κ-carrageenan is noted for its gel-forming properties, making it a common raw material for bioplastics. Mechanical properties values of κ-carrageenan bioplastics are usually below standard. The addition of materials such as chitosan can enhance those properties. Chitosan-carrageenan can form polyelectrolyte complexe (PEC) through electrostatic interactions without toxic crosslinking agents. Polymer’s molecular weight is a crucial factor influencing PEC formation. Chitosan's molecular weight varies based on the raw material and extraction process. This study aims to identify the most suitable type of chitosan for food packaging bioplastics using polyelectrolyte complex (PEC) method. Three types of commercial chitosan with different molecular weights were evaluated (shrimp, crab, and fish scale chitosan). Japanese Industrial Standards (JIS) were used for characterization assessment of bioplastics such as thickness, tensile strength, water resistance, water vapor transmission, and biodegradation rate as well as additional tests including Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) analysis, and Total Plate Count (TPC) on fish fillets. The findings indicated that crab chitosan-κ carrageenan PEC bioplastic exhibited optimal results with a thickness of 0.178 mm, tensile strength of 18.053 MPa, elongation at break at 211.73%, water resistance of 63.94%, water vapor transmission (WVT) of 0,001456 g/m²/day, biodegradation rate of 3.358% over 7 days, and the lowest TPC in fish fillets after 24 h, increasing from 4.39 log CFU/g to 7.45 log CFU/g. Molecular weight of chitosan was shown to significantly influence the PEC bioplastics’ characteristics.

Uncovering Molluscs Diversity in Mandalika Coastal Through eDNA Metabarcoding

Thu, 07 Aug 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

The environmental DNA (eDNA) method successfully identified four species of molluscs (Monetaria , M. annulus, M. obvelata, and Phyllaplysia sp.) and two family taxa (Strombidae and Cypraeidae) from the seagrass and coral reef ecosystems on the Mandalika coast.
The species annulus, M. obvelata, and Phyllaplysia sp were detected in the coastal area of Mandalika for the first time using the eDNA approach, although they had never been recorded observationally in this area before.
The eDNA method is able to detect species that are difficult to observe directly, such as Phyllaplysia, which have never been reported in the coral reef ecosystem of Mandalika.
This study emphasizes the urgency of sustainable coastal area management with an eDNA-based scientific approach to monitor diversity, detect rare species, and evaluate the impact of human activities on the ecosystem.

Abstract

Molluscs are one of the main taxa in coastal ecosystems that play an important role in the food chain, bioindicators, and have high economic value. However, the limitations of conventional methods in detecting species that live hidden in complex ecosystems, such as seagrass and coral reefs, are a challenge in biodiversity monitoring. This study aimed to explore the diversity of mollusc species in the Mandalika coastal area using an eDNA metabarcoding approach. This study used the environmental DNA (eDNA) metabarcoding method to identify the diversity of molluscs in the coastal ecosystem of Mandalika, Central Lombok. The sites including Kuta Beach, Gerupuk Bay, and Aan Cape along the Mandalika coastal that contain both seagrass bed and coral reef ecosystems. Two samples were taken from each site in both the seagrass bed and coral reef ecosystems. Analysis of six water samples resulted in 99 ASVs and 116,611 final sequences, with 10 ASVs (50,960 sequences) identified as Mollusca taxa, all from the Gastropoda class. Four species were successfully identified, including Monetaria sp. M. obvelata, M. annulus and Phyllaplysia sp. that had not previously been reported through direct observation or conventional identification methods in Mandalika coastal area. Species diversity varied between locations and was influenced by environmental factors such as temperature, pH, salinity, phosphate, and anthropogenic pressure. These results show that eDNA metabarcoding is an effective tool in detecting mollusc species, even in hard-to-reach habitats, and support the urgency of scientific data-based mollusc conservation management.

A Filterable Agent Caused the Hemorrhagic Syndrome on Giant Gourami (Osphronemus goramy Lac.) at Yogyakarta

Nur Lailatul Fitrotun Nikmah, Murwantoko — Thu, 25 Sep 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

Yogyakarta reported a new disease outbreak that infected giant gourami (Osphronemus goramy Lac.) broodstock in several locations.
Typical clinical symptoms of the outbreak include bleeding and visceral adhesions.
The River’s postulate suggests that the cause of the outbreak is a filterable agent.
The filterable agent has the potential to be a new species or strain of the virus.

Abstract

Giant gourami (Osphronemus goramy Lac.) is one of the important freshwater fish commodities in Indonesia. Disease infection is one of the constraints in the production of this fish. There have been reports of disease outbreaks that caused mortality in giant gourami in several locations in Yogyakarta, including Gamping and Moyudan Districts, Sleman Regency; and Wates District, Kulon Progo Regency. This study describes the disease based on observations of external and internal signs, along with the histopathology of several tissues. Postulate river is used to prove the causative disease of the filterable agents. Polymerase Chain Reaction (PCR) and Reverse Transcriptase PCR (RT-PCR) are applied to confirm the presence of the virus. Sick fishes show the hemorrhage over the entire body surface, rotted fins, exophthalmia, petechiae, pale liver, visceral adhesions, and enlarged kidneys. Histopathological analysis shows lipidosis in the liver; bleeding in the liver, kidneys, spleen, and brain; and multiple necrosis in the kidneys, spleen, and brain. Based on these signs, we designated the disease to be Hemorrhagic Syndrome. The River postulate test confirmed that virus was the causative agent of the disease, as infecting healthy fish with a bacteria-free filtrate homogenate from diseased fish organs resulted in the same clinical signs observed in a natural outbreak. PCR tests for Megalocytivirus and EHNV, along with RT-PCR tests for VHSV, SVCV, TiLV, IHNV, and IPNV, did not show any DNA bands, indicating that these viruses were not present. A filterable agent, potentially representing a new virus species or strain, causes hemorrhagic syndrome in giant gourami.

Characteristics of Water-Soluble Collagen Extracted from Catfish (Pangasius sp.) Skin Using Different Acetic Acid (CH3COOH) Concentrations

Wed, 16 Jul 2025 00:00:00 +0700

Graphical Abstract

Highlight Research

Optimized extraction enhances fish skin-based collagen as an alternative to bovine and porcine sources.
Hydro-Extraction Advantage offer a cost-effective approach for producing high-purity, water-soluble collagen.
Varying CH₃COOH concentrations influence collagen yield and solubility, impacting its potential applications in food, pharmaceutical, and cosmetic industries.
Hydro-extracted collagen is biodegradable and free of harmful residues.

Abstract

Collagen extraction from fish skin offers a sustainable approach to valorize fish processing by-products, and fish skin catfish (Pangasius sp.) is recognized as a promising collagen source. However, previous studies reported that in low water solubility, limiting its functional application in food, pharmaceutical, and cosmetic industries. To address this challenge, this study investigates the use of varying acetic acid concentrations (0.4, 0.6, and 0.8 M) during the hydrolysis stage prior to hydro-extraction, aiming to enhance the solubility and quality of the extracted collagen. Parameters measured included yield, solubility, proximate composition (protein, fat, air content, ash), organoleptic quality, molecular weight, amino acid profile and functional groups analysis. The best results were achieved with 0.6 M acetic acid, resulting in type I collagen coupled by the amide groups A, B, I, II, III, and molecular weights (65, 95, 130 and 270 kDa). The dominant amino acids identified was glycine. This treatment yielded a collagen extraction rate of 9.04% and solubility of 79.71%. The proximate composition included 67.34% protein, 14.87% fat, 8.48% moisture, and 10.69% ash. Organoleptic scores for appearance, odour, and texture were 7.80, 7.93, and 6.80, respectively. The collagen met the SNI 8076:2020 standard for protein content, moisture, and organoleptic attributes; however, fat and ash contents exceeded the specified limits. In conclusion, the acetic acid concentration significantly affects the physicochemical and sensory properties of collagen. Catfish skin shows strong potential as a raw material for collagen production, which supports its use in the food, pharmaceutical, and cosmetic sectors.

Evaluation of AMPEP as a Natural Biostimulant for Enhancing Biomass and Pigment Yield in Chlorella sorokiniana

Mon, 22 Sep 2025 00:00:00 +0700

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Chlorella sorokiniana achieved the highest cell density, growth rate, and biomass at 100 mg L⁻¹ AMPEP.
100 mg L⁻¹ produced the largest cells, while higher concentrations (150–200 mg L⁻¹) reduced cell density due to nutrient imbalances.
150 mg L⁻¹ AMPEP maximized chlorophyll a and carotenoid accumulation, enhancing pigment production
AMPEP demonstrated potential as a natural biostimulant to enhance microalgal productivity for biotechnological applications.

Abstract

Chlorella sorokiniana is a promising microalga valued for its production of pigments, lipids, and proteins with potential applications in biofuels, nutraceuticals, and pharmaceuticals. However, enhancing its growth and productivity remains a key challenge. Acadian Marine Plant Extract Powder (AMPEP), derived from the brown seaweed Ascophyllum nodosum, is known for its growth-promoting and stress-resistance properties in plants, but its effects on microalgae are not well understood. This study aimed to evaluate the effects of different concentrations of AMPEP (50, 100, 150, and 200 mg L⁻¹) on the growth, biomass, and pigment accumulation of C. sorokiniana. The experiment was conducted using a completely randomized design with five treatments (including a control) and three replicates per treatment. The results showed that 100 mg L⁻¹ AMPEP produced the highest cell density, with a 2.50-fold increase compared to the control, and the highest specific growth rate of 0.17 ± 0.03 day⁻¹. The largest cell size (19.51 ± 0.77 µm) was recorded at 200 mg L⁻¹, while biomass production peaked at 6.41 ± 0.49 g L⁻¹ with 50 mg L⁻¹. Maximum chlorophyll a and total carotenoid content were observed at 150 mg L⁻¹. Overall the 100 mg L⁻¹ AMPEP is the most balanced and optimal concentration overall for growth enhancement of C. sorokiniana, while other concentrations may be selected based on specific objectives like pigment or biomass production. These findings suggest that AMPEP, particularly at moderate concentrations, can significantly enhance the growth, biomass yield, and pigment content of C. sorokiniana. Further research is recommended to investigate the underlying mechanisms of AMPEP’s biostimulant effects and its potential application in large-scale algal cultivation systems.

Reduction of Raoultella ornithinolytica TN5 Biofilm using Hot Water and Nanochitosan

Mon, 28 Jul 2025 00:00:00 +0700

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The biofilm formation of Raoultella ornithinolytica on a stainless steel surface was analyzed
Longer duration of hot water immersion leading to a higher reduction of Raoultella ornithinolytica biofilm on stainless steel surface.
Longer duration of nanochitosan exposure leading to a higher reduction of Raoultella ornithinolytica biofilm on stainless steel surface
The combination treatment of hot water immersion and nanochitosan shows higher efficacy to reduce Raoultella ornithinolytica biofilm on stainless steel surface compare to sodium hypochlorite treatment.

Abstract

The equipment surfaces in food processing industries have the potential to contaminate products. Bacteria on a surface are able to form a biofilm. This study aimed to determine the effect of a combination treatment using hot water immersion and nanochitosan on the reduction of R. ornithinolytica’s biofilm on stainless steel surfaces. R. ornithinolytica was applied to a stainless steel surface, incubated at 30^oC for 48 hours, and tested for its reduction using hot water immersion treatment with different times. The best result from this treatment was when it was used in combination. The viability of cells was determined using a swab and the total plate count method. A scanning electron microscope was used for qualitative observations of biofilm formed on stainless steel before and after sanitation. The result showed that 10 minutes of hot water immersion resulted in significant R. ornithinolytica biofilm reduction compared to 5 minutes of treatment (p<0.05). Furthermore, the combination treatment of 10 minutes of hot water with 15 minutes of nanochitosan (0.1%) immersion showed the highest percent reduction of R. ornithinolytica biofilm (p<0.05). The ability of the combination treatment to eliminate R. ornithinolytica biofilms is equivalent to or even better than sodium hypochlorite treatment.

Spatio - Temporal Distribution of Nitrate and Phosphate in Serayu Watershed, Central Java, Indonesia

Wed, 23 Jul 2025 00:00:00 +0700

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First study to analyze the three-year spatiotemporal distribution of nitrate and phosphate in the Serayu River Basin.
Reveals seasonal and spatial nutrient hotspots linked to agricultural runoff and domestic activities.
Identifies strong correlations: nitrate with TSS and COD (2021), and phosphate with COD (2021–2022) and pH (2023).
Supports integrated watershed management through evidence-based nutrient pollution assessment using PCA and spatial mapping.

Abstract

The Serayu Watershed is a vital area in Indonesia, where agricultural runoff contributes to nutrient enrichment in rivers. This study offers novelty as it is the first to analyze the spatiotemporal distribution of nitrate and phosphate in the Serayu River over a three-year period (2021–2023). The research aims to support sustainable watershed management by examining nutrient dynamics and their correlation with environmental parameters such as dissolved oxygen (DO), pH, total suspended solids (TSS), and chemical oxygen demand (COD). Water sampling was conducted at 15 stations across upstream, midstream, and downstream segments. Data were analyzed using Microsoft Excel and PAST 4.03, applying Principal Component Analysis (PCA) and biplot methods. Results showed nitrate levels were highest downstream in 2021, but shifted upstream in 2022–2023, likely due to organic matter decomposition. Phosphate remained highest midstream throughout the period, linked to domestic activity and land use. Nitrate levels fluctuated seasonally, especially during the rainy season, while phosphate levels were relatively stable. Spatial mapping highlighted dynamic nitrate changes in Banjarnegara and Cilacap, with phosphate distribution remaining more uniform. Correlation analysis revealed nitrate was related to TSS and COD in 2021, had no significant correlation in 2022, and was linked with pH in 2023. Phosphate consistently correlated with COD and pH. These findings emphasize that both natural and human-induced factors drive nutrient variability in the Serayu watershed, underlining the urgency of integrated watershed management to control nutrient pollution and protect water quality.

Physical Degradation of Toli Shad Gillnet: Breaking Strength, Elongation, and Fisheries Implications

Thu, 24 Jul 2025 00:00:00 +0700

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Synthetic nets, widely used in aquaculture and marine fishing, experience reduced performance over time due to environmental exposure.
The study analyzes the effectiveness of Toli shad gillnets based on their technical age using statistical and experimental methods.
A strong negative correlation exists between technical age and both breaking strength (r = -0.972) and elongation (r = -0.92).
Toli shad gillnets perform optimally within 2 to 3 years of use, with effectiveness declining by the fourth year as indicated by scores of 40–59, suggesting adequate performance but the need for targeted improvements.
Medium-term maintenance should be performed annually throughout the net’s service life, up to a maximum of 7 years, while replacement is recommended starting in the 4 year to mitigate performance degradation.

Abstract

Synthetic nets have high elasticity and are widely used for both aquaculture and marine fishing. However, as their technical age increases, their performance declines due to wear, reduced breaking strength, and decreased elongation caused by continuous exposure to the marine environment. Monitoring the technical age of nets is crucial to maintaining the effectiveness of Toli shad gillnets, minimizing losses, and ensuring optimal catch yields. This study aims to examine the physical degradation of synthetic gillnets used in Toli shad (Tenualosa macrura) fisheries based on their technical age. This study utilized gillnets targeting toli shad (Tenualosa macrura), with varying technical ages (control net, 1-year, 2-year, and 3-year nets), all made from polyamide (PA) monofilament. The differences in net dimensions were attributed to variations in their service life. The method used is purposive sampling, analyzed using descriptive statistics, correlation analysis, a Completely Randomized Design (CRD), and effectiveness evaluation. The results show that the structure of Toli shad gillnets consists of mesh sizes of 77.82–99.60 mm, thread diameters of 0.34–0.53 mm, and knot heights of 1.52–2.28 mm. The relationship between technical age and breaking strength has a correlation coefficient (r) of -0.972, an R² of 0.94, and a regression equation of y = 9.85 - 1.31x. The LSD test indicates a significant difference in breaking strength across treatments. The correlation between technical age and elongation has an r-value of -0.92, an R² of 0.86, with the equation y = 20.11 - 0.34x. The LSD test shows that the control net has significantly different elongation compared to others, but nets aged 1, 2, and 3 years show no significant differences. The study concludes that Toli shad gillnets remain effective for up to 3–4 years, with an effectiveness value of ≥50%. The implications of this study contribute to the efficient management of fishing nets by informing maintenance and replacement strategies based on the technical age and mechanical degradation of the gear. These findings suggest the importance of integrating net lifespan into gear management to enhance catch performance and sustainability in small-scale fisheries.

Seagrass Ecosystem Assesment for Dugong Conservation: Integrating Anthropogenic Activites and Oceanographic Parameters in East Java’s Coastal Waters

Fri, 25 Jul 2025 00:00:00 +0700

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1. The study successfully identified the utilization of coastal and marine areas within the research site.

2. Oceanographic parameters across the study area have been analyzed, providing insights into variations in environmental conditions favoring seagrass ecosystem resilience.

3. The structure of seagrass vegetation has been thoroughly observed, revealing differences in species composition, density, and coverage.

4. Furthermore, the study establishes the connectivity between coastal and marine spatial utilization, oceanographic factors, and seagrass ecosystem dynamics, highlighting their interdependent relationships.

Abstract

This study aims to assess the ecological status of seagrass meadows and their relationship with dugong (Dugong dugon) habitats across four distinct ecological regions in East Java, Indonesia. Field assessments were conducted to evaluate seagrass community structure, oceanographic parameters, and the intensity of human activities. Seagrass distribution was mapped using Sentinel-2A satellite imagery, while seagrass health was evaluated through the Seagrass Ecological Quality Index (SEQI) and Importance Value Index (IVI). Statistical analyses, including Analysis of Variance (ANOVA) and Principal Component Analysis (PCA), were employed to identify significant differences and key environmental drivers. The results revealed marked spatial variation in oceanographic characteristics and seagrass coverage (p < 0.05). PCA showed that anthropogenic factors—particularly marine space utilization such as aquaculture and coastal development—were major contributors to seagrass degradation. Elevated nutrient concentrations were also associated with declining seagrass health, indicating land-based pollution as a dominant stressor. These findings underline the urgent need for integrated coastal zone management. Strengthening conservation policies, reducing terrestrial runoff, and implementing sustainable marine spatial planning are critical to safeguard seagrass ecosystems and ensure the long-term survival of dugong populations in Indonesian waters.