Journal of Fisheries and Environment

Aquafeed Innovation: Utilization of Insects for Sustainable Fish Nutrition: A Review

2025-10-16T14:45:03+07:00

Rapid global population growth has increased food demand, placing pressure on conventional agriculture and highlighting the need for sustainable protein sources. Aquaculture contributes significantly to global food security by supplying animal protein, yet its expansion is constrained by the high cost and environmental impact of traditional feed ingredients such as fishmeal and soybean meal, which are associated with overfishing and deforestation. These challenges have encouraged the exploration of alternative, environmentally responsible feed resources. Insects have emerged as a promising ingredient in aquaculture diets due to their high-quality protein, balanced amino acid profile, and beneficial lipid composition. Insect-based meals offer economic advantages while reducing reliance on conventional feed sources, potentially improving both sustainability and resource efficiency within the sector. This review evaluates the nutritional benefits and environmental implications of incorporating insect-derived ingredients into aquafeeds and examines their potential to enhance sustainable aquaculture production. The review also discusses key barriers to large-scale adoption, including regulatory limitations, cultural acceptance, production scalability, and logistical challenges. Safety considerations such as microbial risks, allergenic potential, and the accumulation of undesirable substancesare analyzed within current regulatory frameworks. Additionally, existing knowledge gaps, species-specific responses, digestibility concerns, and optimal inclusion levels are addressed, alongside consumer perception and market acceptance. Overall, continued research, investment, and supportive policy development are essential to facilitate the integration of insect-based feeds into mainstream aquaculture. Advancing these efforts can support environmentally sustainable aquaculture practices while helping meet the growing global demand for protein.

Assessing the Accuracy of Sentinel-2A and the Van Hengel-Spitzer Algorithm for Bathymetry Mapping in Shallow Waters: A Case Study of Bokori Island, Indonesia

2025-09-03T14:39:57+07:00

Multispectral remote sensing is a proven tool for mapping shallow waters, but accurately capturing seabed color signatures remains a significant challenge due to water- column effects, atmospheric interference, and complex interactions between inherent and apparent optical properties. Our study explores whether Sentinel-2A satellite imagery, processed with the Van Hengel-Spitzer (VHS) algorithm, offers a practical solution for bathymetric mapping. We collected field depth measurements using echo-sounders and adjusted these for tidal variations. Applying the VHS algorithm generated relative depths, which we then calibrated to absolute depths using a linear regression model based on our in-situ data. The results are promising: the combined VHS and Sentinel-2A approach delivered robust depth estimates down to 12 meters. The relationship between satellite-derived depths and in situ measurements was strong (R² = 0.683). When we tested accuracy, nearly 80% (79.66%) of the satellite estimates fell within ±3 meters of the actual depths. The data also showed higher precision, with 54.24% of estimates accurate within ±2 meters and 32.2% within just ±1 meter of the measured depths. These findings confirm that Sentinel-2A provides a viable option for moderately accurate, efficient bathymetric mapping in clear, shallow marine environments. This approach holds significant potential for supporting coastal zone management and environmental monitoring efforts.

Effects of Feed Type, Temperature and Light Conditions on Rearing Performance of Ornate Spiny Lobster (Panulirus ornatus) Phyllosoma Larvae in Thailand

2026-02-23T15:49:49+07:00

The ornate spiny lobster Panulirus ornatus is a valuable but challenging aquaculture species, with larval survival—particularly of the phyllosoma stage—being a primary constraint. This study evaluated the effects of feed types and environmental conditions (light and temperature) on feeding performance and survival of primary phyllosoma larvae. Results show that providing appropriate live feed significantly enhances nursery performance (p<0.05). Larvae in the 1^st P stage fed Artemia nauplii (AN) exhibited the highest mean survival from day 3, surpassing those fed with S-type rotifer (SR) or a mixed AN+SR regime. In the absence of feeding, survival dropped with complete mortality by day 7. Notably, 1^st P larvae fed exclusively on AN demonstrated the longest survival duration. In contrast, artificial feed (AF) yielded a lower survival, with all individuals dying within 7 days, and combined AN+AF survival remaining below 15 days. Temperature profoundly affected feeding and mortality: at 30 °C, Artemia intake peaked (9.9 individuals·day^-1) with the lowest mortality (12.56 %·day⁻¹), whereas 33 °C produced the highest daily mortality. Light conditions did not significantly influence daily feeding or mortality rates. Collectively, these findings advance understanding of factors governing 1^st P survival and offer evidence-based guidelines to optimize larval rearing and future productivity of P. ornatus.

Size Variation and Survival after Transplantation of the Tropical Box Marine Mussel Septifer bilocularis on the Three Coastal Sites of North Sulawesi, Indonesia

2025-12-17T15:53:35+07:00

Box mussels exhibit patchy distribution patterns across intertidal and subtidal zones, where environmental contrasts strongly influence their physiology and ecology. Intertidal box mussels experience frequent air exposures, variable salinity, acidity, and turbidity during low tide, whereas subtidal mussels generally experience more stable conditions. However, with rising sea temperatures related to global climate change, these stressors may intensify, disrupting the mussel’s activities. Consequently, their roles in marine ecosystems may change, yet knowledge of box mussel responses to environmental change remains limited. This study investigated the effects of site, time (monthly intervals), and position (intertidal vs. subtidal) on mussel growth and survival. Box mussels were transplanted to intertidal and subtidal seabeds at three sites in North Sulawesi: Tiwoho, Tongkaina, and Blongko, from August to November 2023. Shell length and survival rates were analyzed using a three-way ANOVA, with site, time, and position as main factors. The results showed that mean shell length was significantly influenced by all three factors. The box mussels grew rapidly from August to September, followed by slower growth from October to November. The final mean size was higher at Tongkaina compared to Blongko, while Tiwoho did not differ significantly from Tongkaina. Survival declined steadily, averaging 22–40% by November, and was influenced by time and position but not by site. Ascidians were observed attaching to the cages in November. Seawater temperature, ascidian presence, and food availability may influence mussel size and survival. Finally, although the tropical mussel, S. bilocularis, exhibits higher thermal tolerance, it remains vulnerable to ocean warming.

Size Selection of Short-necked Clam (Paphia undulata) Dredge in Thai Waters: An Application of Selectivity Model to Improve the Fishery Management

2025-11-17T18:16:40+07:00

The short-necked clam (Paphia undulata) has been a commercially important marine species throughout the Indo-Pacific region for centuries. Recently, the sieve sizes of the short-necked clam dredge still need to be reconsidered by fishery managers and stakeholders to ensure the sustainability of this resource. This study aimed to (i) review the short-necked clam fisheries in Thailand, (ii) apply a parametric selectivity model to the short-necked clam dredge, and (iii) assess the catches to determine the suitable sieve size based on size selectivity, maturity size, and marketable size. This study reviewed and analyzed secondary data, including fishery statistics, fishing gears and operations, short-necked clam dredge experiments, and information on maturity and marketable sizes. Our findings indicated that short-necked clam fishery in Thailand dates back to the 19^th century, evolving from hand-collecting to dredging by fishing vessels both in the Gulf of Thailand and the Andaman Sea. The parametric model was applied to three different sieve sizes (8 mm, 10 mm, and 12 mm) to enhance the precision of size selectivity estimation. The results revealed that the shell length selectivity of the short-necked clam dredge was 26.0 mm, 30.0 mm, and 36.5 mm for the 8 mm, 10 mm, and 12 mm sieve sizes, respectively, with an estimated selection factor of 3.20. The catch assessment demonstrated that a 10 mm or larger sieve size is optimal for reducing the capture of immature and unmarketable short-necked clams and supporting effective fishery management and sustainable resource utilization.

Effects of Stocking Density on Fish and Rice Yields in Semi-intensive Rice-fish Culture of Climbing Perch (Anabas testudineus) in Rain-fed Rice Paddies

2026-01-23T19:27:57+07:00

We investigated the feasibility of culturing air-breathing carnivorous fish, climbing perch (Anabas testudineus), in a semi-intensive rice-fish system in Northeast Thailand. Fingerlings of two initial size classes (ca. 1 and 6 g per fish) were reared for 2.5 or 3.5 months to evaluate the effects of stocking density (0–80 fish∙m⁻²) on fish growth, fish yield, and rice yield. Fish reached market size (100 mm total length and 20 g wet weight) at all stocking densities. Total fish yield increased proportionally with stocking density, at least up to 60 fish∙m⁻², yielding 1.8–2.0 kg∙m⁻², indicating that climbing perch did not experience density-related constraints within this range. Trade-off existed between fish and rice yields, with rice yield declining significantly at stocking densities of ≥20 fish∙m⁻²(mean: 200 g∙m⁻²) compared to the no-fish control and 10 fish∙m⁻²treatments (mean: 520 g∙m⁻²). Fish revenue was comparable to, or slightly lower than, the combined costs of fingerling purchase and feed under concurrent culture conditions, with fingerling costs accounting for nearly 40% of this production cost. Overall, this study demonstrates that semi-intensive rice-fish culture of climbing perch is feasible in terms of fish production; however, further optimization of culture conditions is necessary to sustain both fish and rice yields at higher stocking densities. Specifically, extending the culture duration and/or improving fish growth performance are necessary to enhance profitability.

Hermit Crabs of the Family Diogenidae Ortmann, 1892 (Crustacea: Decapoda: Anomura) in Indonesia: Diversity, Distribution and Habitat

2025-08-05T17:32:22+07:00

Hermit crabs of the family Diogenidae are ubiquitous organisms along the coasts of the Indonesian archipelago. This study aims to contribute additional data to enhance the current understanding of the geographical distribution patterns, bathymetric distribution, and habitat preferences of diogenid hermit crab species within the framework of Indonesia’s marine ecoregions. Distributional data of Diogenidae in Indonesian waters were obtained from scientific literature, dissertations, and unpublished Museum Zoologicum Bogoriense (MZB) specimen data. The diversity analysis of the family Diogenidae in Indonesia identified 116 species in 13 genera. These hermit crabs are widely distributed throughout the country, occurring in all 12 previously defined marine ecoregions. They are found across a broad depth range, and most species are found in more than one substrate such as rocky shores, sand flats, and muddy bottoms, as well as ecosystems including seagrass beds, mangroves, and coral reefs. Seventy percent of species inhabit the littoral zone, which extends from 0 to a depth of 50 m. Among the species studied, Paguropsis andersoni exhibited the broadest vertical distribution, ranging from the littoral zone down to the bathyal zone, with recorded depths between 30 and 548 m. The genera Diogenes and Clibanarius comprise the highest number of species, with 27 and 26 respectively. Among the ecoregions analyzed, the Banda Sea shows the greatest species richness, with a total of 66 identified species of Diogenidae. The most commonly found species in Indonesian waters is Clibanarius striolatus.

Enhancing Water Quality in Intensive Asian Seabass (Lates calcarifer) Aquaculture Using Green Mussels (Perna viridis): A Biomass‒Normalized Apparent Reduction

2026-01-09T16:01:44+07:00

Integrated multi‒trophic aquaculture (IMTA) is a promising strategy to mitigate water quality deterioration in intensive marine aquaculture, although continuous water renewal may obscure the role of extractive species. This study evaluated green mussel (Perna viridis) integration with Asian seabass (Lates calcarifer) under simulated marine IMTA conditions. A 60-day experiment with four mussel biomass treatments was conducted at constant seabass density, with routine water exchange (50% every three days). Key water quality parameters, including dissolved oxygen (DO), temperature, power of hydrogen (pH), salinity, total ammonia nitrogen (TAN), nitrite‒nitrogen (NO₂^-‒N), nitrate‒nitrogen (NO₃⁻–N), alkalinity (ALK), total suspended solids (TSS), and turbidity, were monitored throughout the experiment. Asian seabass growth performance, survival, and biomass production were also assessed. Mussel‒integrated treatments showed significantly lower concentrations of ALK, TAN, TSS, and turbidity, along with higher NO₃⁻–N, compared with the control (p<0.05), whereas DO, temperature, pH, NO₂^-‒N, and salinity did not differ significantly among treatments. Despite identical water‒exchange regimes, the presence of mussels contributed to improved water quality stability. Fish growth, survival, and biomass production were enhanced in mussel‒integrated systems, particularly at intermediate to high mussel biomass. These results demonstrate that green mussels can enhance water quality and production performance in intensive Asian seabass culture beyond the effects of routine water exchange alone, supporting the application of biomass‒based IMTA as a practical approach for sustainable marine aquaculture.

Effect of Salinity Differences on Growth and Chlorophyll a Content in Caulerpa racemosa

2025-11-09T14:25:41+07:00

Caulerpa racemosa (sea grapes) is a commercially valuable green macroalga widely cultivated in Indonesia for its nutritional and economic potential. Salinity is among the most critical environmental factors governing its growth and photosynthetic pigment production, yet the optimal salinity range for Indonesian pond cultivation systems remains poorly defined. This study aimed to determine the effect of different salinities on the growth and chlorophyll a content of C. racemosa and to identify the salinity level that best supported its growth and chlorophyll a content. This study used an experimental method with a Completely Randomized Design (CRD) consisting of four treatments and three replications: S24 (24 ppt), S27 (27 ppt), S30 (30 ppt), and S33 (33 ppt). The C. racemosa cultivation system used the off-bottom method, with an initial weight of 50 g and a water volume of 12 L and was maintained for 43 days. The collected data included morphological observations, absolute growth, specific growth rate (SGR), chlorophyll a content, and water quality. The results showed that salinity had a significant effect (p<0.05) on absolute growth, SGR, and chlorophyll a content, with the highest values observed in treatment S27. Based on the study, the S27 treatment (27 ppt) produced the highest absolute growth (133.28±16.26 g), SGR (3.01±0.21 %·day⁻¹), and chlorophyll a content (452.16±0.19 µg·mL⁻¹), indicating that maintaining salinity around 27 ppt can optimize physiological performance and enhance biomass yield in C. racemosa cultivation.

Genomic Characterization and Hydrolysis Enzyme of Piscibacillus salipiscarius RBU1-1ᵀ and Allobacillus salarius SKP4-8ᵀ Isolated from Fermented Fish Products

2026-01-27T15:11:44+07:00

Two halophilic bacterial strains, Piscibacillus salipiscarius RBU1-1ᵀ and Allobacillus salarius SKP4-8ᵀ, were isolated from traditional Thai fermented foods, namely pla-ra from Ratchaburi, Thailand, and ka-pi from Samut Sakhon, Thailand, respectively. Comparative genomics confirmed their taxonomic distinctiveness, with RBU1-1ᵀ representing a novel species and SKP4-8ᵀ showing clear genomic separation from its closest relatives. The draft genomes were 2.99 Mb (36.7 mol% G+C) for RBU1-1ᵀ and 2.59 Mb (38.8 mol% G+C) for SKP4-8ᵀ. Both strains encoded hydrolytic enzymes and secondary metabolite pathways, with SKP4-8ᵀ displaying higher protease activity and RBU1-1ᵀ harboring ectoine biosynthetic and stress-response genes. RBU1-1ᵀ encoded the biosynthesis pathways for ectoine, tryptophan, and thiamine, while SKP4-8ᵀ encoded thiamine, riboflavin, coenzyme A, and menaquinone, indicating their potential contributions to postbiotic and nutritional value. Safety assessment revealed the absence of biogenic amine, antibiotic biosynthesis, and major virulence genes in both strains. Although antimicrobial resistance-associated genes were detected, no complete clusters were identified, suggesting low phenotypic risk. Computational pathogenicity prediction indicated a low probability for RBU1-1ᵀ (0.242) and a higher probability for SKP4-8ᵀ (0.945), though these require cautious interpretation. Overall, genomic evidence and enzymatic activity support RBU1-1ᵀ and SKP4-8ᵀ as safe, functional starter culture candidates, with RBU1-1ᵀ showing strong potential through postbiotic biosynthesis and SKP4-8ᵀ through proteolytic activity.

Evaluation of Fermented Azolla (Azolla pinnata) Extract as an Alternative Nutrient Medium for Spirulina (Limnospira platensis) Culture

2025-09-20T12:25:58+07:00

Limnospira platensis (Gomont, 1892) Roussel et al., 2023, formerly known as Spirulina platensis or Arthrospira platensis and hereafter referred to as ‘spirulina’ in this study, is a filamentous cyanobacterium with high nutritional value. It is widely used as a dietary supplement for humans and as a feed supplement for animals. Kosaric medium (KM) is the most widely used commercial medium for Spirulina sp. production; however, it incurs high production costs. This study aimed to evaluate fermented Azolla pinnata extract medium (FAEM) as a cost-effective alternative medium for spirulina culture. Growth, pigmentation, and protein content of spirulina were evaluated under a partial substitution design in which KM was replaced by FAEM at 25, 50, 75, and 100%, with 100% KM used as the control. Maximum dry cell weight (143.5±11.97 mg·L^-1), optical density (1.54±0.08), specific growth rate (0.49±0.03 day^-1), chlorophyll a (6.54±0.04 μg·mL^-1), and β-carotene (2.93±0.04 μg·mL^-1) of spirulina were observed in KM, while comparable results were obtained in FAEM25. However, all growth parameters gradually decreased as the FAEM concentration increased. The protein content of spirulina was significantly (p<0.05) higher in FAEM25 (65.6%) than in the other FAEM treatments and KM (59.4%). Total nitrogen and organic carbon contents were higher in FAEM (8640 ppm and 0.023%, respectively) compared to KM (5760 ppm and 0.015%, respectively). The medium cost of FAEM25 (0.18 USD·L^-1) was lower compared to KM (0.25 USD·L^-1). Therefore, FAEM25 can serve as a cost-effective alternative medium for spirulina cultivation, improving protein content while maintaining growth or pigmentation comparable to those obtained in KM.

Interactive Influence of Stocking Density and Dietary L-Tryptophan on Growth Performance, Physiological Responses and Cannibalism in Striped Snakehead (Channa striata) (Bloch, 1793)

2026-01-12T11:23:42+07:00

A -day experiment was conducted to investigate the interactive effects of stocking density and dietary L-tryptophan on the growth performance and physiological responses of striped snakehead (Channa striata) during the nursery rearing period. Advanced fry (0.32±0.293 were randomly stocked in 36 glass aquaria in a 3×4 factorial design, with three stocking densities (375, 500, and 625 fish·m⁻³) and four dietary L-tryptophan levels (0%, 1%, 2%, 3%). Each treatment was triplicated. Results ed that fry reared at 375 fish⸳m⁻³ and fed 3% L-tryptophan had significantly higher weight gain (4.67±0.04 g), specific growth rate (4.68±0.09%·day⁻¹), and feed efficiency ratio (1.33±0.02), as well as lower feed conversion ratio (0.75±0.02) and cannibalism (26.7±0.30%) than other groups. This treatment also produced higher RBC (4.07±0.05), Hb (9.76±0.25), Ht (35.1±0.32) and greater digestive enzyme activities, including protease, lipase, and amylase. Higher espiratory burst activity (0.41±0.01) was recorded at 375 fish⸳m⁻³ with 0% L-tryptophan, while highest antioxidant enzyme activities, catalase and superoxide dismutase, were observed at 625 fish⸳m⁻³ with 3% L-tryptophan. Survival rate (69.93±1.11%) was observed at 375 fish⸳m⁻³ with 3% L-tryptophan. No abnormalities were observed in the intestine or liver of L-tryptophan fed groups, whereas severe hepatocyte vacuolations were observed in control. Therefore, 375 fish⸳m⁻³ with 3% L-tryptophan is the ideal combination for improving growth, health performance and survival while reducing stress and cannibalism.