Aquaculture, Aquarium,
Conservation & Legislation

The integration of fish farming and vegetable farming is a promising approach for utilizing fish farm effluents, which are rich in nitrogen, phosphorus, and potassium, while diversifying food production in agroaquaculture systems in West Africa. This study evaluated the effect of three stocking densities of Nile tilapia (Oreochromis niloticus) fingerlings, namely D1 (40 fingerlings m⁻³), D2 (60 fingerlings m⁻³), and D3 (80 fingerlings m⁻³), each tested with three replicates, on the zootechnical performance of the fish after 75 days of rearing, on the physicochemical quality of the effluent, and on the agronomic performance of lettuce (Lactuca sativa, 56 days) and tomato (Solanum lycopersicum, 70 days) grown in an integrated system. The results show that the average final weight, average daily gain, survival rate, and specific growth rate of the fish decreased significantly in D3 compared to D1 and D2 (p < 0.05), while the feed conversion ratio increased, reflecting a decline in feed efficiency at high stocking densities. At the same time, the concentrations of non-ionized ammonia, nitrite, nitrate, and potassium in the effluent increased significantly and almost linearly with stocking density (r = 1.00 for nitrate), without any notable change in temperature, pH, or dissolved oxygen. From an agronomic perspective, lettuce yield did not vary significantly across stocking densities (p > 0.05) but reached its maximum at D2. For tomato, the number of fruits, average fruit weight, total weight harvested per plant, and plant height were significantly higher at D2 than at D1 (p < 0.05). Density D2 (60 fingerlings m⁻³) thus appears to be the optimal compromise between fish production and vegetable production, ensuring sufficient enrichment of the effluent with assimilable nutrients without compromising fish growth or survival. These results provide a scientific basis for optimizing integrated systems in tropical regions and for the circular utilization of fish farm effluent in vegetable farming.

The increasing demand for aquaculture production under limited land availability requires efficient intensive culture systems. This commercial case study evaluated the production performance and economic viability of whiteleg shrimp, Penaeus vannamei Boone, 1931, cultured in an HDPE-lined circular tank system under commercial farm conditions across three sequential production cycles with progressively increasing stocking densities (318-467 ind m⁻²). Progressive intensification was associated with higher biomass production, increasing total biomass from 1,500 to 2,015 kg and yield from 4.78 to 6.42 kg m⁻². However, this was accompanied by a decline in survival (94-80%) and a slight increase in feed conversion ratio (FCR) (1.20-1.29), indicating trade-offs between production and biological performance. Most water quality parameters remained within acceptable ranges throughout the culture period, although total ammonia nitrogen (TAN) increased across successive production cycles as stocking density increased. Despite higher production costs, economic performance improved, with net profit increasing from USD 2,852.80 to USD 4,730.17 and return on investment (ROI) from 58.78% to 66.61%. Annual production reached 5,300 kg, with an overall ROI of 63.63% and a benefit-cost ratio of 1.64. These findings suggest that HDPE-lined circular tank systems can support profitable intensive shrimp production under space-limited conditions when supported by appropriate feeding, aeration, and water quality management. Because the study was conducted in a single commercial production system using sequential, non-replicated production cycles, the findings should be interpreted as operational observations rather than definitive evidence of stocking density effects. Further replicated studies are needed to determine the optimum stocking density for maximizing productivity, economic returns, and biological performance.

This study aimed to examine the effect of papaya (Carica papaya) leaf extract in feed on the growth performance, feed efficiency, and body nutrient composition of Java barb (Barbonymus gonionotus) at the grow-out stage. The study used a completely randomized design with four treatments and three replicates. The test fish were Java barb at the grow-out stage with an average weight of 50.46±0.35 g fish-1, obtained from the Fish Hatchery Center (BBI) Sawangan, Magelang, Central Java, Indonesia. The test feeds were artificial feeds supplemented with different doses of papaya leaf extract: A (0 g kg-1 feed), B (10 g kg-1 feed), C (20 g kg-1 feed), and D (30 g kg-1 feed). The research parameters included total feed intake (TFI), apparent digestibility coefficient for protein (ADCp), feed utilization efficiency (EFU), feed conversion ratio (FCR), protein efficiency ratio (PER), relative growth rate (RGR), survival rate (SR), and body nutrient composition of Java barb. The results showed that the addition of papaya leaf extract to the feed had a significant effect (p < 0.05) on TFI, ADCp, EFU, FCR, PER, and RGR, but had no significant effect (p > 0.05) on the SR and body nutrient composition of Java barb. The addition of papaya leaf extract at a dose of 30 g kg-1 feed yielded the best results for improving the growth performance and feed efficiency of Java barb at the grow-out stage.

Marine phototrophs are vertically structured across the water column and benthic habitats in response to pronounced gradients in light intensity and spectral composition. As light propagates through seawater, selective attenuation progressively modifies the underwater light field, generally favoring blue to blue-green wavelengths in clear waters, while dissolved and particulate matter can shift the available spectrum toward greener conditions. These optical gradients generate distinct spectral niches that influence the distribution and performance of cyanobacteria, phytoplankton, macroalgae, and photosynthetic corals. However, vertical organization cannot be explained by wavelength alone. Pigment composition, chromatic acclimation, photoacclimation, morphology, internal optics, and nutrient availability interact to determine the realized depth distribution of marine phototrophs. This mini-review synthesizes evidence across pelagic, coastal, benthic, and sedimentary environments to examine how spectral quality and irradiance jointly shape vertical ecological organization. Particular attention is given to complementary pigment absorption in macroalgae and cyanobacteria, chromatic acclimation in Synechococcus, photoacclimation within deep chlorophyll maxima, and whole-organism optical adaptations in deep-water corals and seaweeds. Available evidence indicates that spectral specialization is most ecologically consequential under conditions of strong light limitation, whereas nutrient–light trade-offs and morphological adaptations can substantially modify or override simple wavelength-based predictions. Vertical organization should therefore be understood as a dynamic outcome of interactions among underwater optical properties, organismal light-harvesting strategies, and resource availability rather than as a fixed sequence of pigment-defined depth zones. This framework also highlights the potential sensitivity of spectral niches to future changes in ocean optical conditions and variability.

Mangrove forests provide nature-based solutions, serving as crucial coastal defenses against natural disasters and as nurseries for marine organisms. Despite its ecological and economic importance, there is still a lack of baseline information on the species composition and diversity of Pangutaran Island's mangrove forest. It is also often marginalized, largely due to limited community understanding. The absence of localized baseline data makes it difficult to assess its biodiversity status, detect environmental degradation, or implement evidence-based policies for sustainable coastal resource management. Therefore, this study aims to determine the species composition and diversity within three selected barangays, providing the empirical foundation needed for informed conservation and policy strategies. Three 100-m transect lines were established perpendicular to the shoreline with five 10x10m quadrats. The study recorded 6 species across three families. Species diversity at the three sampling sites was low (H’ = 0.65-1.47), dominated by Rhizophoraceae. The evenness values across the three sites range from 0.3837 to 0.8671, indicating a species distribution considered semi-balanced to almost balanced. The low diversity across sites, with a dominance of small, sapling-aged trees, is likely driven by the rampant anthropogenic activity associated with resource extraction. These findings highlight the pressing need for sustainable conservation efforts. As a result, this study provides essential baseline data necessary to design effective coastal management plans aimed at protecting the ecological health of mangrove forests, specifically within the Sulu region.

Marine macroalgae play critical ecological and socioeconomic roles in coastal ecosystems, yet the global proliferation of non-indigenous macroalgal taxa poses a significant threat to marine biodiversity and habitat integrity. This mini-review synthesizes contemporary research on the most prominent invasive marine macroalgae worldwide, including Undaria pinnatifida, Sargassum muticum, Caulerpa spp., Asparagopsis spp., and the rapidly expanding Rugulopteryx okamurae. The literature reveals that while these species share highly competitive life-history traits, their invasion success and ecological impacts are highly context-dependent and density-driven. Direct consequences range from severe community simplification, shading, and spatial exclusion of native biota to subtle, localized alterations and unexpected facilitative interactions. Anthropogenic activities - predominantly shipping, aquaculture, and climate-induced warming - serve as primary vectors for primary introduction and secondary spread, complemented by localized biological vectors. Given the high economic and ecological costs associated with eradication post-establishment, management strategies are increasingly shifting toward predictive risk mapping, mechanism-based monitoring, and the preservation of native canopy integrity to mitigate disturbance-mediated invasions.

Sea cucumbers play important ecological and economic roles, making accurate species identification and genetic studies essential for their conservation and management. However, genomic DNA isolation in sea cucumbers is often challenged by the presence of ossicles and complex dermal structures. This study aimed to develop a modified method for high purity genomic DNA isolation by evaluating different tissue types and preparation techniques. A single specimen of Holothuria fuscocinerea from Karimunjawa was analyzed using anatomical and molecular approaches. Six extraction treatments were applied, including anterior tissue (P0), smooth muscle tissue (P1), dermal tissue treated with bleach (P2), homogenized muscle tissue (P3), gonad (P4), and body secretion (P5). DNA quality and concentration were assessed using Nanodrop and Quantus, followed by PCR amplification targeting the mitochondrial COI gene. Anatomical observations revealed the presence of buttons, rod, and tables ossicles, with button type being dominant. The results showed that dermal tissue treated with bleach as chemical methods for ossicle removal produced the highest DNA yield (4.76 ng μL-1 Nanodrop and 3.53 ng μL-1 Quantus) and relatively better purity compared to other tratments. PCR amplification of anterior tissue using the COIceF/ceR primer successfully generated clear DNA bands in all samples (100%), with a high identification success rate for H. fuscocinerea, indicating the suitability of the extracted DNA for molecular analysis. This study demonstrated that ossicle removal and appropriate tissue selection are critical factors in improving DNA extraction efficiency in sea cucumbers.

This study evaluated the effects of different carbon sources on the larval rearing of the mud crab (Scylla paramamosain) using biofloc technology. The experiment comprised five treatments, three replicates each with different carbon sources: (i) no carbon addition (control), (ii) granulated sugar, (iii) rice flour, (iv) wheat flour and (v) corn starch. Experimental larvae at the Zoea 1 stage were stocked in 250-L tanks at a density of 200 ind L⁻¹. Carbon sources were supplemented daily, starting from the Zoea 3 stage at a C:N ratio of 20. The results indicated that total ammonia nitrogen, nitrite, total bacterial density and Vibrio counts were significantly lower in carbon-supplemented biofloc treatments when compared to the control (p < 0.05). Conversely, larval stage index, growth in length, survival rate and crab 1 yield were significantly higher in biofloc treatments (p < 0.05). The rice flour treatment achieved the highest survival rate (9.89±0.17%) and Crab 1 yield (19,772±337 ind m⁻³), showing significant superiority over all other treatments (p < 0.05). Therefore, rice flour is recommended as the most suitable carbon source for biofloc-based mud crab larval rearing.

Marine bacteria are an interesting issue for searching of natural bioactive compounds when rising up of drug resistant bacteria and incurable diseases. This is the first report on pure bioactive compounds from a Bacillus sp. strain C-1-10 isolated from the soft coral Alcyonium digitatum in the Baltic Sea. The strain C-1-10 showed capable of yielding at least 7 natural compounds on both Glucose Yeast Malt medium and Bannett medium. The pure compounds were isolated with semi-preparative high-performance liquid chromatography (HPLC). Four purified natural substances are tested for antimicrobial activities, antifungal, cytotoxic and enzyme inhibition. All four compounds showed inhibition of Staphylococcus epidermidis and Staphylococcus aureus MRSA. The compound 5 showed rather weak inhibition of Gram-negative Escherichia coli and was inactive to phosphodiesterase 4, while the other compounds were inactive to E. coli and active against phosphodiesterase 4. However, all four pure compounds were inactive to other Gram-negative bacteria and fungi and exhibited no cytotoxic activity, and no inhibition to glycogen synthase kinase, and protein-tyrosine-phosphatase. A soft coral derived Bacillus sp. strain C-1-10 showed a promised strain for bioactive compound producing.

Fish farming is the main activity that provides food based on protein. In addition to fish having excellent nutrition for the body, fish farming can reduce fish catches from nature and at the same time maintain its population. However, in fish farming, it is sometimes constrained by water quality and diseases that can reduce quality and productivity in cultivation. To overcome this, herbs that are immunostimulants, attractants, and growth promoters can be given to increase immunity and growth. The study's results proved that fucoidan supplementation was effective in increasing North African catfish, Clarias gariepinus (Burchell, 1822) growth significantly compared to squid oil attractant supplementation for 60 days of maintenance. Meanwhile, the combination of herbal supplementation showed that ginger (Zingiber officinale) treatment 30% of the optimal dose (2.25 g) + turmeric (Curcuma longa) 70% (1.05 g) kg-1 feed, resulted in optimal C. gariepinus growth compared to other treatments. The combination of herbal feed Javanese turmeric (Curcuma xanthorrhiza) 20% of the optimal dose (10 g) + 80% garlic (Allium sativum) (24 g) produced an optimal hematocrit, while leukocrit at dose 40% Z. officinale (3.0 g) + 60% C. longa (0.9 g) was higher than other treatments in C. gariepinus. This shows that herbal supplementation from marine organisms (fucoidan) and land (garlic, turmeric, Javanese turmeric, garlic) can be used to improve the immunity and growth of farmed fish.

This study evaluated fermented cassava pulp-based wet concentrate (WCP) as a replacement for commercial pelleted feed on growth performance, feed utilization, carcass characteristics, and water quality of climbing perch, Anabas testudineus (Bloch, 1792) during an 8-week feeding trial. A total of 360 female fish (initial body weight 1.23±0.02 g) were randomly assigned to four dietary treatments with three replicates: T1 (100% commercial pelleted feed; control), T2 (67% commercial pelleted feed + 33% WCP), T3 (33% commercial pelleted feed + 67% WCP), and T4 (100% WCP). Fish fed T3 had the highest final body weight (BW) (25.63±0.43 g), weight gain (WG) (24.40±0.43 g), specific growth rate (SGR) (5.42±0.03% day-1), and average daily gain (ADG) (0.44±0.01 g day⁻¹), significantly exceeding the control for these parameters (p < 0.05). T3 also had the lowest feed conversion ratio (FCR) (1.74±0.12) and highest feed efficiency (FE) (57.47±3.66%). In contrast, T4 had the highest feed intake (0.84±0.07 g day⁻¹), highest FCR (1.98±0.18), and lowest FE (50.51±4.10%). Carcass characteristics varied among treatments, with the highest fillet yield in T2, HSI in T4, and VSI in T3. Several water-quality parameters differed significantly, but these differences were not associated with adverse effects on growth or survival. Overall, replacing 67% of commercial pelleted feed with WCP provided the most favorable combination of growth and feed utilization under the experimental conditions. WCP therefore has potential as a partial replacement for commercial feed in A. testudineus culture, although longer-term feeding, digestibility, and economic studies are needed to confirm its applicability under commercial conditions.

Macrozoobenthos are useful indicators of local habitat and environmental conditions because of their close association with benthic substrates and limited mobility. This study assessed target macrozoobenthos assemblages in the core zone of the Tanjung Palas Timur Marine Protected Area, North Kalimantan, Indonesia, using coral assemblage composition and water-quality conditions as supporting ecological context. Surveys were conducted at six observation stations from 30 July to 3 August 2025. Target macrozoobenthos were recorded using underwater visual census along one 50-m belt transect per station, covering 250 m² at each station. Coral assemblages were documented using the underwater photo transect method, while water-quality parameters were measured at station level. A total of 62 individuals from five target macrozoobenthos groups were recorded. Giant clams were the most abundant group and occurred at all stations, while sea cucumbers, sea urchins, crown-of-thorns starfish, and triton shells showed more restricted distributions. Target macrozoobenthos diversity was generally low, although Stations III and V showed comparatively higher abundance, diversity, or more balanced assemblage structure than the other stations. The related coral dataset documented 40 coral species and was used as supporting habitat context rather than as the primary focus of the study. Reef-slope stations generally showed higher live coral cover and tended to support higher target macrozoobenthos abundance or lower dominance than rubble- and sand-dominated stations. Exploratory PCA separated stations mainly along gradients of target macrozoobenthos abundance, diversity, dominance, and coral species richness. Exploratory Spearman analysis did not show statistically significant relationships and was interpreted only as station-level tendencies. Overall, this study provides an initial baseline for target macrozoobenthos monitoring in KKPTPT and highlights the need for replicate transects, seasonal surveys, direct habitat-complexity measurements, sediment assessment, and size-structure monitoring of key taxa such as giant clams.

Mangrove reforestation has been widely implemented in the Philippines, yet limited information is available on the structural and compositional attributes of natural and planted mangrove forests in Zamboanga Sibugay. This study compared the stand structure, species composition, diversity, and regeneration patterns of natural and planted in selected mangrove forests in the province using the line-quadrat plot method. Results showed that the natural mangrove forest in Siay had higher species diversity, more balanced zonal distribution, and better regeneration structure than the planted mangrove forest in Naga. In contrast, the planted forest was characterized by lower diversity, the absence of seedlings, and dominance by Rhizophora mucronata Poir, indicating a simplified community structure influenced by species selection in reforestation activities. These findings suggest that natural mangrove stands exhibit greater structural complexity and regeneration capacity than planted stands. Therefore, mangrove restoration in Zamboanga Sibugay should prioritize site-suitable native species, natural recruitment, hydrological recovery, and long-term ecological monitoring to improve restoration effectiveness.

Informal patron-client arrangements in capture fisheries can combine vessel finance, employment, social assistance, and market control, creating both protection and dependency. This study examined how boat owner-crew labor relations are reproduced and how a feasible transformation could be designed at Tenau Coastal Fishing Port and Oeba Fish Landing Base, Kupang City, Indonesia. A qualitative case study with descriptive economic support used observations, in-depth interviews, structured questionnaires, and document review from April to November 2024. The principal participants comprised 20 matched dyads, each consisting of one boat owner and one crew member; collectors, port managers, and local-government actors were supporting informants. The Theory of Planned Behavior (TPB) was used to explain why the existing arrangement persisted, while Soft Systems Methodology (SSM) translated the diagnosis into a purposeful activity system and staged intervention strategy. Owners financed vessels and operations and controlled first-sale decisions and records, whereas crew members supplied labor but did not determine buyers, prices, or post-landing revenue allocation. The arrangement persisted because crew work provided income and social support under limited alternatives, while owners sought to protect capital, manage risk, secure labor, and coordinate marketing. Norms of loyalty, gratitude, kinship, and informality reinforced these constraints. The analysis produced one multi-actor root definition and eight minimum activities for shifting opaque and dependency-based relations toward more transparent, clearly defined, and balanced arrangements. The strategy begins with shared information, followed by minimum work agreements and mediation, crew economic capability, and alternative economic access. Social-norm change, behavioral constraints, and system redesign must therefore be addressed together without disregarding the legitimate financing and risk-bearing role of boat owners. Methodologically, the sequential integration of TPB and SSM links behavioral explanation to conceptual system redesign.

Fusarium wilt and other soil-borne vascular diseases remain major constraints to sustainable crop production because their causal agents persist in soil, interact intimately with host roots, and are difficult to eradicate using conventional management practices. Increasing concerns regarding pesticide residues, environmental contamination, pathogen resistance, and deterioration of soil biological health have stimulated interest in rhizosphere-based biological control. Rhizospheric fungi, particularly Trichoderma, Clonostachys, arbuscular mycorrhizal fungi, selected Penicillium spp., and non-pathogenic Fusarium isolates, can suppress soil-borne pathogens through complementary mechanisms including mycoparasitism, competition, antibiosis, hydrolytic enzymes, volatile organic compounds, nutrient mobilization, root colonization, induced systemic resistance, hormonal modulation, and restructuring of the soil microbiome. Recent research indicates that disease suppression should increasingly be viewed as an emergent property of the plant–pathogen–microbiome–environment continuum rather than as the consequence of direct antagonism by a single microorganism. Disease-suppressive soils, microbiome engineering, synthetic microbial communities, multi-omics, precision formulation, and controlled delivery are consequently emerging as important directions for next-generation biocontrol. Recent studies further demonstrate that root exudates and agricultural practices can reshape rhizosphere communities associated with Fusarium suppression, while advances in formulation technology are improving the stability and applicability of fungal inoculants. Beyond terrestrial agriculture, fungal biotechnology offers an emerging connection with agro-aquaculture through nutrient recycling, agricultural-residue valorization, wastewater treatment, fungal–microalgal systems, and circular bioeconomy approaches. However, direct introduction of terrestrial fungal biocontrol agents into aquatic production systems remains premature and requires independent ecological, toxicological, and regulatory assessment. This review critically synthesizes the ecology, mechanisms, biotechnology, formulation, field constraints, climate-resilience potential, and agro-aquaculture prospects of rhizospheric fungi, and proposes a systems-level framework for their integration into sustainable disease management.

Coastal dikes address coastal erosion and tidal flooding in vulnerable areas. However, their effectiveness depends not only on technical performance but also on how coastal communities understand and respond to their development. This study examined the socioeconomic characteristics, knowledge, perceptions, and aspirations of fishing communities regarding a planned coastal dike in Wedung Subdistrict, Demak Regency, Indonesia, and assessed the relationship between knowledge and perception. A descriptive quantitative approach was applied to 64 fishermen selected through snowball sampling. Data were collected through questionnaires, interviews, field observations, and document reviews and analyzed using descriptive statistics and the Chi-square test. Most respondents (81.12%) had low knowledge of the planned coastal dike, while 60.16% had negative perceptions. Respondents recognized its potential to reduce coastal erosion and tidal flooding and protect coastal settlements, but 51.56% were concerned about access to fishing grounds, navigation routes, and livelihood sustainability. The Chi-square test showed a significant relationship between knowledge and perception (p < 0.05), indicating that greater knowledge was associated with more positive perceptions. The findings suggest that coastal dike planning should involve clear, continuous communication with fishing communities and address their concerns about fishing access and livelihoods. Incorporating local knowledge and community aspirations may improve acceptance of coastal protection measures and help ensure that they address both coastal risks and community needs.

This study aimed to characterize changes in surface morphology of the marine microalga Dunaliella salina following lead acetate exposure using Scanning Electron Microscopy (SEM) and to determine its elemental composition using Energy Dispersive Spectroscopy (EDS). The work is intended to improve understanding of D. salina responses to lead contamination and to support environmental monitoring and management of heavy-metal pollution. The D. salina culture was obtained from a laboratory stock maintained at the Laboratory of Molecular Biology and Marine Pharmaceutics, FPIK UNSRAT. Cells were motile and displayed morphological variability, ranging from elliptical to cylindrical forms, with radially symmetric cells measuring approximately 2.8-40 µm. Seawater for the culture medium was collected from an unpolluted coastal area, filtered through a 0.45 µm membrane using an aspirator and diluted with distilled water to a salinity of 20 ppt. Cultivation was conducted in Walne medium at 25°C and 20 ppt under continuous illumination from a 20 Watt fluorescent lamp. Cultures were harvested during the exponential growth phase, which was monitored daily by hemocytometer counts under a light microscope and then exposed to lead acetate at 30, 50 and 80 ppm respectively. Harvested biomass was centrifuged prior to SEM analysis, while cell density was quantified microscopically using a hemocytometer. The results showed no significant differences in cell density among the tested lead acetate concentrations and cell density was not associated with the observed structural characteristics across treatments. However, SEM observations demonstrated that lead acetate exposure caused evident cell-wall damage and measurable alterations in the surface morphology of D. salina. The mineral content found in D. salina consisted of carbon (C), oxygen (O), sodium (Na), magnesium (Mg), silicon (Si), sulfur (S), chlorine (Cl), potassium (K) and lead (Pb).

The accordion‑shaped shrimp trap, locally called Bubu Naga, is increasingly used by fishermen in Tambak Lorok to catch white shrimp (Penaeus  merguiensis). Although the trap yields high catches, its effect on marine resources and the environment must be examined. This study evaluated the environmental friendliness of Bubu Naga using nine criteria from the FAO Code of Conduct for Responsible Fisheries (CCRF). Data were collected during six fishing trips in November 2024 and analyzed with descriptive statistics. The total catch was 32.04 kg, of which 13.43 kg (42 %) were target shrimp and 18.61 kg (58 %) were bycatch. Because the by‑catch proportion exceeded that of the target species, the gear does not meet the CCRF requirement for high selectivity. However, when all nine criteria were scored, Bubu Naga obtained a total score of 32 out of 36, placing it in the “very environmentally friendly” category. In summary, while the catch composition suggests limited environmental friendliness, the overall assessment indicates that Bubu Naga is highly acceptable from an ecological perspective. Managers should focus on improving species selectivity of the trap, so that its overall environmental performance can be fully realized.

The population of striped snakehead, Channa striata (Bloch, 1793), in nature is greatly declining, so efforts are needed for domestication. The reproductive biology of fish plays a significant role in fish domestication. The purpose of this study was to determine the morphology of the gonadosomatic index (GSI) and gonado maturity level (GML) of snakehead fish in three types of swamp waters. Data were analyzed using descriptive methods and one-way ANOVA followed by Tukey's Honestly Significant Difference (HSD) post hoc test to determine significant differences across maturity stages and habitats. The study was conducted from May to September 2025. The fishing locations were in swamp waters in Danau Bangkau, Tanah Laut, and Batola, South Kalimantan. Fifty fish samples were taken, with almost the same weight and length, every 15 days at five stations. The study found peak GSI in monotonous swamps (5.07±0.07%) in September, indicating optimal spawning conditions. Maximum GSI values and peak period. The identification of monotonous swamps as the habitat supporting the highest reproductive investment and September as the peak spawning period offers clear guidance for broodstock sourcing and breeding schedules. Selecting broodstock during peak maturity and from habitats with naturally elevated GSI values may enhance spawning success, egg quality, and seed production efficiency in hatchery systems. These findings support habitat-informed broodstock management and reproductive synchronization strategies, thereby strengthening the scientific basis for sustainable domestication and large-scale aquaculture development of snakehead fish.

Shrimp aquaculture is a major economic activity in Tamil Nadu, with the Nagapattinam and Mayiladuthurai districts together accounting for nearly 45% of the state’s licensed shrimp farms. Although the sector has periodically attracted concern regarding its environmental sustainability particularly with respect to shrimp farm discharge water quality and coastal ecosystem health there remains a paucity of empirical, field-based assessments from this region. The present study evaluated key environmental parameters across twelve shrimp farms and two control sites located in Nagapattinam and Mayiladuthurai districts. Water quality and plankton composition were assessed during the summer and pre-monsoon seasons, with samples collected from intake waters, farm discharge points, discharge-receiving areas, and control sites. Physico-chemical parameters including ammonia, nitrite, nitrate, and chemical oxygen demand (COD) were analysed and compared against regulatory standards prescribed by the Coastal Aquaculture Authority (CAA) and the Tamil Nadu Pollution Control Board (TNPCB). Statistical analyses were conducted using one-way ANOVA and independent t-tests to examine spatial and seasonal variations in water quality (p < 0.05). Results indicated no significant differences in most parameters among the different water types, with only localized increases in COD (p < 0.001) observed values that nonetheless remained well within permissible limits. Plankton analysis revealed diatom dominance and diverse zooplankton assemblages, suggesting ecological stability in the receiving environments. Overall, the findings demonstrate that shrimp farming practices in the study areas are environmentally compliant and exert minimal ecological impact, thereby reinforcing the sector’s sustainability and its continued importance as a source of rural livelihood and economic growth in coastal Tamil Nadu.

Slaughterhouses generate large volumes of wastewater that is rich in organic matter, nutrients, heavy metals, and microbial contaminants. In Rabat, as in many other cities, managing slaughterhouse wastewater is a significant environmental challenge. Direct discharge of untreated wastewater can contaminate soil, surface water, and groundwater, thereby threatening environmental quality and public health. This study evaluated soil quality by examining the accumulation and bioaccumulation of heavy metals, including chromium (Cr), lead (Pb), copper (Cu), zinc (Zn), cadmium (Cd), and iron (Fe), and their transfer from soil to bean plants (Vicia faba). Metal concentrations were determined in agricultural soils and different plant organs (roots, stems, and leaves) exposed to irrigation with untreated wastewater. The results showed that heavy metals mainly accumulated in the soil and roots, with lower concentrations detected in stems and leaves. Elevated concentrations of Pb and Zn were observed in the roots, indicating limited translocation of these metals to the plant's aerial parts. Additionally, soils irrigated with untreated wastewater exhibited higher metal concentrations, contributing to increased metal uptake by V. faba. These findings demonstrate that using untreated slaughterhouse wastewater for irrigation promotes the accumulation of heavy metals in soil and their transfer to crops. This highlights the importance of implementing effective wastewater treatment and regular monitoring programmes to prevent the contamination of agricultural products by heavy metals and to protect environmental and food safety.

This study aimed to analyze the effect of adding shallot (Allium cepa) liquid into fish feed on the growth performance and profitability of farmed red tilapia (Oreochromis sp). Three different doses of 0.0% (treatment A), 2.5% (treatment B), and 5.0% (treatment C) of feed weight were used in this completely randomized design study done within 30 days. Test fish with an initial size of 2.11±0.03 g were reared in fiberglass tanks at a stocking density of 30 fish per tank and fed 4% of biomass per day. The parameters observed included specific growth rate (SGR), weight gain rate (WGR), survival rate (SR), feed conversion ratio (FCR), and benefit cost ratio (BCR). The results showed that shallot liquid addition to the fish feed significantly affected the growth, feed efficiency, and BCR. Liquid shallot at low doses produced high WGR and SGR values along with a more efficient FCR. In this study, the control treatment (treatment A, 0.0% shallot liquid) resulted in the most optimal performance, while the highest SR and BCR values were obtained in the control treatment. Polynomial regression optimization analysis indicated that the optimal dose ranges low, between 0.131 and 0.694%.

The biochemical composition of the seagrass Halodule pinifolia collected from Pasiagan, Bongao, Tawi-Tawi, Philippines was investigated to assess its potential nutraceutical and pharmacological applications. Phytochemical screening revealed the presence of alkaloids, tannins, flavonoids, phenolics, saponins, steroids, and triterpenoids. Proximate analysis demonstrated considerable nutritional value, with protein (12.46%), carbohydrates (52.82%), lipids (0.85%), and ash (33.87%), with the high ash content suggesting substantial mineral content. Cytotoxicity assessment yielded an LC₅₀ of 867.32±0.028 µg mL-1 (mean±SD), indicating low cytotoxicity. Quantitative analyses showed a total phenolic content (TPC) of 0.869±0. 014 mg GAE g-1 and a total flavonoid content (TFC) of 0.34±0.091 mg QE g-1. Antioxidant assays demonstrated free-radical-scavenging activity in both DPPH (0.725±0.021 mg Trolox g-1) and ABTS (0.196±0.017 mg Trolox g-1) systems. These findings indicate that H. pinifolia contains nutritionally relevant constituents and phytochemicals associated with antioxidant activity. The species, therefore, warrants further investigation as an underexplored marine resource for potential functional food and nutraceutical applications.

In Indonesia, the domestic sea salt industry faces major challenges for supply and demand. Therefore, this study seeks to develop a partnership business model aimed at fostering sustainability in the Indonesian sea salt industry. Utilizing an exploratory descriptive methodology with a qualitative focus, this study incorporates the business model canvas, sustainability aspect, partnership canvas, and value innovation framework. The participants comprised 113 sea salt farmers and seven sea salt processing micro, small, and medium enterprises (MSMEs) from Java and Madura Islands. The data were analyzed using deductive content analysis. Triangulation and kappa statistical tests were performed to assess the validity and reliability. The kappa coefficient obtained was 0.83, which is an excellent agreement, surpassing the threshold of 0.75. Sea salt processing MSMEs aim to expand their market share by facilitating farmer access and providing collaborative training on jointly developed sea salt-processing methods. Conversely, smallholder sea salt farmers aim to enhance their income by participating in co-designed training programs, collaborative production and marketing initiatives, and contractual agreements for sea salt production.

Mediterranean marine protected areas require repeatable fish monitoring to evaluate conservation and fisheries outcomes, yet many management programmes begin with sparse, heterogeneous observations. This study evaluates a pilot underwater visual census undertaken on 19 August 2026 in Al Hoceima National Park, Morocco, places it within surveys conducted in 2002 and 2019, and uses the combined evidence to design an operational sentinel-monitoring framework. Two contrasting coastal units - one recorded as natural habitat and one as an artificial breakwater - were surveyed in 2026. Fish counts were consolidated by taxon and field size class, taxonomic names were quality-controlled, and assemblages were described using abundance, richness, Shannon diversity, Pielou evenness, Simpson dominance and Bray-Curtis dissimilarity. The 2002 MedMPA survey recorded 72 species across multiple sites and depth bands, whereas 22 visual surveys in 2019 recorded 3,577 individuals and 16 families; reported richness varies between 42 and 44 species within the source report. Those historical datasets identify recurrent sparid and labrid components and high proportions of small fish at some shallow locations, but their different coverage and effort preclude a direct numerical trend with 2026. Because the 2026 transect geometry, depth and spatial replication were not documented, analyses were intentionally restricted to raw-count descriptions and no habitat effect was tested. The pilot recorded 290 individuals representing nine taxonomic units. The natural unit contained 199 individuals and seven taxa, whereas the breakwater contained 91 individuals and five taxa. Four schooling or abundant groups - Boops boops, Sarpa salpa, Oblada melanurus and Mugil sp. - accounted for 90.0% of all records. Bray-Curtis dissimilarity was 0.745, indicating a marked descriptive contrast that cannot be attributed causally to habitat. The pilot supplies a traceable summer baseline, while the historical surveys guide station placement and ecological questions. Fixed georeferenced transects, replicated habitat units, standardized effort, environmental covariates, photographic validation and seasonally homologous sampling are required before interannual change can be estimated.

The use of agro-industrial by-products as functional feed additives represents a promising strategy to enhance sustainability and digestive efficiency in aquaculture. This study investigated the dose-dependent effects of bromelain derived from pineapple processing waste on digestive physiology, nutrient utilization, and economic performance in snakeskin gourami, Trichopodus pectoralis Regan, 1910. Fish (95-98 g) were fed diets supplemented with 0, 4, 8, or 12% bromelain for 90 days in a completely randomized design. Growth performance, survival, and feed utilization were not significantly affected by dietary treatments (p > 0.05), suggesting that exogenous protease supplementation did not enhance growth under nutritionally adequate conditions. However, bromelain inclusion elicited a pronounced, dose-dependent modulation of digestive enzyme activity. The 8% supplementation significantly enhanced pancreatic protease and amylase activities. This indicates improved digestive capacity and better nutrient assimilation. In contrast, the 12% inclusion level was associated with reduced activity of specific enzymes, suggesting feedback inhibition or enzymatic imbalance at excessive doses. Despite the absence of significant growth responses, a progressive increase in benefit-cost ratio was observed with increasing bromelain inclusion, reflecting improved production efficiency. Variations in muscle composition were primarily attributed to moisture-associated dilution effects rather than reduced protein deposition. Collectively, these findings demonstrate that bromelain derived from pineapple waste functions as a physiologically active feed additive that modulates digestive processes in a dose-dependent manner, with 8% identified as the optimal inclusion level. This study provides mechanistic evidence supporting the valorization of agro-industrial waste as a functional input in sustainable aquaculture systems.

Banggai cardinalfish (Pterapogon kauderni) is an endangered, range-restricted apogonid endemic to the Banggai Archipelago (Banggai Islands), Indonesia, and a flagship species of the marine ornamental fish trade. Aquarium-mediated releases have established non-native populations, including in Lembeh Strait, North Sulawesi. This study compared population density, size structure, and microhabitat use of P. kauderni between introduced and native ranges using underwater visual census along 50-m x 5-m belt transects in Lembeh Strait (March 2021) and in the Banggai Islands (October 2021). Individuals were counted, assigned to three size classes (recruit, 1.8 cm, SL; juvenile, 1.8-3.5 cm, SL; adult, > 3.5 cm, SL), and recorded with associated protective microhabitats: branching coral, Diadema sea urchins, sea anemones, and seagrass. A total of 3,997 individuals from 45 colonies were recorded (42 with recorded microhabitat). Mean density was 2.00±0.62 ind m-2, with no significant difference between introduced and native ranges (Mann–Whitney U = 10.0, p = 0.69). Populations were adult-dominated overall (73.7%), while pooled descriptive proportions showed more juveniles in Lembeh and more adults in Banggai; however, station-level comparisons detected no significant regional differences. Coral and Diadema were the most frequent colony microhabitats, and 88.2% of individuals were associated with Diadema. Colonies with Diadema contained significantly more individuals (p = 0.005), and abundance increased with the number of protective microhabitats present (Spearman ρ = 0.34, p = 0.028). An exploratory colony-level comparison showed higher median abundance in colonies with Diadema rather than in colonies with none, but this result was interpreted cautiously because multiple colonies occured within the same stations. These findings provide evidence for habitat-based monitoring and management of native and introduced populations in Indonesian waters.

Kappaphycus alvarezii and Eucheuma denticulatum are important seaweed species cultivated in Karimunjawa National Park, Indonesia, yet their economic viability within a protected area remains understudied. This study evaluated the profitability of seaweed cultivation using production costs, market access, value chain conditions, and three financial indicators: benefit-cost (B/C) ratio, return on investment (ROI), and net present value (NPV). Primary data were collected through questionnaires from 50 cultivators in Mrican, Telaga, and Batulawang beaches. All cultivators recorded positive ROI and NPV values and B/C ratios above 1.0, while 96% achieved a B/C ratio ≥ 2.0. The mean B/C ratio, ROI, and NPV were 6.105, 2,459.96%, and Rp 136,028,118, respectively. These results demonstrate that seaweed cultivation is economically viable and provides an important livelihood for coastal communities in Karimunjawa National Park. However, dependence on a single market, limited bargaining power, price fluctuations, and seasonal production variability remain key constraints. Strengthening market access and production management could further improve the economic resilience of seaweed cultivation while supporting conservation objectives.

Biofloc technology is a sustainable aquaculture strategy that enhances nutrient recycling and water quality. However, optimizing the carbon-to-nitrogen (C/N) ratio is essential for maximizing production efficiency. This study evaluated the effects of four C/N ratios (10:1, 15:1, 20:1, and 25:1) on growth performance, feed utilization, carcass traits, whole-body proximate composition, water quality, biofloc characteristics, and economic efficiency of sex-reversed climbing perch (Anabas testudineus) cultured in biofloc systems. Fish were reared for 8 weeks in a completely randomized design with 4 treatments and 3 replicates per treatment. The C/N ratio significantly affected growth performance, feed utilization, carcass traits, biofloc characteristics, several water quality parameters, and production cost (p<0.05). Fish cultured at C/N 20:1 achieved the highest final weight (15.94±0.77 g) and the lowest feed conversion ratio (1.82±0.02), together with favorable water quality and the lowest total feed and carbon cost (1.41±0.04 USD kg-1 of weight gain). Although C/N 25:1 produced the highest floc volume and total suspended solids, C/N 20:1 resulted in the most favorable overall growth and feed utilization performance among the tested treatments. Overall, among the tested C/N ratios, 20:1 provided the most favorable balance between microbial activity, nutrient utilization, water quality, fish performance, and economic efficiency, supporting sustainable biofloc-based culture of sex-reversed climbing perch.

The development of the feed industry in sustainable aquaculture activities largely relies on plant-based proteins, which are widely available and relatively inexpensive, to address the global fishmeal shortage. However, these plant-derived protein sources contain various anti-nutritional factors, such as non-starch polysaccharides, phytates, protease inhibitors, tannins, and saponins, which are less utilizable by fish, thereby limiting nutrient utilization and disrupting mineral bioavailability in aquatic species. Phytate in feed forms complexes by binding to proteins and minerals in the digestive tract of animals. These phytate-protein complexes cause problems in protein digestibility, leading to decreased digestibility, protein utilization, and growth. In addition, phytate cannot be digested by proteolytic enzymes, and the activities of enzymes such as pepsin, amylopsin, and amylase are inhibited by phytate. Feed supplementation with phytase hydrolyzes phytate, thereby releasing phosphorus from the phytate complex. As a result, phosphorus becomes freely available in the feed, playing an important role in improving the overall performance of fish and increasing the bioavailability of minerals to fish, thereby making it cost-effective and environmentally friendly. Phytase in feed promotes increased fish growth rates due to improved protein digestibility and nutrient absorption as a result of optimal function in the pyloric ceca of the intestine. The addition of phytase to feed can enhance the conversion of trypsinogen to trypsin, which breaks down proteins into amino acids, thereby increasing digestive enzyme activity and improving the digestibility of proteins and amino acids in feed that uses plant-based ingredients as protein sources.

Squid (Loligo sp.) is an economically important fishery resource in the Karimunjawa Islands, Central Java, Indonesia, yet information on its length-weight relationship and population dynamics were limited. This study analyzed the length-frequency distribution, length-weight relationship, growth, mortality, and exploitation rate of squid catch in Karimunjawa Island. A total of 431 squid individuals were sampled from fish-trading sites over seven days each month from December 2024 to January 2025. Mantle length and body weight were measured, and growth parameters were estimated using the ELEFAN I method in FiSAT II based on the von Bertalanffy growth model. Mantle length ranged from 22.9 to 48.3 cm, with the 25.1-28.0 cm size class accounting for 35% of the sample. The length-weight relationship was W = 1.38L^1.6937 (R² = 0.6041), with a growth coefficient (b) of 1.6937, indicating negative allometric growth. The estimated asymptotic length (L∞) was 49.8 cm, with a growth coefficient (K) of 0.58 year⁻¹. Natural mortality (M), total mortality (Z), and fishing mortality (F) were 1.12, 1.17, and 0.05 year⁻¹, respectively, resulting in a low exploitation rate (E) of 0.04, well below the optimum level of 0.5. These findings indicate that the squid resource in Karimunjawa waters was not overexploited during the study period. Continued monitoring and precautionary management, including control of fishing effort and minimum catch-size regulations, are recommended to support sustainable utilisation.

Blood cockle (Anadara granosa) farming has become one of the most economically important coastal aquaculture activities on the east coast of Sumatra, Indonesia. Despite its significant contribution to local livelihoods, exports, and regional economic growth, the rapid expansion of the industry has generated increasing concerns regarding coastal governance, legal certainty, and market concentration. This study was aimed to analyze the legal and monopoly issues associated with blood cockle farming and their implications for sustainable coastal resource management. A qualitative case study approach was employed using field observations, stakeholder interviews, document analysis, and review of relevant legislation governing coastal areas, fisheries, and marine spatial planning. The findings reveal that blood cockle cultivation is predominantly conducted on state-owned intertidal mudflats where formal tenure rights are generally absent. Ownership claims are largely based on customary occupation and informal local agreements, resulting in frequent disputes over cultivation boundaries, unauthorized harvesting, and restricted public access to coastal resources. The study further identifies overlapping institutional authority and inconsistent regulatory implementation as major obstacles to effective governance. Market analysis indicates increasing concentration of productive farming areas, capital ownership, and export marketing networks in the hands of a limited number of investors and collectors. This condition creates localized monopoly over cultivation grounds and oligopsonistic market structures that weaken the bargaining power of small-scale farmers and increase their dependence on dominant buyers. Consequently, economic benefits are distributed unevenly, while access to productive coastal resources becomes increasingly restricted for traditional fishing communities. The study concludes that sustainable development of blood cockle farming requires integrated coastal governance based on transparent tenure allocation, strengthened legal enforcement, equitable market institutions, and participatory resource management. Such institutional reforms are essential to balance economic development with social equity, environmental sustainability, and long-term resilience of Indonesia's coastal aquaculture sector.

Processing of catfish (Clarias spp.) produces substantial quantities of bone waste rich in calcium and phosphorus, which is typically discarded or relegated to low-value feed. The present study evaluated catfish bone powder (CBP) as a mineral fortificant in fish meatballs (“bakso ikan”) by assessing nutritional, sensory, physicochemical, microbiological, and economic qualities. Five formulations (0, 5, 10, 15, and 20% CBP, substituting catfish meat) were prepared using a completely randomised design (CRD) with five replicates and analysed for proximate composition, calcium and phosphorus content, pH, water-holding capacity (WHC), lipid oxidation, texture, and 9-point hedonic acceptability over 24 hours of ambient storage (28±1°C). Microbiological safety of the CBP and the fortified product was confirmed through total plate count (TPC), total coliform, Escherichia coli, and Salmonella spp. analyses. CBP inclusion increased ash, calcium, and phosphorus content in a dose-dependent manner (p < 0.01), and all formulations complied with the Indonesian National Standard (SNI 7266:2017) for ready-to-eat fish meatballs. The 10% CBP formulation achieved the highest overall sensory acceptability (p < 0.05) and the best firmness and moisture retention, whereas pH declined progressively during storage across all treatments, most slowly in the control and most rapidly at 20% CBP, and lipid oxidation, WHC, and texture all changed in a dose- and time-dependent manner. Economic analysis indicated a reduction in raw-material cost and an increase in projected profit margin for the 10% CBP formulation relative to the control under a modelled market scenario. A 10% CBP inclusion level is recommended as a nutritionally enriched, microbiologically safe, sensory-acceptable, and cost-effective strategy that valorises aquaculture by-products in accordance with circular-economy principles.