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.