Evaluating the potential of aquaculture in the Hoa Binh reservoir with carrying capacity and water quality indices

Not only does the Hoa Binh reservoir play essential roles in water storage for electricity generation and flood regulation, but also it has great potential to aid aquaculture production. Presently, aquaculture production sits at around 9,200 tons/year; however, a recent MARD circular (#16 in 2015) estimated that maximum production would approach 10,000 tons/year in the productive photic zone. This paper supports increased capacity towards a sustainable commodity production model by optimizing production levels and farming practices. To reach this goal, it is necessary to determine water quality parameters using the Relative Water Quality Index (ReWQI) and carrying capacity (CC) analysis. Data was obtained from 30 sites at upstream, midstream, and downstream sections of the reservoir during the 2019 dry and wet seasons. The results from the ReWQI reflected good water quality potential (rated between 92-100) for aquaculture. The total nitrogen (TN) and total phosphorus (TP) levels of 10,794.9 kg/day and 1,965.4 kg/day, respectively, indicate high biological productivity resulting in strong fish growth potential. CC analysis and overall water quality reflect the potential for sustainable and increased productivity to 22,730.4 tons/year, which is an increase in production of over 13,200 tons/year compared to the current period. To reach a higher yield of 40 kg/year/m3 within each cage (5,040 kg/cage/year), the corresponding increase in number needs to be 4,510 cages based on a common cage size of 126 m3 (6x6x3.5 m). In order to reach these future production goals, this work concludes that the local government should begin spatial planning decisions based on appropriate cage allocation and distribution with respect for regular monitoring of water quality and nutrient load capacity of the environment to reach sustainable aquaculture development.

Effects of active and passive enrichment regimes on fecal glucocorticoid metabolite levels in captive Indian leopards (Panthera pardus fusca)

Environmental enrichment improves health and wellbeing of zoo animals. To test this hypothesis, we used Indian leopards, one of the popular zoo animals, as a model system to understand effects of active (interacting) and passive (noninteracting) enrichment elements on stress hormone levels of captive individuals. We included three enrichment categories, category ‘A’ (having both active: large size cage, and passive: controlled temperature, playback of forest sounds and sound proof glasses to filter visitors’ noise, enrichment elements), category ‘B’ (active enrichment type I, small size cage with air coolers), and category C (active enrichment type II, medium size cage without air coolers) for the leopards (n=14) housed in two Indian zoos. We standardized a non-invasive method to measure fecal glucocorticoid metabolite (fGCM) levels in captive leopards. The standardized fGCM assay was further validated by analysing samples from free-ranging leopards, as well. The fGCM levels (Mean±SE) were 10.45±2.01 and 0.95±0.003μg/g dry wt of feces in captive and free-ranging leopards, respectively. Our results demonstrated that fGCM levels of leopards in categories B and C were significantly (P<0.05) different from each other, thus, indicating cage size (an active enrichment element) as an important factor in influencing the physiology of the sampled animals. Overall, the findings of the study will contribute towards informing policies for management of the Indian leopards.

PERTUMBUHAN BURUNG PUYUH (COTURNIX COTURNIX JAPONICA) UMUR 3 MINGGU DENGAN PERBEDAAN KEPADATAN DI DALAM KANDANG

The purpose of this study was to determine the growth of quail aged 3 weeks, based on different cage densities. Completely randomized design was used during the study, with the density of quails in cages were 11 (P1), 13 (P2), 16 (P3), and 20 (P4). The results showed that differences in quail density in cages affected (P0.05) body weight, consumption, and conversion of quail during rearing. the number of quail in the cage is 11 for a cage size of 35x30x40 cm. Body weight, consumption, and conversion of feed produced at 3 weeks of age were: 95.52 gr, 12.53 gr, 0.13

Egg production parameters of quails receiving dietary betaine supplementation with different floor space in a tropical environment

This study investigated the effect of dietary betaine supplementation and floor space on quail egg production parameters. With six replicates, four hundred fifty-six quails (21-day-old) were randomly assigned to a 2×2 factorial arrangement. The first factor was floor space of 225 cm2 (F1) and 164 cm2 (F2) by allocating 16 and 22 birds per cage (size: 3600 cm2). The second factor was dietary betaine supplementation at 0% (CON) and 0.15% (BET). Egg production was collected in 2 periods (2×28 days) starting from 43 days old. The age of the first production, 10%, 50%, and peak production, was also recorded. There is an interaction between dietary betaine supplementation and floor space on the age of productive parameters, where quails receiving betaine supplementation reached faster 50% production and peak production (p<0.05). Furthermore, the F1 group had a higher average egg production than F2 (p<0.05). BET group had a higher average egg production than CON (p<0.05). Thus, floor space 225 cm2 can be applied in the tropics provided the quails received dietary betaine supplementation.

Acclimatization of transformed seaweed Kappaphycus alvarezii carrying lysozyme gene in culture flask and the cultivation in floating net cage in Pangkep coastal

The in vitro transformation of the lysozyme gene in seaweed K. alvarezii has been successfully executed to increase the viability against ice-ice disease. There were two major stages in this research; (1) transformation of lysozyme gene in seaweed K. alvarezii which was carried out on laboratory scale and the cultivation of gene-transformed explants in the culture flask stored in “culture chamber”; (2) the acclimatization in floating net cages of green nets (mesh size of 1 mm) with cage size of 50 x 50 x 50 cm, the population density of 200 explants and cultivated for two weeks. The explants were then transferred to blue nets (mesh size of 2 mm) with a cage size of 50 x 50 x 50 cm for four weeks of rearing. The plants were then enlarged using a long-line method in the floating net cage, by tying the seaweed using a double line with a gap of 15 cm each. The measurement of weight, bud lengths, and water quality was carried out within 2 weeks. The result shows that the daily growth rate of the transformed seaweed during the regeneration stage in the culture flask was around 0.33-0.4%/day, meanwhile during the acclimatization stage in the green nets the was 0.65-1.6%/day, and even more, increased during the acclimatization stage in the blue nets with DGR of 2.28-2.3%/day. During the enlargement stage in the floating net cages, the lysozyme-transformed seaweed showed an even higher DGR with a value of 3.2-8.2%/day. The results of the integration of the lysozyme gene in seaweed were indicated by the presence of a 670 bp of amplification products, that is the same total length of the 35 S-F promoter fragments and Nos T-R in the expression vector. Based on these results, the lysozyme gene was successfully transformed in K. alvarezii seaweed.

The use of artificial feed in Haliotis squamata farming in submerged cage culture system at Lae-Lae island, Makassar

This study investigated the use of a combined formula of artificial feed and fresh marine algae Gracilaria sp in a submerged cage culture system and its effect on Haliotis squamata relative growth and survival rates. The experiment was performed in Lae-Lae Island, Makassar from May to October 2016. The sample Abalone juvenile larvae were 1.5 cm in size and stocked at a density of 30 pcs/cage. The cage size was 30 cm x 15 cm x 7 cm and equipped with a 2-inch Paralone pipe. This experiment employed a completely random design (CRD) with 3 treatments and 3 replicates. The applied treatment included the combination of artificial feed and fresh marine algae Gracilaria sp. Each treatment included: A. 25% artificial feed + 75% fresh marine algae, B. 50% artificial feed + 50% fresh marine algae, C. 75% artificial feed + 25% fresh marine algae, and was given at the proportion of 20% of the abalone's weight. The results of the study indicated that the use of a combined artificial feed with fresh marine algae (Gracilaria sp.) had no significant effect on relative growth and survival rates of Haliotis squamata. Although feed treatment did not significantly affect the relative growth and survival rate, descriptively, treatment A contributed to the most optimal relative growth and the survival rate compared to treatments B and C.

Adsorptive Removal of Cesium Ions Using Prussian Blue Immobilized Coffee Ground Biochar

Objectives: Among various radioactive contaminants, radioactive cesium is one of the most harmful radionuclides that causes human health issues due to its high emission of gamma-ray, high solubility, high mobility, high fission yield, and long half-life. Different kinds of adsorbents have been developed for the removal of cesium from radioactive wastewater. Especially, biochar has attracted great attention as a potential adsorbent in the treatment of pollutants and for water purification. In addition, Prussian blue is a cubic lattice structure that contains a cage size similar to the hydrated cesium ionic radius, indicating it can selectively remove cesium ions. Therefore, the aim of this study is to investigate the cesium adsorption performance of synthesized Prussian blue-immobilized coffee ground biochar (PB-CGBC) under various experimental conditions for cesium removal from radioactive wastewater.Methods: After wasted coffee ground was washed and dried, it was heated at 400℃ with 10℃/min of heating rate and 5 h of retention time in a furnace with little or no available air. The PB-CGBC was synthesized using a facile co-precipitation method. Fourier transform-infrared spectroscopy, X-ray diffractometer, field emission-transmission electron microscope, Brunauer-Emmett-Teller, and zeta potential analyzer were used to analyze physico-chemical characteristics and surface structure of the synthesized adsorbents. The kinetic and equilibrium experiments of cesium adsorption on PB-CGBC were carried out and the effect of pH, temperature, initial cesium concentration, and contact time were also investigated in a batch system.Results and Discussion: The characteristic analysis clearly confirmed the successful synthesis of PB-CGBC, indicating its abundant functional groups and special surface structure. In the batch study, it was found that the cesium adsorption onto the PB-CGBC was exothermic nature. The Elovich kinetic model and Temkin isotherm also provided a good correlation with the cesium adsorption reaction onto the PB-CGBC. The maximum adsorption capacity of PB-CGBC for cesium was 129.57 mg/g at 15℃ and pH 8 at 40 mM of an initial cesium concentration, which was one of the highest values among those of previously reported adsorbents.Conclusions: In this study, the PB-CGBC was synthesized by immobilizing Prussian blue to the surface of coffee ground biochar and successfully applied for the adsorptive removal of cesium ions. Based on the experimental results, the synthesized PB-CGBC can be served as a great adsorbent for treatment of wastewater polluted with radioactive cesium.