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This review paper provides a comprehensive overview of recent advancements in energy storage applications, focusing on the utilization of fish industry waste as a sustainable resource. The paper is structured into several key sections, each highlighting a different aspect of this emerging field. Firstly, it explores the use of nanoporous carbons for high-density lithium-ion battery (LIB) anodes, discussing their potential to enhance energy storage capabilities. Secondly, it examines the development of advanced LIB anodes from fish waste-derived nanostructures, showcasing novel approaches to material synthesis. Additionally, the paper delves into the utilization of biomass-derived carbons for sodium-ion battery (NIB) anodes, presenting insights into their role in advancing energy storage technology. Furthermore, it discusses the integration of biomass-derived porous carbons to improve the performance of lithium-sulfur batteries, highlighting strategies to overcome existing limitations. Moreover, the paper explores the application of biomass-derived carbon materials in supercapacitors, emphasizing their potential for high-performance energy storage solutions. Lastly, a significant focus is placed on protein batteries, a novel concept that utilizes seafood waste as a sustainable source for energy storage. The paper elaborates on the processes involved in transforming fish waste into suitable materials for battery electrodes and evaluates the performance of these protein batteries in terms of efficiency, stability, and capacity. Through a structured analysis of recent advancements, this review underscores the potential of biomass-derived materials in addressing sustainability challenges while advancing energy storage technology. [ABSTRACT FROM AUTHOR]

Fisher-shark conflict is occurring at Lord Howe Island, Australia due to high levels of Galapagos shark (Carcharhinus galapagensis) depredation (where sharks consume hooked fish) and bycatch. Depredation causes costly loss of target catch and fishing gear and increased mortality of target species, and sharks can be injured or killed when bycaught. This study applied acoustic telemetry and vessel tracking from 2018 to 2021 to identify; (1) how the movements of 30 tagged sharks and activity of six fishing vessels overlapped, and (2) where key 'hotspots' of overlap occurred. Fisher surveys were also conducted to collect information about mitigating shark interactions. Residency index analysis indicated that three sharks tagged at a fish waste dumping site had markedly higher residency. Core home ranges of sharks overlapped with higher fishing activity at four 'hotspots'. Statistical modelling indicated positive linear effects of fishing activity and bathymetric complexity on shark detections and tagged sharks were present for 13% of the total time that vessels were fishing close to acoustic receivers. Spatio-temporal overlaps between shark movements and fishing activity could potentially have occurred because sharks learned to associate fishing vessels with food (i.e. hooked fish) and because fishers and sharks utilise highly productive shelf edge areas, however more research is needed to investigate these relationships. Fishers reported that rotating fishing areas and reducing time at each location, fishing deeper than 100 m, and using electric reels and lures instead of bait, reduced bycatch and depredation. The integrated approach used here identified practical methods for reducing fisher-shark conflict, improving socio-economic outcomes for fishers and conservation prospects for this unique shark population. [ABSTRACT FROM AUTHOR]

Bullseye and Pacu fish processing waste were valorized through its conversion into functional protein isolates, followed by the utilization of recovered proteins to supplement oat-based cookies at different levels (0, 2, 4, 6, 8 and 10 g/100 g) and baking temperatures (100, 150, 170, 180, 190 ˚C). With different replacement ratios and baking temperatures, the best selection was made at (4 and 6%) and baking temperatures (160 and 170 ˚C) for BPI (Bullseye protein isolate) and PPI (Pacu protein isolate) based cookies, respectively based on sensory and textural characteristics. The developed products were analyzed for its nutritional, physical, textural, and sensory quality. No significant differences were found in the moisture and ash contents of the cookies from different lots, while the protein content was highest for cookies with 6% PPI. The spread ratio was lower reported for the control cookies compared to the fish protein isolate-based counterpart (p < 0.05), and it decreased with increasing thickness of cookies. Significantly higher total essential amino acid values were obtained in cookies supplemented with 6% Pacu protein isolates, whereas 4% Bullseye protein isolate-supplemented cookies were higher in total non-essential amino acid content. The total plate count was higher in control cookies (0.35 ± 0.33 cfu/g) compared to fish protein isolate-supplemented cookies. The hardness values were maximum for control group cookies (19.14 ± 0.98 N) compared to protein isolate incorporated cookies (17.22 ± 1.05 N and 16.26 ± 0.9 N). However, the difference among the all-treatment group is not significant (p > 0.05). [ABSTRACT FROM AUTHOR]

The efficiency of native and non-native starter cultures in the production of bio-silage using composite waste from fish and vegetables was studied. An ensilage experiment was conducted in a natural way (without starter culture) of composite waste (fish to vegetable at 80 to 20%) to isolate the native fermentative microflora. An Enterococcus faecalis strain isolated from the natural ensilage of composite waste showed higher efficiency over other commercial LAB strains generally used for ensilation. A total of 60 isolates were screened and characterized biochemically from ensilaged composite waste. Among them, 12 proteolytic and lipolytic positive isolates were identified as Enterococcus faecalis, based on a BLAST search of the 16S rRNA gene sequences. Subsequently, composite bio-silage was prepared by inoculating starter cultures with three (3) treatments T1 (native—Enterococcus faecalis), T2 (non-native—Lactobacillus acidophilus), T3 (a mixture of E. faecalis and L. acidophilus) and compared with control (composite bio-silage without starter culture). The highest non-protein nitrogen (0.78 ± 0.01 mg of N /100 g) and degree of hydrolysis (70.00 ± 0.06% of protein/100 g) was seen in the T3 sample, and the lowest (0.67 ± 0.02 mg of N/100 g and 50.40 ± 0.04% of protein/100 g) was seen in the control. At the end of ensilation, the pH fell (5.95–3.88) in conjunction with the formation of lactic acid (0.23–2.05 g of lactic acid/100 g), and the lactic acid bacteria count nearly doubled (log 5.60–10.60). The lipid peroxidation products PV (0.11–0.41 milli equivalent of oxygen/kg of fat) and TBARs (1.64–6.95 mg of malonaldehyde/kg of silage) were changed within a reasonable range in the following pattern Control > T2 > T3 > T1, which led to oxidatively stable products. The findings revealed that native starter culture E. faecalis, which can be employed as a single or in combination with non-native L. acidophilus, performed better in the bio-ensilation process. Additionally, the finished composite bio-silage can be used as a novel, protein-carbohydrate rich feed component to help manage wastes from both sectors. [ABSTRACT FROM AUTHOR]

The fish gill serves many physiological functions, among which is the excretion of ammonia, the primary nitrogenous waste in most fishes. Although it is the end-product of nitrogen metabolism, ammonia serves many physiological functions including acting as an acid equivalent and as a counter-ion in mechanisms of ion regulation. Our current understanding of the mechanisms of ammonia excretion have been influenced by classic experimental work, clever mechanistic approaches, and modern molecular and genetic techniques. In this review, I will overview the history of the study of ammonia excretion by the gills of fishes, highlighting the important advancements that have shaped this field with a nearly 100-year history. The developmental and evolutionary implications of an ammonia and gill-dominated nitrogen regulation strategy in most fishes will also be discussed. Throughout the review, I point to areas in which more work is needed to push forward this field of research that continues to produce novel insights and discoveries that will undoubtedly shape our overall understanding of fish physiology. [ABSTRACT FROM AUTHOR]

Shrimp head by-product (SHP) has been increasingly studied for applications in bacterial fermentation and the production of secondary metabolites. In this work study, Bacillus velezensis EB.KN15 was grown via fermentation using SHP as a novel substrate on a large scale and its potential fungicidal effect against durian pathogen fungi was evaluated. SHP was found rich in protein content (29.18%) and several mineral elements suitable for EB.KN15 fermentation. The appropriate cultural medium for B. velezensis EB.KN15 growth in the small-scale fermentation using 250 mL-Erlenmeyer flask included 2% SHP/LB (7/3), 0.05% MnSO4, and 0.1% KH2PO4 at 34 °C, pH 7 for 36 h. When scaling up fermentation in a 14 L-bioreactor system, this strain exhibited better productivity (1.2 × 1012 CFU/mL) in a shorter fermentation time (only 10 h). Anti-fungal activity tests revealed for the first time, that EB.KN15 has potential fungicidal effect against Fusarium incarnatum, Phytophthora palmivora, and Fusarium solani with high inhibition values of 70%, 78.95%, and 80%, respectively. Gas chromatography mass spectrometry could identify 11 major volatiles produced by B. velezensis EB.KN15 in the supernatant. The molecular docking indicated effective interaction of these major volatiles with the target protein responsible for F. solani inhibition with good binding energy (DS ≤ 7.1 kcal/mol) and an acceptable root-mean-square deviation value (1.05–1.96 Å). This study suggests that SHP is a new substrate for the fermentation of B. velezensis EB.KN15 and recorded this strain as a novel potential candidate to effectively manage durian pathogen fungi. [ABSTRACT FROM AUTHOR]

Today, the fishery industry plays a crucial role in meeting the global demand for human food. However, the increased production and processing of aquatic animals like fish, shellfish, squids, and bivalves have resulted in a significant amount of waste generation. This waste, which includes fish heads, viscera, skin, bones, scales, exoskeletons, pens, ink, and clam, account for approximately 30–70% of the total aquatic product. The accumulation of this waste not only adds to production costs but also poses a serious environmental challenge. To address these issues, researchers have turned to utilizing fish by-products to extract bioactive compounds such as protein hydrolysate, chitin, chitosan, carotenoid, carotenoproteins, omega-3 polyunsaturated fatty acids, and gelatin. These compounds possess desirable properties such as antioxidant, antimicrobial, and therapeutic effects. As a result, they have grabbed the attention of the food and feed industry for various applications. In this article, we aim to provide a concise review of the bioactivity properties of these compounds and their potential applications specifically in aquaculture and seafood processing. [ABSTRACT FROM AUTHOR]

We reviewed available data regarding the benefits of feed additives for mitigation of ammonia toxicity in fish. We first emphasized the toxic effects of ammonia and the pathways involved in ammonia metabolism in fish. Then, we focused on the roles of different dietary additives on internal ammonia detoxification and/or to counteract the negative effects of ammonia toxicity. A wide range of feed additives has been studied for their benefits in fish under ammonia exposure. Most of these studies focused on the improvement of fish health and growth performance by these additives, but neglected underlying mechanisms of these effects as well as ammonia detoxification. It is necessary to monitor internal ammonia, urea, amino acids levels, ammonia/urea excretion, and enzymes involved in ureagenesis and glutamine formation along with health-related parameters (e.g., antioxidant, immunological, and growth responses) in the future studies to fulfil the knowledge gap. Moreover, the future researches should consider the route of ammonia and supplements administration to obtain reliable and practical data. A little evidence shows that dietary nutrients may interact to change the results of dietary supplementation on ammonia toxicity remediation, which must be considered in the future studies. [ABSTRACT FROM AUTHOR]

Tiger sharks are apex predators with a circumglobal tropical and warm-temperate distribution, with a general lack of population data for the central Indian Ocean. In Fuvahmulah, Maldives, tiger sharks display frequent use of the harbour area, attracted by discarded fish waste. Here, we document the population structure, residency, and reproductive characteristics of the world's largest known tiger shark aggregation in a geographically-restricted area. Using non-invasive methods, photo identification and laser photogrammetry, we identified 239 individual tiger sharks over a 7-year study period. The aggregation was female-dominated (84.5%), with both large juveniles and adults present. Adult females were resighted over the entire study period displaying strong inter- and intra-annual site fidelity. Modelled residency using maximum likelihood methods suggests they spent 60.7 ± S.E. 7.5 days in Fuvahmulah, with a larger aggregation size, shorter residence periods and longer absence periods compared to juvenile females. Prolonged abdominal distensions of adult females indicate they likely stay near Fuvahmulah during gestation and reproduce biennially. Fuvahmulah seems to provide suitable conditions for gestation given the year-round provision of food and warm waters, exhibited by strong site fidelity and temporal residency. Our results show indications of a thriving population within the confines of protected waters. [ABSTRACT FROM AUTHOR]

Fish waste is a major environmental pollution problem and requires costly treatment prior to disposal. Conversion of fish waste to economically important and eco-friendly products will make fishing and fish processing more valuable and sustainable. This study evaluated waste residues from fish processing waste subjected to conventional physical extraction of fish oil for single-cell oil production using oleaginous yeast. Potential application of the single-cell oil to produce biodiesel was evaluated. The treatment containing fish waste residue (5%, w/v) and glucose (20 g/L, w/v) displayed the highest rate (14%) of total lipid generation. The fish waste residue proved to be a good nitrogen source for the oleaginous yeast, Rhodotorula sp. R1. At 15% (w/v) fish waste residue and 20% (w/v) glucose amendment of the medium, the highest biomass production was observed. The yeast bio-oil has a lipid profile like vegetable oils and consists of mainly long-chain fatty acids (between C14 and C24) which are suitable for biodiesel production. The most abundant fatty acids were palmitic acid (C16:0), elaidic acid (C18:1n-9t), and stearic acid (C18:0). FTIR analysis of the transesterification reaction product using the yeast oil confirmed its conversion to biodiesel. Although glucose amendment of medium supported lipid accumulation, it can be replaced with wastes rich in sugars to decrease the cost of single-cell bio-oil production. Results indicate the potential secondary value of fish processing waste in the cultivation of oleaginous yeast for bio-oil and biodiesel production. [ABSTRACT FROM AUTHOR]

Chitosan preparation is a sequential method that involves demineralization and deproteinization followed by deacetylation. In the present study, the effect of different process parameters such as concentration of acid, concentration of alkali, ratio between solid and solvent, reaction time, and temperature for optimization of demineralization and deacetylation processes in chitosan synthesis from Labeo rohita scale was studied. The effects of the above process parameters on chitosan yield (in terms of dry weight and % of moist weight of mass) were carried out using Box–Behnken design (BBD) of response surface methodology (RSM). The optimum condition for demineralization was observed at the ratio of solid to solvent (w/v) of 80 and incubation time of 10 min. Similarly, the optimum condition for deacetylation was revealed at alkali concentration of 15% and incubation time of 20 min. The obtained chitosan is characterized by UV–Visible spectroscopy, FT-IR analysis, SEM, and X-ray diffraction. [ABSTRACT FROM AUTHOR]

Pollution, climate change and waste accumulation are critical societal issues calling for advanced methods to recycle matter and clean polluted ecosystems. Here, we review the use of calcium oxide waste-based catalysts for industrial and environmental applications such as biodiesel production, and pollutant degradation and removal. Catalysts can be produced from mud clam shell, eggshell, spent coffee ground, fish bones waste, marble waste, face mask waste, and snail shell. The preparation of composite catalysts, adsorbents, nanoparticles, and photocatalysts is presented. [ABSTRACT FROM AUTHOR]

Fish gelatin is a promising polymer for creating plastics derived from agro-industrial waste, offering a sustainable alternative to single-use plastics. This research aimed to develop fish gelatin films that can be used to replace conventional single-use plastics employed in food packaging. Specifically, our focus was on reducing the high hydrophilic behavior of fish gelatin films which limits their possible applications. To address this, mono-, bi-, and tri- layer films were fabricated from fish gelatin and amylopectin. The fish gelatin was cross-linked with the enzyme transglutaminase to reduce its hydrophilicity achieving two levels of cross-linking: 40 ± 2%, and 65 ± 4%. Micrographs confirmed crack-free films and bilayer/trilayer formation. The cross-linked films exhibited reduced solubility: about 30% in monolayer and 40–67% in bilayer and trilayer films compared to pure protein films. Regarding the water vapor transmission rate, the highly cross-linked trilayer film displayed a value of 0.95 g/m2 h which is significantly lower than pure protein films (2.89 g/m2 h) and amylopectin films (9.37 g/m2 h). Additionally, Young's modulus and the thermal stability were improved with the lamination. These results suggest an effective method for manufacturing films from fish waste, which could contribute to a circular economy for the fishing industry. Enhanced water resistance also makes the films potentially suitable for sustainable biopolymer-based active food packaging. [ABSTRACT FROM AUTHOR]

The special issue of Environmental Science & Pollution Research focuses on the theme of "Valorization of Agroindustry and Seafood Waste Towards a Blue Economy," highlighting innovative research on transforming waste into valuable resources. Articles in the issue cover topics such as protein extraction from fish waste, biodegradation of mixed waste, and utilization of crustacean shells through bacterial co-fermentation. The research presented emphasizes the potential of waste valorization in improving aquaculture practices and promoting sustainability, offering valuable insights for the future of environmental science and the blue economy. [Extracted from the article]

World fishery production and its processing generate huge volumes of fish waste which cause significant challenge to public health and urban planning. The objective of this study is to prepare nanocarbon dots using tuna skin waste and to assess their effectiveness as an additive in three epoxy polymer coatings. These coatings will be applied to BIS 2062 boat building steel to study corrosion in marine environments. Fish skin-derived nanocarbon dots (FSCD) were synthesized through hydrothermal carbonization. Spectroscopic evaluation confirmed the presence of multiple fluorophores in FSCD, which suggest that molecule's structure includes a cyclic conjugated carbon core with dangling functional groups such as COOH, C=O, −OH and C–NH at the edges, resulting in blue–green fluorescence. Electrochemical characteristics of FSCD-reinforced commercial epoxy polymer (3 types)-coated BIS 2062 steel demonstrated excellent corrosion resistance in marine environment. The optimum concentrations of FSCD were determined to be 0.05% in bisphenol A and Dobeckot epoxy polymers, and 0.02% in Araldite epoxy polymer, as evidenced by the highest polarization resistance, lowest corrosion current density and capacitance. The nano-FSCD exerted a synergistic influence on pore-free polymerization due to the presence of dangling functional groups such as amines, in addition to the amine-based hardener. Therefore, fish waste-derived carbon dots offer great potential as a cost-effective and eco-friendly anticorrosive additive for epoxy polymers, meeting the majority of requirements in the anticorrosive coating industry. [ABSTRACT FROM AUTHOR]

Landfill leachate contains a significant amount of organic matter, making it a valuable source for CH4 production. However, due to its liquid form, the mono-digestion of leachate could result in a reduced CH4 yield per unit reactor volume. This necessitates its utilization in anaerobic digesters alongside solid waste streams. The objective of this study was to evaluate co-digestion performance of landfill leachate with different wastes using biomethane potential test and assess the optimum combination in terms of CH4 productivity. Modified Gompertz model was used for kinetic characterization. Experiments were held under mesophilic conditions and lasted for 30 days. Among mono-digestion of substrates, landfill leachate exhibited the highest CH4 productivity and yield: 83.17 mL/gVS.d and 793 ± 6.85 mL/gVS, respectively. Fish waste was found to have the lowest energy potential with 350 mL/gVS CH4 yield and 18.24 mL/gVS.d CH4 productivity. CH4 productivities for co-digestion cases ranged from 5.48 to 67.85 mL/gVS.d. Mixing landfill leachate and chicken manure with the same amount on wet weight basis yielded the highest CH4 productivity. On the other hand, inclusion of fish waste consistently resulted in decreased CH4 yield and productivity for all incubations, which suggests that fish waste may not be suitable as a co-substrate for landfill leachate in terms of CH4 production. Monitoring of chemical parameters revealed that buffering capacity of the system and free ammonia formation were the main parameters governing CH4 production. [ABSTRACT FROM AUTHOR]

Biodiesel is a highly promising and viable alternative to fossil-based diesel that also addresses the urgent need for effective waste management. It can be synthesized by the chemical modification of triglycerides sourced from vegetable origin, animal fat, or algal oil. The transesterification reaction is the preferred method of producing biodiesel. However, the non-miscibility of alcohol and oil layer causes excessive utilization of alcohol, catalyst, and a substantial reacting time and temperature. In the current investigation, transesterification of waste fish oil was performed with petro-diesel as cosolvent, under the influence of ultrasound energy. The combination of both techniques is a unique and efficient way to minimize the mass transfer limitations considerably and hence reduces the parameters of the reaction. It is also a sincere effort to comply with the principles of green chemistry. The optimum reaction conditions were obtained using response surface methodology (RSM) that were as follows: molar ratio of methanol to oil 9.09:1, catalyst concentration of 0.97 wt%, cosolvent concentration of 29.1 wt%, temperature 60.1℃, and a reacting time 30 min. Under these listed conditions, 98.1% biodiesel was achievable, which was in close agreement with the expected result. In addition, the cosolvent removal step from the crude biodiesel was also eliminated as it could be employed as a blended fuel in CI engines. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the influence of enzymatic treatment with transglutaminase on gelatin films derived from Tambaqui skin. The gelatin was extracted through acid extraction, characterized, and subjected to enzymatic crosslinking with transglutaminase at concentrations of 1%, 2%, and 3% (w/w). The optimal conditions for film production were determined based on gelatin Bloom strength. The films were characterized according to physical, chemical, mechanical, barrier, and thermal properties. The extracted gelatin exhibited a molecular weight distribution of 52 kDa, a viscosity of 2.87 cP, and a Bloom strength of 62.71 g. The Gly–Pro–Hyd content accounted for around 31.72% of the total amino acids. The addition of 3% (w/w) transglutaminase significantly increased the gelatin Bloom strength from 62.71 to 101.6 g. However, transglutaminase crosslinking had no significant effect on film thickness and mechanical properties. On the other hand, it did lead to a significant reduction in solubility from 97.57 to 74.29% and water vapor permeability from 10.28 to 9.54 g.mm/m2.d.kPa. FTIR and TGA analyses suggest no significant alterations in the functional groups or degradation events of the gelatin films. Overall, the enzymatic treatment showed promise in reducing the solubility and water vapor permeability of Tambaqui skin gelatin films. [ABSTRACT FROM AUTHOR]

Collagen is a material which is recognized for its biocompatibility properties, biodegradability and low antigenicity, allowing it to be used for the creation of different materials as composites, scaffolds or hydrogels. However, collagen-based materials fail to provide useful mechanical properties in a final product. In this regard, it has been reported that the addition of metallic ions contributes towards supporting polymer matrices. Thus, the objective of this work was to evaluate the effect of metallic ions incorporation on the mechanical properties of biomaterials based on collagen from Pterygoplichthys pardalis and sodium polyacrylate (PAAS). It was observed that the addition of metallic ions modified the mechanical properties of biomaterials out of collagen and sodium polyacrylate (Co-PAAS). The greatest tensile force was achieved when 0.09 mg of collagen and 0.003 mol of Fe3+/g Co-PAAS were used. On the other hand, the greatest elongation at break was achieved when the biomaterial was synthesized with 0.09 mg of collagen and 0.002 mol of K1+/g Co-PAAS. Also, the highest value for Young’s modulus was found when the biomaterial was synthesized with 0.05 mg of collagen and 0.002 mol of Fe3+/g Co-PAAS and 0.003 mol of K1+/g Co-PAAS. Finally, it was concluded that P. pardalis could be a collagen source for the development of biomaterials due to its electrostatic interactions with metallic ions increasing the mechanical properties of the processed material significantly.Article highlights: Pterygoplichthys pardalis is a tropical fish that could be used as collagen source to develop biomaterials. Collagen, sodium polyacrylate and ionic metals interact to generate a biomaterial with better mechanic properties. Ion Fe3+ generates materials with highest Young’s modulus and tensile force. [ABSTRACT FROM AUTHOR]

In the current study, the physicochemical, engine performance, and exhaust emission of different ternary fuel blends containing waste fish oil (WFO) biodiesel, bioethanol, and petro-diesel have been investigated. WFO Biodiesel was prepared from waste fish oil via transesterification method. Different physiochemical properties including the kinematic viscosity, density, flash point, pour point, cloud point, and heat value have been measured for different fuel blends and compared with the neat petro-diesel. The performance and exhaust emission of engine have been also studied using different fuel blends using a single-cylinder diesel engine in full load condition at 1800 rpm. It was found that the engine torque, engine power, and thermal efficiency of the ternary fuel blends was reduced by 2.45%, 9.25%, 2.35% averagely in comparison with the neat petro-diesel, respectively. The average break specific fuel consumption was also increased by 10.44% compared to the neat petro-diesel. The emission of carbon monoxide (CO), carbon dioxide (CO2), unburned hydrocarbons (UHC), and nitrogen oxides (NOx) was also measured. It was also found that the utilization of ternary fuel blends results in a considerable reduction in CO and UHC emission by 50.55% and 43.87% on average compared to the neat petro-diesel, respectively. The emission of NOx was also increased by 28.25% on average compared to the neat petro-diesel. It was also found that the NOx emission can be adjusted by tuning the WFO biodiesel and bioethanol contents of the ternary fuel blends. [ABSTRACT FROM AUTHOR]

This study develops a set of measures to address the interrelationship among circular waste-based bioeconomy (CWBE) attributes, including those of government strategy, digital collaboration, supply chain integration, smart operations, and a green supply chain, to build a circular bioeconomy that feeds fish waste back into the economy. CWBE development is a potential solution to the problem of waste reuse in the fish supply chain; however, this potential remains untapped, and prior studies have failed to provide the criteria to guide its practices. Such an analytical framework requires qualitative assessment, which is subject to uncertainty due to the linguistic preferences of decision makers. Hence, this study adopts the fuzzy Delphi method to obtain a valid set of attributes. A fuzzy decision-making trial and evaluation was applied to address the attribute relationships and determine the driving criteria of CWBE development. The results showed that government strategies play a causal role in CWBE development and drive digital collaboration, smart operations, and supply chain integration. The findings also indicated that smart manufacturing technology, organizational policies, market enhancement, supply chain analytics, and operational innovation are drivers of waste integration from fisheries into the circular economy through waste-based bioeconomy processes. [ABSTRACT FROM AUTHOR]

Gelatin (G) is a thermoreversible polymer produced by hydrolysis of a structural protein called collagen. Fish scales (mixed freshwater species) were subjected to hydrochloric acid (HCl), sodium hydroxide (NaOH) and both HCl and NaOH pretreatment individually, and gelatin extraction with distilled water was labeled as GA, GB and GC, respectively. The percentage yield of gelatin GB (9.6 ± 0.5%) was higher than GA (7 ± 0.2%) and GC (9 ± 1.4%). Amino acids and imino acids (proline and hydroxyproline) composition confirmed the characteristic nature of collagen. The gel strength of gelatin was affected by the pH of the extraction medium rather than the presence of imino acid composition. Extracted gelatin GA, GB and GC showed ʎmax at 230 nm indicating the peptide bond of gelatin and the presence of five amide bands I, II, III, A and B revealing the intrinsic nature of functional groups C=O, C–N, C–N, N–H and –NH3 stretching vibrations of collagen, respectively. Two diffraction peaks of 2ɵ, one sharp peak around 10° and one broad peak around 20° represent the partially crystalline nature of fish gelatin. The presence of β, α1 and α2 chain at around 200 KDa, 110 KDa and 100 KDa, respectively, confirmed the triple helix nature of the gelatin. Glass transition temperature (Tg) of gelatin GA, GB and GC at 76.3 °C, 72.9 °C and 71.4 °C, respectively, and melting temperature (Tm) of GA, GB and GC at 406 °C, 295.2 °C and 291.7 °C, respectively, were evident through thermal study. The effect of acidic and alkaline pretreatment of fish scale had displayed fibrillar pattern, evenly spaced porous nature and network-like structure of gelatin which was thermally stable up to ~ 300 °C. Hence, waste fish scales have proved to be a cost-effective and environmentally friendly alternative raw material for gelatin production paving the way for safe alternatives for biomedical application. [ABSTRACT FROM AUTHOR]

Baseline data on plastic landing by fishers and monitoring of this is important in evaluating the success of plastic waste management efforts. This study investigated plastic and fish landed by beach seine fishers in Ghana together with the rate of plastic deposition on an adjoining beach. Plastic constituted 31.6% of the total catch and 41.7% of the fish landed by weight. There were significant differences between the average weight of fish (139.58 ± 53.6 kg) and plastic (65.73 ± 14.6 kg) landed per fishing session and the catch per unit effort of fish (183.4 ± 76.7 kg/day) and plastic (88.4 ± 35.2 kg/day). The mean weight of plastic landed per fishing session was higher than the mean weight of each of the 26 species of fisheries. The rate of plastic deposition on the beach was 8.1 ± 2.5 plastic items per m2 per tidal cycle or 0.35 ± 0.11 kg plastic per m2 per tidal cycle with food packs and tableware dominating the deposited plastic. The results suggested ongoing water sachets and plastic bottle recycling in Ghana are yielding results and calls for targeted efforts in plastic food packs and tableware management. [ABSTRACT FROM AUTHOR]

In this study, the abundance of microplastics (MPs) in the Uppanar and Gadilam estuaries in Cuddalore, on the southeast coast of India, is reported. In the estuarine sediments, MP abundance ranged from 36.3 ± 3.39 to 51.6 ± 2.05 particles/Kg dw. Different types of MP shapes, such as fibers (41.7–47.9%), films (21.2–27.2%), and fragments (18.3–25.5%) were observed in the size range of 100–1000 µm. Diverse colours of MPs were observed, among which red (30.1–34.5%) was predominantly noticed in the estuarine sediments. Six polymers were identified by µ-FTIR, among which LDPE (39%) and PP (35%) were dominant. MPs pollution in these estuaries is composed of domestic, industrial, and fishing wastes. Risk assessments show that the area falls under hazard categories I to III, indicating low to high risk. This study improves knowledge on MPs contamination in Uppanar and Gadilam estuaries and provides impetus for further research to identify the actual sources and impacts of MPs on aquatic systems along the east coast of India. [ABSTRACT FROM AUTHOR]

In this study, the growth, biomass, and bio-constituents of Chroococcus sp., Haematococcus pluvialis, Dunaliella sp., Coelastrella saipanensis, and Chlorella sp. grown in dairy wastewater and fish waste as nutrients were assessed. As both wastes constitute organic and inorganic nutrients, dairy wastes contain proportionately higher amount of K, Na, and sugars than the fish wastes which contains nitrogen, phosphorus, organic carbon, and protein as nutrients. Algae grown among different dilutions of wastes showed that medium supplemented with 50% dairy waste significantly increased the growth, biomass, carbohydrates, and protein content in algae such as Chroococcus sp., H. pluvialis, C. saipanensis, and Chlorella sp., whereas in Dunaliella sp. by addition of 10% dairy waste showed maximum growth and other bio-constituents, but 50% fish waste used for Chroococcus sp., C. saipanensis, and Chlorella sp. growth medium. A total of 25% fish waste used for Dunaliella sp. and H. pluvialis. The enhanced growth and bio-constitute accumulation in microalgae grown using waste nutrients was further confirmed by increased growth observed in nitrogen-depleted waste supplemented medium over control (only medium). Despite increased growth and bio-constituent accumulation in algae grown by waste nutrients, Chroococcus sp., H. pluvialis, and Chlorella sp. grown by waste nutrients showing significant decrease in chlorophyll content were found as efficient in absorbing waste nutrients by heterotrophic mode. The Chroococcus sp. and Dunaliella sp. grown in dairy waste and Chlorella sp., H. pluvialis, and C. saipanensis grown in fish waste accumulated intracellular non-polar storage lipids identified through fluorescence study were recognised as suitable biorefinery candidates for lipid sequestration by utilizing waste nutrients, besides high value pigments. This study concludes that dairy and fish wastes are cost-effective nutrient resource for enhanced growth, bio-constituents, lipids, and high values pigments accumulation in microalgae as biorefinery. [ABSTRACT FROM AUTHOR]

This is the first such study in which a gelatin extract obtained from carp skins enriched with dry herbs (thyme or rosemary) has been prepared. Extracts prepared in such a manner were added to furcellaran coatings. Coatings were tested for their mechanical properties and the obtained results showed that the control coatings, and those with the addition of rosemary, had the best strength-related parameters. A new ready-to-cook product was evaluated with regard to the preservative effects of carp skin gelatin coatings containing rosemary and thyme extracts in terms of pH, biogenic amine formulation, microbial changes and sensorial characteristics. The coatings with added rosemary proved effective in inhibiting the formation of biogenic amines, and slowing down the microbial deterioration of carp fillets (reduction by 0.53 and 0.29 log cfu/g). The evaluated herb coatings changed the characteristic taste of fish. Interestingly, the coatings emphasized the natural saltiness of fish meat. [ABSTRACT FROM AUTHOR]

The purpose of this study was to see how differences in the C/N ratio affected the microbial decomposition of composite waste from fish and vegetables, which led to the development of composite silage. In this experiment, T1 (100% FW), T2 (100% VW), and T3 (80% FW + 20% VW), along with carbohydrate (15% Jaggery) and starter culture Lactobacillus acidophilus (MTCC 10,307), were used for the microbial ensilation. Variations in proximate composition, chemical changes (pH, TTA), the proteinous nitrogenous fraction (C/N ratio, NPN, DH), lipid oxidation (TBARs), and microbial total LAB & Fungal counts (log cfu/g) were investigated on every alternative day during the three weeks of microbial ensilage at room temperature (30 ± 2 °C). A significant (P < 0.05) decrease in carbon/nitrogen ratio was observed among T1 (9.36–7.50), T2 (22.31–20.27), and T3 (11.96–7.0) during the ensilage of three weeks in room temperature (30 ± 2 °C). In all the treatments, titratable acidity and LAB (107–1010 log cfu /gm) show increasing trends which are correlated with the decrease in carbon/nitrogen ratio and pH value (< 4.5) after 72 h of ensilage. Nitrogenous fraction (NPN, DH), and lipid peroxidation product (TBARs) change significantly (P < 0.05) in the following trend T1 > T3 > T2, respectively. Yeast and mould counts were absent in all the samples. The results indicated that the carbon/nitrogen ratio substantially affects the microbial ensilage of fish and vegetable waste. The best combination of the C/N ratio can effectively ensilage these two different stream wastes as animal feed ingredients in the aquaculture industry. [ABSTRACT FROM AUTHOR]

Acid Yellow 36 (AY36) dye is a synthetic azo dye that is excessively used in various industries, causing hazardous environmental effects. The main target of this study is the preparation of self-N-doped porous activated carbon (NDAC) and the investigation in eliminating the AY36 dye from the water solution. The NDAC was prepared by mixing fish waste (60% protein content) which was considered a self-nitrogen dopant. A combination of Fish waste, sawdust, zinc chloride and urea with a mass ratio (5:5:5:1) was submitted to hydrothermal process at 180 °C for 5 h followed by pyrolysis for 1 h under N2 stream at 600, 700, and 800 °C. Fabricated NDAC was qualified as an adsorbent for recovering AY36 dye from water using batch trials. The fabricated NDAC samples were characterized by FTIR, TGA, DTA, BET, BJH, MP, t-plot, SEM, EDX, and XRD methods. The results showed the successful formation of NDAC with nitrogen mass percentage content (4.21, 8.13 and 9.85%). The NDAC prepared at 800 °C had the largest nitrogen content (9.85%) and was labeled as NDAC800. This later had 727.34 m2/g, 167.11 cm3/g, and 1.97 nm for specific surface area, the monolayer volume and the mean pores diameter respectively. By being the more efficient adsorbent, NDAC800 was chosen to test AY36 dye removal. Therefore, it is selected to investigate the removal of AY36 dye from aqueous solution by varying important parameters such as solution pH, initial dye concentration, adsorbent dosage and contact time. The removal of AY36 dye by NDAC800 was pH-dependent, with the optimum pH value 1.5 giving 85.86% removal efficiency and 232.56 mg/g maximum adsorption capacity (Qm). The kinetic data exhibited the best fit model with the pseudo-second-order (PSOM), while the equilibrium data fit well with the Langmuir (LIM) and Temkin (TIM). The mechanism of AY36 dye adsorption may be ascribed to the electrostatic contact between the dye and the available charged sites on NDAC800 surface. The prepared NDAC800 may be considered as an efficient, available, and eco-friendly adsorbent for AY36 dye adsorption from simulated water. [ABSTRACT FROM AUTHOR]

Improper management of fish waste is one of the factors that makes Philippine fisheries unsustainable. A considerable portion of fish waste is produced in wet markets where bulk of fish products are sold. A comparison of existing practices in different municipalities can indicate the best points of intervention and identify existing traditional practices that can be promoted. This study interviewed stakeholders of the fisheries industry and collected information at the market level to determine existing fish waste management systems. From the responses gathered, the average daily production of fish waste in Philippine wet markets was 70.3 + 0.93 kg, with no significant differences across locations (p = 0.2501). Of the fish waste produced, 32.3 + 1.33 kg per wet market were disposed of, 18.9 + 0.81 kg were sold, and 19.1 + 1.15 kg were given away to stakeholders who re-use the fish waste. A significantly greater proportion of fish waste in rural areas were re-used compared to Metro Manila (p = 0.0311). Incentivizing innovations that maximize the use of derived fish waste at the municipal level, and promoting existing traditional practices, can prove effective in contributing to the Philippine circular economy while providing alternative sources of income for the stakeholders of the fisheries industry. [ABSTRACT FROM AUTHOR]

In the present work, the biofuels were prepared from chicken slaughter waste, broiler excrete, and fish waste through the pyrolysis process. The effect of prepared biofuels was identified and evaluated in terms of the emission parameters on a four-stroke, single-cylinder diesel engine test bench. Customized fuels are prepared by blending of oil derived from chicken slaughter waste, broiler excrete, and fish waste at 10% volume with diesel at 90% volume to conduct the experiments. This oil is restricted to 10% volume for blending with diesel owing to its inferior heating value. This work also focuses on reducing the direct environmental pollution by preventing the dumping process of slaughter waste, broiler excrete, and fish waste which causes bad odor and soil pollution. The influence of oil derived from chicken slaughter waste, broiler excrete, and fish waste and diesel blend was compared with conventional diesel. Test results demonstrated that the CO (30.52%), HC (25.41%), and NO (22.84%) emissions of chicken slaughter/broiler excrete/fish waste biofuels and diesel blends reduced extensively than diesel at full load. Further, the CO2 emissions of fish waste and diesel blend are increased by 30.52% at 25% load condition, and at 100% load, it increased by 23.80% than diesel. The attained results shall play a significant role to execute analysis concern to various alternative fuels to lower engine emission patterns. [ABSTRACT FROM AUTHOR]

The available models that predict total ammonia nitrogen concentration ([TAN]) in anaerobic digestion (AD) overestimate or underestimate the inhibition effect of [TAN], making them impractical to be implemented in full-scale digesters. Therefore, this study was conducted to establish a general and simple model to predict [TAN] with a decent predictive power by implementing machine learning modeling approaches. The experiment was conducted on AD reactors treating fish waste with three different feeding strategies and digestion times. Of 324 data entries, 80% and 20% were used for model training and testing. Cross-validation was also performed to determine the flexibility level and estimate the accuracy of the test dataset. Nine individual models were trained independently on training dataset, and the best-tuned models were inputted into voting regressor (VR) algorithm. VR outperformed other trained models with RMSEtest = 0.15, R2test = 0.98, and 4.76% of model error. The model's generality was also confirmed by high coefficient of variation of several features used for model establishment, representing the complexity of AD process. Therefore, this model can be implemented to predict [TAN] in other AD systems, especially in systems treating high protein contents. It will be beneficial to maintain stability and improve the efficiency of AD. [ABSTRACT FROM AUTHOR]

The amount of human-origin litter in sea surface water, sediment, and beaches has been increasing for decades. Initially described in marine coastal systems in the 1960s, marine litter (ML) is nowadays commonly observed in all marine systems. There is even a gigantic island consisting of garbage in the gyre area of the Atlantic Ocean. In relation to this significant problem, ML was collected from seven stations on beaches along the Dardanelles for the first time in the period May 2017–May 2018 and was seasonally and regionally analyzed in terms of densities and weights. ML was categorized by material type (plastic, rubber, paper, etc.) and field of use (mixed packaging wastes, personal use products, fishing wastes, etc.). Total numbers and weights of ML during the study were 5751 items and 115.7 kg in an area of 15,980 m2, respectively. Density and weight of ML ranged from 0.050 to 1.182 items/m2 and from 0.446 to 78.46 g/m2, respectively. The main ML component was plastic items in terms of both density (90.95%) and weight (53.76%) according to material type. Additionally, mixed packaging wastes (MPW) were the most common ML items in terms of density (82.14%) and weight (49.38%) according to usage. According to the clean-coast index, while Kilya (St.2) and Kepez (St.5) beaches were dirty, Seddulbahir (St.1) beach was clean. The beaches in other stations were neither dirty nor clean (medium) according to the index. At the end of the study, suggestions for a regional strategy were made. [ABSTRACT FROM AUTHOR]

This article assesses strategies for managing the economic returns to an aquaponics production system with joint products of lettuce and tilapia. Experimental data from Brazil that varied fish stocking density and the fish feeding rate are analyzed using nonparametric efficiency testing methods to identify potentially profitable technologies and their sensitivities to prices of inputs and outputs. Plants and fish production are symbiotic in an aquaponics system, with fish waste providing nutrients for plant growth and plants helping maintain water quality for the fish via filtration. The optimal input/output mix among alternatives is identified, and sensitivity analysis is used to assess the price ranges around recent market conditions (0.18 R$/tilapia fingerling, 2.8 R$/kg for fish feed, 20 R$/kg for juvenile fish, and 1.57 R$/kg for lettuce) over which that technology choice remains optimal. The configuration of production controls is robust to price changes. Results show that at low fish stocking densities (100 fish/m3), the effluent in the water provides insufficient nutrients to plants. In addition, early lettuce harvests (before 26 days) are generally less efficient than treatments that allow more time for plant growth. Sensitivity analysis indicates that the optimality of the identified configuration of production controls is robust with respect to input and output prices. [ABSTRACT FROM AUTHOR]

Olive flounder (OF) and Starry flounder (SF) are the commonly cultured fish species in the South Korea East Sea. Evaluation of whether those dead fish wastes are suitable for anaerobic digestion is required. The aim of this study was to characterize the physicochemical properties of each fraction which was flesh, bone, head, skin, viscera, and whole fish OF and SF and evaluate their biochemical methane potential (BMP). The results showed that both dead fish species' wastes mainly contained proteins (48–75% of volatile solids [VS]) and lipids (19–40% of VS), whereas carbohydrates were little found (0.7–5% of VS). The BMP of each fraction was investigated in a mesophilic condition and the substrate-to-microbe ratio was 0.5 g CODsubstrate/g VSSinoculum. The results showed that the bone fractions in both OF and SF showed the highest methane yield with 0.37 and 0.38 L CH4/g CODadded, respectively whereas the viscera fractions of both fish species showed the lowest methane yield with 0.20 L CH4/g CODadded. The modified Gompertz model showed that the longest lag phase was observed in the bone fractions of OF and SF with 1.59 d and 2.62 d and the shortest lag phase was in the viscera fraction of OF and SF with 0.37 d and 0.58 d, respectively. The energy recovery of every fraction of both species ranged 43–69%. Principal component analysis indicated that the viscera fraction of OF and SF had different characteristics from the other fractions. This study suggests that dead fish wastes can be considered for biogas production. [ABSTRACT FROM AUTHOR]

Glycosaminoglycans (GAGs) are bioactive polysaccharides or glycoconjugates found in the fish waste having significant health impacts. In the present study it has been attempted to extract GAGs from mackerel fish waste through chemical and enzymatic methods. Further, the extracted GAGs (e-GAGs) were analyzed for their composition (uronic acid, total sugar & sulfate), chemical characterization was carried out through techniques of scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) & Proton NMR. Further, probable major GAGs present was identified by enzymatic digestion. The biological potential of the extracted glycoconjugate was assessed further through in-vitro and in-vivo studies. In-vitro biological activity showed good lipase inhibition (IC50, 2.6 mg/mL) and bile acid binding properties (dose-dependent). Lipid accumulation lowered in the e-GAGs differentiated 3T3L1 preadipocyte cells have also been observed. The high fat fed animal (in-vivo) study showed ameliorative effect via reducing blood sugar∼1.28↓, lipid profile↓, plasma insulin∼3.5↓, improved glucose tolerance, and homeostatic model assessment for insulin resistance (HOMA-IR, ∼3.0↓). Furthermore, elimination of bile acid (BA) due to GAG-BA binding properties resultant in removal of elevated fecal triglyceride and cholesterol suggesting its lipid lowering activity. Regulation of various proteins linked to carbohydrate and lipid metabolism including fatty acid synthase (FAS), low density lipoproteins receptor (LDL-R), 7α-hydroxylase, glucose transporter-4 (GLUT4) and Peroxisome proliferator- activated receptor gamma (PPAR-γ) were significant (p < 0.05) with e-GAGs treatment when compared to HFD group. Thus, the e-GAGs showed potential hypolipidemic activity through elimination of bile acid binding property together with regulating the specific protein related to obesity and its associated complications. [ABSTRACT FROM AUTHOR]

Alternate fuels are in great need as the world's natural resources are depleting with continuous consumption. Furthermore, with a continuous increase in the use of conventional fuel which emits a large number of harmful pollutants to the environment and thus increasing global warming, the need for alternative fuel is in great need. This investigation thus focused on the impact identification on the use of biodiesel from fish waste-based biodiesel [BDWFO (Bio-Diesel of Waste Fish Oil)] with Nanoparticles in single cylinder water cooled IC engine. The fish wastes in fish processing industries/fish markets are used to produce oil and its biodiesel is produced by the transesterification method. The individual BDWFO, Diesel, and blends of 20% of BDWFO were tested with the engine. Then another two combinations of fuel created 200 ppm of 40 nm Aluminium Oxide nanoparticles (AN) mixed with BDWFO, blends of 20% of BDWFO. These five fuels were considered to study the engine performance, combustion, and emissions from the exhaust. The experimental results confirmed the presence of aluminium oxide nanoparticles in BDWFO provides improved engine performance and reduced emissions from exhaust gas except for CO2. [ABSTRACT FROM AUTHOR]

Fish processing industries worldwide are discarding million kilograms of fish waste per year. The disposal of these wastes is an important handicap in fish processing industry. The thick eel skin is considered a waste product in the fish processing industry and in the home and is usually converted into low market-value products. The aims of this study were to evaluate the variations in the general chemical composition and amino acid content of eel skin in relation to body weight. The moisture content decreased and the lipid content increased with the weight of the eels. Eel skin had a high protein content, which did not vary significantly with eel weight. Glycine was the most abundant amino acid. The predominant essential amino acid was leucine. The smaller eels contained higher levels of threonine, valine, isoleucine, leucine, lysine, glutamic acid and tyrosine than the other groups. The larger eels contained higher levels of methionine, hydroxyproline, glycine, arginine, alanine and proline than the other groups. The protein indices showed that the skin from smaller eels was of higher nutritional quality. [ABSTRACT FROM AUTHOR]

Introduction: The fishing industry has one of the largest influences on economic development in the Colombian Pacific region. Fishmeal is a product of this industry; however, the shelf-life of fishmeal is limited by its lipid content. This study aimed to transform fish waste through fermentation to obtain fishmeal with high digestibility and a low lipid content as a usable product in animal nutrition. Methods: The bacteria, Pediococcus acidilactici (C20) and Staphylococcus warneri (BL24), of the lactic acid and lipolytic groups, respectively, were selected as fermentative microorganisms. Four treatments were established (T1: control (endogenous bacteria), T2: inoculum with C20, T3: inoculum with BL24, and T4: mixed inoculum (BL24/C20)), and fermentation lasted 4 days. The temperature was maintained at 35 °C under the relative humidity of the city of Cali. The fermentation kinetics were evaluated by analyzing the pH, fat content, protein content, and substrate consumption. At the end of fermentation, treatments had significant differences (p < 0.05) with T3 and T4 where reduced the lipid content by 25.26% and 31.77% respectively. Results: Fishmeal with T3 treatment had high protein digestibility, lower peroxide value and a good amino acid profile; therefore, fermentation with lipolytic bacteria can reduce the fat content of fishmeal. Conclusion: The results obtained in this research demonstrate that fermentation process it can be a very useful tool to improve the nutritional quality of fish products which are used as a protein source in feed. [ABSTRACT FROM AUTHOR]

Collagen is a promising candidate for food and pharmaceutical applications due to its excellent biocompatibility, low antigenicity, and controlled biodegradability; however, its heavy price restricts its utilization. Fish scales generated during the processing are generally regarded as waste material and an environmental pollutant, though they are a promising source of collagen. In the present study, Cirrhinus mrigala scales were demineralized and extracted for acid-soluble collagen (ASC) using acetic acid, with a collagen yield of 2.7%. UV–Vis spectra, SDS-PAGE, FTIR analyses, and amino acid composition confirmed the type I nature of the collagen extracted. The denaturation temperature of the collagen was found to be 30.09 °C using differential scanning calorimetry (DSC). The collagen was highly soluble at acidic pH and lower NaCl concentrations while its solubility was lowered in alkaline conditions and NaCl concentrations above 0.5 M. The collagen exhibited good emulsifying potential with an emulsion activity index (EAI) and emulsion stability index (ESI) of 21.49 ± 0.22 m2 g−1 and 15.67 ± 0.13 min, respectively. Owing to the good physicochemical characteristics of the extracted collagen, collagen-chitosan-neem extract (CCN) films were prepared subsequently which showed good antimicrobial activity against Bacillus subtilis NCIM 2635, Staphylococcus aureus NCIM 2654, Escherichia coli NCIM 2832, and Pseudomonas aeruginosa NCIM 5032, suggesting the potential of collagen in the development of antimicrobial films. These results demonstrate that the collagen from fish waste could be valorized and used effectively along with chitosan and neem extract for the synthesis of novel biodegradable films with antimicrobial efficacy. [ABSTRACT FROM AUTHOR]

In this study, a comparative structural and bioactive analysis of collagen extracted from the skin of bony and cartilaginous fishes. The acid-soluble method was followed to extract the collagen from Hypophthalmichthys molitrix (silver carp) and Rhizoprionodon acutus (milk shark) followed by purification using Ion exchange chromatography. A higher yield of collagen was obtained from the skin of SCsk (69.45%) as compared to SHsk (55.29%). SDS PAGE displayed the characteristic α, β bands of the collagen type1. The native conformation and secondary structure stability of collagen were confirmed by FTIR, XRD and CD studies. The SEM micrographs exhibited the layered and fibrillar nature of the collagen from SHsk and SCsk, respectively. Relative solubility and thermal denaturation analysis showed SCsk to be more stable, but SHsk could withstand higher temperatures. 53.65% of antioxidant activity was observed in SCsk collagen as compared to SHsk (45.9%). Haemocompatibility, cell viability and adhesion results also displayed silvercarp skin to be a better source than Shark skin collagen. The results establish the potential of silver carp collagen as a biomaterial that can have many commercial applications in tissue engineering, cosmetics and food industries. [ABSTRACT FROM AUTHOR]

India ranks second in the harvesting and production of fish. The discard of fish is near about 20–40% of total fish weight. Therefore, a huge amount of fish waste is being generated, leading to the need for its better utilization. Protein hydrolysates from Indian mackerel fish waste were made by extracting protein using alkali and hydrolyzing them with the alcalase enzyme. For protein extraction and hydrolysis processes, factors such as temperature, stirring speed, pH, time, solvent load, and enzyme concentrations were optimized using empirical equations with response surface methodology. A protein yield of 75% was recorded to be the highest at a solvent load of 64%, at 490 rpm stirring speed, and for a time duration of 80 min. Alcalase enzyme showed the highest degree of hydrolysis, i.e., 71.72%, at an enzyme to substrate concentration of 40 U/mL, at 50 °C with pH 7.7 for 40 min. Fish waste protein hydrolysates having a high antioxidant and anti-hypertensive activity were successfully prepared from the waste. [ABSTRACT FROM AUTHOR]

This study was conducted to compare the qualitative properties of silages prepared from rainbow trout viscera and extracted oils. Silages under acidic and fermentation processes were prepared and kept at room temperature (24 ± 2 °C) for 30 days. Experimental treatments include acid treatment with 3% (w/v) lactic acid added to raw wastes (AL), acid treatment with 3% (w/v) formic acid and propionic acid (1:1) added to raw wastes (AFP), fermentation treatments with 5% (w/v) MRS broth culture medium containing 107 CFU/ml Lactobacillus plantarum bacteria and 15% (w/w) sugar beet molasses added to raw (FR) and cooked (FC) wastes, respectively. Qualitative evaluation of silages during storage was performed by chemical and microbial experiments. The qualitative evaluation of the oils extracted from the silages was performed on days 0, 7 and 30 using the peroxide value test. The changes in total volatile basic nitrogen (TVB-N) during storage had an increasing trend (P ˂ 0.05), and the highest rate on day 30 of storage (90.1 ± 22.82 mg N/100 g) was related to the prepared treatment by formic acid and propionic acid. The level of free fatty acids was increased (P ˂ 0.05) during storage and was higher in fermentation treatments than in acid treatments. In all treatments, the peroxide value reduced (P ˂ 0.05) at the end of the storage. Among measured volatile fatty acids, the highest level was related to acetic acid. The results of this study showed that the fermented silage could be better for using extracted oil and the acidic silage as a source of using protein in feed. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate biocompatibility of hydroxyapatite (HAP) from fish waste using in vitro and in vivo assays. Fish samples (whitemouth croaker - Micropogonias furnieri) from the biowaste was used as HAP source. Pre-osteoblastic MC3T3-E1 cells were used in vitro study. In addition, bone defects were artificially created in rat calvaria and filled with HAP in vivo. The results demonstrated that HAP reduced cytotoxicity in pre-osteoblast cells after 3 and 6 days following HAP exposure. DNA concentration was lower in the HAP group after 6 days. Quantitative RT-PCR did not show any significant differences (p > 0.05) between groups. In vivo study revealed that bone defects filled with HAP pointed out moderate chronic inflammatory cells with slight proliferation of blood vessels after 7 and 15 days. Chronic inflammatory infiltrate was absent after 30 days of HAP exposure. There was also a decrease in the amount of biomaterial, being followed by newly formed bone tissue. All experimental groups also demonstrated strong RUNX-2 immoexpression in the granulation tissue as well as in cells in close contact with biomaterial. The number of osteoblasts inside the defect area was lower in the HAP group when compared to control group after 7 days post-implantation. Similarly, the osteoblast surface as well as the percentage of bone surface was higher in control group when compared with HAP group after 7 days post-implantation. Taken together, HAP from fish waste is a promising possibility that should be explored more carefully by tissue-engineering or biotechnology. [ABSTRACT FROM AUTHOR]

We assessed the quality of Andes-Amazonia streams in Ecuador impacted by gold mining (GM), discharges from inefficient sewage network in urban areas (UA), wastes from fish farming (FF) and from non-functional landfill (LF) and other few threats (FT). We selected three lines of evidence (LOE) that were used separately and integrated into a index: water quality (WQI) and macroinvertebrate community (AAMBI) indices and phytotoxicity tests. Streams affected by UA and LF had the lowest scores to WQI and phytotoxicity, and by GM had the lowest scores to AAMBI. Macroinvertebrate absence in GM should be considered as a warning signal of long-term mining impacts in the area. The integrated LOE index showed that sites with identified threats had 30%–53% stream quality decline compared to FT sites. The use of the selected LOE seems to be a useful tools for long-term monitoring and evaluation of this sensitive aquatic ecosystem. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the estimation and management of fish and shrimp wastes in Bushehr province. Two-part questionnaire including the demographic information, and fish and shrimp waste disposal method were completed for 91 stores and 636 households. The quantity of generated wastes was estimated based on the 3 different Scenarios. In addition, the waste generation factor were calculated for common fish and shrimp species. Results showed the waste generation factor for fish and shrimp equal to 32.67 and 42%, respectively. The total quantity of fish- and shrimp-generated wastes in Bushehr province was estimated to be 29,388 tons per year, of which the quantity of generated waste by stores and by households was 3731 tons per year (16 ton per capita per year) and 8804 tons per year (34 kg per capita per year), respectively. The remaining quantity is related to other unaccounted sectors such as fish industries. Moreover, the biogas production potential from an anaerobic digestion were estimated 2,675,400 m3 per year, which is equivalent to 16,052 MWh. In addition, the biodiesel production potential was obtained equivalent to 19 kt, which is about 4.2% of the total diesel fuel requirement of the province in 2016. [ABSTRACT FROM AUTHOR]

Generally, the coating properties of polymeric compounds are enhanced by using nanomaterials as fillers which are non-biobased. In this project, the hydroxyapatite (HAP) was obtained from waste fish scales and the biobased hyperbranched polyol (HyBP) was synthesized from castor oil. The series of nanocomposites were prepared by adding various amounts of HAP (0.5% wt, 1% wt, and 2% wt) in HyBP along with isophorone diisocyanate (IPDI) (maintaining the NCO:OH, ratio at 1.2:1). These mixtures were coated on mild steel panels and glass plates. The synthesized HyBP was characterized by FTIR, 1HNMR, and 13CNMR techniques. The HAP was characterized by FTIR, FESEM, and XRD techniques. The surface morphology of prepared nanocomposites was studied by FESEM, XRD, and AFM techniques. The nanoparticle size was determined by TEM technique. The thermal behavior of nanocomposites was studied by TGA technique. The coating properties were determined by impact strength, crosscut adhesion, and flexibility test. The corrosion properties of the coatings were determined by the immersion test as well as electrochemical test. [ABSTRACT FROM AUTHOR]

Sexual segregation in feeding strategies has been widely reported in seabirds. Most seabirds occupy wide breeding distributional ranges, and dissimilar ecological settings may result in distinct environmental pressures on males and females leading to geographical differences in sexual segregation. Using GPS loggers and stable isotope analysis of whole blood (δ15N, δ13C), we assessed the occurrence of sexual differences in Kelp Gull (Larus dominicanus) foraging trip parameters, habitat use, isotopic niche and diet during the incubation period at three breeding locations in Argentina characterized by different foraging contexts. At Islote Arroyo Jabalí Este, sexual differences were found in trip parameters and habitat use mainly associated with a significantly higher use by males of a refuse dump as foraging site. However, their isotopic niches were similar with both sexes consuming mostly recreational fish waste, suggesting it was mainly obtained by males at the dump and by females at shoreline areas used by fishers. At Punta Tombo, there were no sex differences in trip parameters nor in the main prey consumed consisting of fishery discards, although females used more shoreline areas and males presented a significantly larger isotopic niche width. In contrast, at Isla Vernaci Este, males and females showed similar trip parameters, habitat use, and isotopic niche width and diet composition. Results show geographical differences in the degree of sexual segregation, which may result from differences in the availability of local food resources, particularly anthropogenic food subsidies. [ABSTRACT FROM AUTHOR]

Hydrothermal carbonization (HTC) is a promising technology for the management of lignocellulosic wastes for which it has been frequently employed. However, HTC is also suitable to treat non-lignocellulosic wastes such as seafood wastes. In this study, HTC of fish and shrimp wastes were carried out using microwave and conventional reactors. The resulting end product fractions were solid hydrochar and the liquid biocrude liquor. Bio-oil was extracted by leaching the hydrochar in acetone, and bio-crude liquor was subjected to dichloromethane extraction. Subsequently, these extracts were analyzed by gas chromatography-mass spectroscopy. The biocrude liquor was found to be composed primarily of heterocyclic nitrogen containing compounds such as diketopiperazines and pyrazines. As for the bio-oil extracted from the hydrochar, fatty acids and sterols formed the major fractions. Taken together, HTC produces commercially attractive components in the liquid phase in addition to the solid hydrochar, and thus, could have multifaceted benefits and applications. [ABSTRACT FROM AUTHOR]

A considerable quantity of waste is being generated from fish markets and harbors of coastal regions in India. Presently, there is no systematic and sustainable ways of disposal which leads to unscientific handling and dumping in landfills. Upon considering the bottlenecks associated with the anaerobic digestion of fish waste (FW) as sole substrate, co-digestion with vegetable wastes (VW) could be an effective alternative to mitigate the problem along with simultaneous treatment of two different waste streams. In this study, an attempt has been made to examine the co-digestion efficiency of FW with VW for which three trials viz., T1 (mono-digestion of VW), T2 (mono-digestion of FW) and T3 (co-digestion of VW and FW) were conducted to analyze the biomethane production potential, degree of biodegradability and pH stability. From the obtained results co-digestion was found to yield 463 ± 6.73 L/kg VSfed of biomethane which is 24.13% and 22.32% higher as compared to VW (373 ± 4.94 L/kg VSfed) and FW (378 ± 4.55 L/kg VSfed) respectively. Maximum biodegradability based on organic carbon destruction was found to be 70% in co-digestion followed by mono-digestion of VW (58.8%) and FW (64%). Prevalence of acidification and ammonification in mono-digestion of VW and FW were reflected by physiological pH of 5.4 ± 0.41 and 8.3 ± 0.32 respectively. In co-digestion process pH was observed to be 7.3 ± 0.70 that indicated high stability and thus enhanced the biomethane yield. Co-digestion of these organic wastes could enhance the efficiency of methane production and therefore presents a unified waste management option. [ABSTRACT FROM AUTHOR]

The issues of heavy metal contamination in water sources have been increasing substantially along with the rapid pace of industrial revolution. Lead, particularly, is one of the heavy metals that received considerable attention lately due to its frequent detection in the environment and hazardous effects. Although conventional water treatment processes had been utilized for ages, it is still a challenge to remove lead in the treatment plant effectively. In line with the advancement of chemistry and nanotechnology, the study on hydroxyapatite (HAp) nanopowder made from fish waste (skin, bones, and scales) has brought to its beneficial use as an adsorbent for lead removal in water. This paper reviews on the sources, occurrences, and health effects of lead as well as the treatment of lead using HAp adsorbent for its removal in water. [ABSTRACT FROM AUTHOR]