Search Results (11)

Intensive aquaculture and animal farming along riverbanks have emerged as significant drivers of downstream public health risks, facilitating the transmission of zoonotic pathogens and antimicrobial resistance (AMR) genes from farm effluents into natural water systems. In this study, we conducted a comprehensive 12-week water monitoring program at the Wei River in Shandong, China, using a combination of rapid detection techniques (RPA-LFD) and whole-genome sequencing to trace the origins of detected pathogens. RPA-LFD screening revealed the sequential appearance of Vibrio parahaemolyticus, Aeromonas veronii, norovirus GII, and Brucella spp. in surface water from March onward, coinciding with documented wastewater discharge events from upstream shrimp and fox farms. Subsequent isolation efforts confirmed the presence of V. parahaemolyticus and A. veronii in both river water and shrimp samples, while Brucella abortus was isolated from fox feces and water samples. Whole-genome sequencing of bacterial isolates revealed that V. parahaemolyticus strains from water and shrimp shared identical sequence types (ST150 and ST809) and resistance gene profiles, indicating a clonal relationship. Similarly, B. abortus isolates from water and fox feces differed by fewer than five SNPs, confirming farm-to-water transmission. Norovirus GII.3 and GII.6 sequences from water and fecal samples clustered phylogenetically with regional clinical strains, suggesting local circulation and environmental dissemination. Our findings highlight the critical role of river water monitoring as an early warning system for pathogen spread, emphasizing the need for integrated surveillance systems that monitor both water quality and the health of upstream farms and wildlife populations. The combined use of RPA-LFD and whole-genome sequencing provides a robust framework for real-time detection and source tracing of zoonotic pathogens, offering valuable insights for future environmental monitoring and public health interventions. Full article

Global marine coastal aquaculture increased by 6.7 million tons in 2024, with whiteleg shrimp (Penaeus vannamei) dominating crustacean production. However, reliance on a single species raises sustainability concerns, particularly in the face of climate change. Diversifying shrimp farming by cultivating native species, such as the European brown shrimp (Crangon crangon), presents an opportunity to develop a sustainable blue bioeconomy in Europe. C. crangon holds significant commercial value, yet overexploitation has led to population declines. Integrated Multi-Trophic Aquaculture (IMTA) offers a viable solution by utilizing fish farm wastewater as a nutrient source, reducing both costs and environmental impact. Research efforts in Germany and other European nations are exploring IMTA’s potential by co-culturing shrimp with species like sea bream, sea bass, and salmon. The physiological adaptability and omnivorous diet of C. crangon further support its viability in aquaculture. However, critical knowledge gaps remain regarding its lipid metabolism, early ontogeny, and reproductive biology—factors essential for optimizing captive breeding. Future interdisciplinary research should refine larval culture techniques and develop sustainable co-culture models. Expanding C. crangon aquaculture aligns with the UN’s Sustainable Development Goals by enhancing food security, ecosystem resilience, and economic stability while reducing Europe’s reliance on seafood imports. Full article

The rapid expansion of shrimp aquaculture has led to the generation of nutrient-rich effluents, which contribute to environmental degradation if inadequately managed. This study evaluated the potential of Dunaliella salina for the reuse of shrimp aquaculture wastewater (SAW) in biofloc production systems under varying dilution levels (0%, 25%, and 50%) and the simultaneous production of high-value biomass. Growth kinetics were modeled using a four-parameter logistic model, and nutrient removal, biochemical composition, and fatty acid profile were assessed. D. salina exhibited substantial growth in undiluted SAW, achieving over 80% removal of total nitrogen and reducing the organic load, as measured by a chemical oxygen demand reduction of more than 79%. In SAW treatments, the protein content ranged from 24.7% to 26.3%, while the lipid content reached up to 67.1% in a 25% SAW dilution. Chlorophyll a and total carotenoids were measured at 5.3–7 µg/mL and 4.1–5.7 µg/mL, respectively, in SAW treatments. The polyunsaturated fatty acid content in undiluted SAW was 34.5%, with α-linolenic acid (C18:3n3) and linoleic acid (C18:2n6) comprising 12% and 7.5%, respectively. This study demonstrates the ability of D. salina to valorize shrimp aquaculture wastewater in biofloc systems into lipid-rich, bioactive biomass, supporting its use in integrated aquaculture biotechnology systems for sustainable wastewater management and bioproduct generation. Full article

As the scale of shrimp aquaculture continues to expand, the environmental impacts of shrimp effluents have become increasingly severe. The purification of aquaculture effluents can no longer be overlooked. Effectively reducing the discharge of aquaculture wastewater and mitigating its potential pollution risks to the surrounding aquatic ecological environment are key issues that need to be addressed to promote the industry’s development towards a greener, more environmentally friendly, and sustainable path. This study explored the purification effect of the integration of tilapia and Spirulina on tail water from a zero-water-exchange aquaculture of whiteleg shrimp (Litopenaeus vannamei) in seawater, with the aim of assessing the growth performance of tilapia and the efficacy of the fish–algae integration in purifying tail water from the perspective of tail water resource utilisation. The study found that the removal rates of the biofloc sedimentation volume and total suspended particle concentration in the fish–algae group were 42.6% and 29.6%, respectively. The removal rates of phosphate and total phosphorus in the fish–algae group were 26.3% and 20.8%, respectively. Research indicates that tilapia effectively removes suspended organic matter from water. Introducing Spirulina into this water body aids in the removal of soluble nitrogen and phosphorus from the effluent, and tilapia exhibit a favourable feeding response to Spirulina. Full article

The aquaculture industry requires green solutions to solve several environmental challenges, including adequate wastewater remediation and natural drug applications to treat bacteria- and virus-related diseases. This study investigated the feasibility of cultivating the dinoflagellate Durusdinium glynnii in aquaculture wastewater from shrimp rearing in a synbiotic system (AWW-SS), with different dilutions of f/2 medium (FM). Interestingly, D. glynnii demonstrated enhanced growth in all AWW–SS treatments compared to the control (FM). The highest growth rates were achieved at AWW-SS:FM dilutions of 75:25 and 50:50. The removal of total nitrogen and total phosphorus reached 50.1 and 71.7%, respectively, of the crude AWW–SS. Biomass extracts of D. glynnii grown with AWW–SS were able to inhibit the growth of the bacteria Vibrio parahaemolyticus (inhibition zone of 10.0 ± 1.7 mm) and V. vulnificus (inhibition zone of 11.7 ± 1.5 mm). The presented results demonstrate that the dinoflagellate D. glynnii is a potential candidate for the development of circularity for sustainable aquaculture production, particularly by producing anti–Vibrio compounds at a near-zero cost. Full article

The major sources of waste from aquaculture operations emanates from fish or shellfish processing and wastewater generation. A simple technique called coagulation/flocculation utilizes biowaste from aquaculture to produce chitosan coagulant for wastewater treatment. A chemical method was applied in the present study for chitin and chitosan extraction from carapace of Macrobrachium rosenbergii and subsequent application for removal of turbidity and salinity from shrimp aquaculture wastewater. Box-Behnken in RSM was used to determine the optimum operating conditions of chitosan dosage, pH, and settling time, after which quadratic models were developed and validated. Results show that 80 g of raw powder carapace yielded chitin and chitosan of 23.79% and 20.21%, respectively. The low moisture (0.38%) and ash (12.58%) content were an indication of good quality chitosan, while other properties such as water-binding capacity (WBC), fat-binding capacity (FBC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM) confirmed the structure and the α-group, as well as the rough morphology of chitosan. In addition, the high solubility (71.23%) and DDA (85.20%) suggested good coagulant potentials. It was recorded in this study that 87.67% turbidity was successfully removed at 20 mg/L of chitosan dosage and 6.25 pH after 30 min settling time, while 21.43% salinity was removed at 5 mg/L of chitosan dosage, 7.5 pH, and 30 min settling time. Therefore, the process conditions adopted in this study yielded chitosan of good quality, suitable as biopolymer coagulant for aquaculture wastewater treatment. Full article

The aquaculture industry in Taiwan grosses more than USD 1.1 billion annually; however, it also generates considerable waste discharge (causing eutrophication in estuarine and coastal waters) and heavy groundwater withdrawals (causing land subsidence in coastal areas). Many aquaculture facilities using earth ponds are affected by benthic algae, resulting in an earthy odor, and fixed-cage farms are difficult to relocate during cold weather events. In this study, we tested small-scale (~15 ton) mobile cage tanks for the nearshore rearing of white shrimp and grouper in the Yung-An district of Kaohsiung, Taiwan. At the conclusion of the mariculture experiment, the content of free amino acids in shrimp and groupers reared in our mobile tanks surpassed that in animals reared locally in traditional earthy ponds. In a blind taste test involving 42 volunteers, groupers reared in mobile cage tanks were deemed more palatable than those raised in ponds. Our results demonstrate that small-scale mobile cage tanks are a feasible approach to the sustainable rearing of high-quality shrimp or fish. Note that wastewater from the mobile tanks is easily diluted by seawater, thereby reducing the likelihood of eutrophication in coastal regions. The proposed system could also be used for recreational fishing activities to increase income for smallholders of fishermen and/or aquaculture farmers. Full article

Waterborne ammonia is becoming one of the most notorious pollutants in aquatic habitats and has been shown to induce a range of ecotoxicological effects on aquatic animals. High ammonia concentrations occur mainly in intensive aquaculture systems, and effective wastewater treatment and agricultural systems are necessary to treat excessive nitrogenous compounds. Ammonia can enter aquatic decapod crustaceans through their gills, thereby reducing the oxygen-carrying capacity of blood cells and damaging the structures of organs such as the gills and hepatopancreas. This ultimately results in oxidative stress, immunotoxicity, and high mortality. Crustaceans have the ability to exert detoxification functions against ammonia stress by regulating the permeation of ammonia and related nitrogenous compounds through membranes. To the best of our knowledge, a comprehensive review of the acute toxicity of ammonia to crustaceans is lacking. The present review focuses on the literature on the problems and mechanisms concerning ammonia-induced acute toxicity and aims to synthesize the knowledge of the relationship between ammonia stress and defense responses in crustaceans (mainly shrimp and crabs). This review also emphasizes the uptake, elimination, and detoxification of ammonia in crustaceans. Full article

The residues and abuse of antibiotics have seriously endangered ecological balance and human health; meanwhile, antibiotics determination is very difficult because of their low levels and multiple categories in complicated matrices. Appropriate sample pretreatment is usually imperative to enrich (ultra)trace antibiotics and eliminate matrix interference prior to chromatographic analysis. Dispersive liquid-liquid microextraction (DLLME) has become an ideal pretreatment technique owing to its simplicity, effectiveness, low-consumption, etc. In this work, an ultrasonic-assisted DLLME (UA-DLLME) was developed for the simultaneous extraction of seven sulfonamides (SAs) antibiotics in environmental water and seafood samples coupled with HPLC-DAD determination. Several parameters affecting UA-DLLME efficiency were systematically optimized, and consequently the SAs were separated and detected within 14.5 min. The obtained limits of detection (LODs) and limits of quantification (LOQs) ranged from 0.7–7.8 μg/L and 2.4–26.0 μg/L for three water samples (seawater, aquaculture wastewater and lake water) and two seafood samples (pomfrets and shrimps). High recoveries (80.0–116.0%) with low relative standard deviations (0.1–8.1%) were achieved for all the tested samples at three spiked levels. Notably, sulfadimethoxine was found at 24.49 μg/L in one seawater sample. The facile, robust and benign DLLME-HPLC method demonstrated promising perspectives for multiresidue analysis of antibiotics. Full article

Biological settling ponds are a practicable approach for treating super-intensive shrimp aquaculture wastewater for almost all shrimp producers in the Vietnamese Mekong Delta (VMD). The optimization of the hydraulic retention time (HRT) of biological settling ponds plays a crucial role in establishing the stability of outflow wastewater quality and suitability of the settling pond area (SPA). This study aims to suggest appropriate HRT and SPA for super-intensive shrimp wastewater treatment systems based on the National Standard (QCVN 02-19:2014/BNNPTNT) and the best aquaculture practices (BAP) standards and guidelines. We investigated 20 typical super-intensive shrimp farms in the VMD and collected effluent samples from siphoning process, daily water exchange, and outflow of biological effluent-treatment settling ponds. The results showed that the average of each super-intensive shrimp farm produced wastewater at approximately 218 m³ ha⁻¹ day⁻¹. The contaminant loads of TSS, COD, TKN, and TP were commensurate to 177, 113, 9.86, and 4.19 kg ha⁻¹ day⁻¹, respectively. Based on the relationship between outflow COD, TSS concentrations, and HRT of biological-surveyed settling ponds, a 13.4-day HRT and 1934-m² SPA were suggested to optimize the super-intensive shrimp wastewater treatment systems. Our recommendation for further work is to continuously optimize the HRT and SPA rates of functional ponds (anaerobic, facultative, and maturation) to ameliorate the engineering configuration of the recommended biological settling pond. Full article

Microalgae are promising feedstock for the production of biodiesel and diverse medium- and high-value products such as pigments and polyunsaturated fatty acids. The importance of strain selection adapted to specific environments is important for economical purposes. We characterize here two microalgal strains, isolated from wastewater of shrimp cultivation ponds in Vietnam. Based on the 18S rDNA-ITS region, one strain belongs to the Eustigmatophyceae class and is identical to the Nannochloropsis salina isolate D12 (JX185299.1), while the other is a Chlorophyceae belonging to the Desmodesmus genus, which possesses a S516 group I intron in its 18S rDNA gene. The N. salina strain is a marine and oleaginous microalga (40% of dry weight (DW) at stationary phase) whole oil is rich in saturated fatty acids (around 45% of C16:0) suitable for biodiesel and contains a few percent of eicosapentaenoic acid (C20:5). The Desmodesmus isolate can assimilate acetate and ammonium and is rich in lutein. Its oil contains around 40%–50% α-linolenic acid (C18:3), an essential fatty acid. Since they tolerate various salinities (10% to 35‰), both strains are thus interesting for biodiesel or aquaculture valorization in coastal and tropical climate where water, nutrient, and salinity availability vary greatly depending on the season. Full article