Evaluation and Analysis of Water Quality of Marine Aquaculture Area

Pattern of color inheritance in African catfish (Clarias gariepinus): an expression of a Mendelian law

In this study the pattern of color of inheritance based on Mendel's laws on the Clarias gariepinus strain was evaluated, to ascertain the different traits of albino, normally pigmented, and a combination of both traits that could be passed across from the parent stocks to the progenies. Since albinism is caused by a series of genetic abnormalities resulting in the reduction of melanin production, partial diallel cross between normally pigmented and albino fish was carried out using two females (albino and normal pigmented brood fish) weighing 2.5 kg and 3 kg, respectively; they were used in crossing two males (albino and normal pigmented brood fish) that weighed 1.5 kg and 1 kg, respectively. They were paired with normal pigmented (♂Np × ♀Np) and albino C. gariepinus (♂Ae × ♀Ae) fish to produce a pure strain of normally pigmented and albino strain, respectively. To produce the hybrids, they were paired (♂Np × ♀Ae) and (♂Ae × ♀Np), respectively. The outcomes of this study showed that crossbreeding between normally pigmented females and albino males produced all normally pigmented F1 generation, while some quantity of albino (36.67%) at crossing male albino to normally pigmented females were produced. However, the pure strains breed true (100%). Each hybrid exhibits heterosis after 56 days of rearing compared to the normal strain that was crossed, although the normally pigmented fish gives a better SGR. Hence, there is a need to investigate if sex is linked with albinism.

Establishment and characterization of Yellow River carp (Cyprinus carpio haematopterus) muscle cell line and its application to fish virology and immunology

The Yellow River carp (Cyprinus carpio haematopterus) is a vital economically farmed fish of the Cyprinidae family. With the development of intensive aquaculture, carp production has increased dramatically, leading to the frequent occurrence of various diseases. Cell lines are considered the most cost-effective resource for in vitro studies and are widely used for physiological and pathological studies because of accessibility and convenience. This research established a novel immortal cell line CCM (Yellow River carp muscle cells) derived from the carp muscle. CCM has been passed over 71 generations for 1 year. The morphology of CCM and the adhesion and extension processes were captured by light and electron microscopy. CCM were passaged every 3 days with 20% FBS DMEM/F12 at 1:3. The optimum conditions for CCM growth were 28 °C and 20% FBS concentration. DNA sequencing of 16S rRNA and COI showed that CCM was derived from carp. CCM positively reacts to anti-PAX7 and anti-MyoD antibodies of carp. Analysis of chromosomes revealed that the chromosomal pattern number of CCM was 100. Transfection experiment demonstrated that CCM might be utilized to express foreign genes. Furthermore, cytotoxicity testing showed that CCM was susceptible to Aeromonas hydrophila, Aeromonas salmonicida, Aeromonas veronii, and Staphylococcus Aureus. The organophosphate pesticides (chlorpyrifos and glyphosate) or heavy metals (Hg, Cd, and Cu) exhibited dose-dependent cytotoxicity against CCM. After LPS treatment, the MyD88-IRAKs-NFκB pathway stimulates inflammatory-related factor il1β, il8, il10, and nfκb expression. LPS did not seem to cause oxidative stress in CCM, and the expression of cat and sod was not affected. Poly (I:C) through TLR3-TRIF-MyD88-TRAF6-NFκB and TRIF-TRAF3-TBK1-IRF3 activated the transcription of related factors, increased expression of anti-viral protein, but no changes in apoptosis-related genes. To our knowledge, this is the first muscle cell line in Yellow River carp and the first study on the immune response signal pathways of Yellow River carp based on the muscle cell line. CCM cell line provides a more rapid and efficient experimental material for fish immunology research, and this study preliminarily elucidated its immune response strategy to LPS and poly (I:C).

Morphologic and genic effects of waste pollution on the reproductive physiology of Paracentrotus lividus lmk: a mesocosm experiment

A considerable amount of coastal contamination is caused by wastes deriving from household and the degradation and the metabolism of plants and animals, even if our attention is commonly focused on industrial pollutants and contaminants. Waste pollutants are mainly represented by highly diluted soluble compounds and particles deriving from dead organisms. This complex combination, consisting of suspended particles and dissolved nutrients, has a significant impact on coastal planktonic and benthic organisms, also playing an active role in the global cycles of carbon. In addition, production practices are nowadays shifting towards recirculated aquaculture systems (RAS) and the genic responses of target organisms to the pollution deriving from animal metabolism are still scarcely addressed by scientific investigations. The reservoir of organic matter dissolved in the seawater is by far the least understood if compared to that on land, cause only a few compounds have been identified and their impacts on animals and plants are poorly understood. The tendency of these compounds to concentrate at interfaces facilitates the absorption of dissolved organic compound (DOC) onto suspended particles. Some DOC components are chemically combined with dissolved metals and form complexes, affecting the chemical properties of the seawater and the life of the coastal biota. In this research, we compared the reproductive performances of the common sea urchin Paracentrotus lividus cultured in open-cycle tanks to those cultured in a recirculating aquaculture system (RAS), where pollution progressively increased during the experiment due to animal escretions. Sea urchins were cultured for 7 months under these two conditions and their gametes were collected. Embryos resulting by in vitro fertilization were analyzed by Real Time qPCR to identify possible effects of pollution-induced stress. The fertility of sea urchins was evaluated, as well as the gonadosomatic indices and the histological features of gonads. Our results indicate that pollution due to excess of nutrients, event at sub-lethal concentrations, may hardly impact the reproductive potential of this key species and that chronic effects of stress are revealed by the analyses of survival rates and gene expression.

Historical biomonitoring of pollution trends in the North Pacific using archived samples from the Continuous Plankton Recorder Survey

First started in 1931, the Continuous Plankton Recorder (CPR) Survey is the longest-running and most geographically extensive marine plankton sampling program in the world. This pilot study investigates the feasibility of biomonitoring the spatiotemporal trends of marine pollution using archived CPR samples from the North Pacific. We selected specimens collected from three different locations (British Columbia Shelf, Northern Gulf of Alaska, and Aleutian Shelf) in the North Pacific between 2002 and 2020. Comprehensive profiling of the plankton chemical exposome was conducted using liquid and gas chromatography coupled with tandem mass spectrometry (LC-MS/MS and GC-MS/MS). Our results show that phthalates, plasticizers, persistent organic pollutants (POPs), pesticides, pharmaceuticals, and personal care products were present in the plankton exposome, and that many of these pollutants have decreased in amount over the last two decades, which was most pronounced for tri-n-butyl phosphate. In addition, the plankton exposome differed significantly by regional human activities, with the most polluted samples coming from the nearshore area. Exposome-wide association analysis revealed that bioaccumulation of environmental pollutants was highly correlated with the biomass of different plankton taxa. Overall, this study demonstrates that exposomic analysis of archived samples from the CPR Survey is effective for long-term biomonitoring of the spatial and temporal trends of environmental pollutants in the marine environment.

Photodegradation of Ciprofloxacin and Levofloxacin by Au@ZnONPs-MoS2-rGO Nanocomposites

This study aimed to investigate the photocatalytic performance of diverse zinc oxide catalysts containing gold nanoparticles (AuNPs), molybdenum disulfide (MoS2), and reduced graphene oxide (rGO) toward the degradation of the antibiotics levofloxacin (LFX) and ciprofloxacin (CFX) in aqueous solutions. The obtained results demonstrate that LFX is more resistant to degradation when compared with CFX and that the principal route of degradation under visible light is the formation of hydroxyl radicals. Photoluminescence (PL) measurements were employed to verify the inhibitory effect of electron–hole recombination when AuNPs, MoS2, and rGO are integrated into a semiconductor. The catalyst that achieved the highest percentage of CFX degradation was 1%Au@ZnONPs-3%MoS2-1%rGO, exhibiting a degradation efficiency of 96%, while the catalyst that exhibited the highest percentage of LFX degradation was 5%Au@ZnONPs-3%MoS2-1%rGO, displaying a degradation efficiency of 99.8%. A gas chromatography–mass spectrometry (GC-MS) analysis enabled the identification of reaction intermediates, facilitating the determination of a potential degradation pathway for both antibiotics. Additionally, recyclability assessments showed that the synthesized catalysts maintained stable photocatalytic efficiencies after 15 cycles, indicating that the heterostructures have the potential for further usage and may be tested with other organic contaminants as well.

Evaluation of heavy metal contamination in the coastal aquaculture zone of the Red River Delta (Vietnam)

Coastal aquaculture contributes significantly to the local economy of many countries however water quality issues in the coastal regions are threatening the sustainability of this economic activity. This paper presents the analysis of seven heavy metals (HM) in surface seawater and wastewater from the Red River coastal aquaculture zone during 2019-2020. HM concentrations (μg.L^-1) from 72 seawater samples were: Zn: 60.76 (0.5-188.0); Cu: 26.91 (0.10-96.0); Pb: 7.27 (0.8-31.2); Cr: 6.71 (0.6-28.4); As: 1.38 (0.15-5.78); Cd: 0.44 (0.04-2.41); and Hg: 0.34 (0.02-1.39). All mean values of HM in seawater were lower than the Vietnam regulatory limits for aquaculture seawater although high individual HM concentrations were found in some isolated seawater samples. Concerning wastewater quality, only mean As concentration was higher than the Vietnam regulatory limit for surface water quality, despite the fact that high concentrations of other individual HM were observed. The PCA analysis on the entire dataset of seawater and wastewater samples revealed that HM concentrations in seawater originate from various sources including human activities and natural conditions. The total potential ecological risk index (averaging 18.6; from 7.48 to 39.05) for the Red River coastal zone is in the low range. These results provide a scientific basis for better management of the coastal environment which is important for the sustainable development of the aquaculture industry in this area.

On-Farm Practices Associated with Multi-Drug-Resistant Escherichia coli and Vibrio parahaemolyticus Derived from Cultured Fish

Aquaculture activities have been implicated as responsible for the emergence of antimicrobial resistance (AMR), leading to broad dissemination and transference of antibiotic resistance to pathogens that affect humans and animals. The current study investigates the on-farm practices and environmental risk factors that can potentially drive the development and emergence of multi-drug-resistant (MDR) Escherichia coli and Vibrio parahaemolyticus in the aquaculture system. A cross-sectional study was conducted on 19 red hybrid tilapia (Oreochromis spp.) and 13 Asian seabass (Lates calcarifer, Bloch 1970) farms on the west coast of peninsular Malaysia. Data were collected using a structured questionnaire pertaining to farm demography, on-farm management practices and environmental characteristics. Multi-drug-resistant E. coli (n = 249) and V. parahaemolyticus (n = 162) isolates were analyzed using multi-level binary logistic regression to identify important drivers for the occurrence and proliferation of the MDR bacteria. On-farm practices such as manuring the pond (OR = 4.5; 95% CI = 1.21–16.57) were significantly associated with the occurrence of MDR E. coli, while earthen ponds (OR = 8.2; 95% CI = 1.47–45.2) and human activity adjacent to the farm (OR = 4.6; 95% CI = 0.75–27.98) were associated with an increased likelihood of MDR V. parahaemolyticus. Considering the paucity of information on the drivers of AMR in the aquaculture production in this region, these findings indicate the targeted interventions implementable at aquaculture farms to efficiently abate the risk of MDR amongst bacteria that affect fish that are of public health importance.

The dynamic of the potential pathogenic bacteria, antibiotic-resistant bacteria, and antibiotic resistance genes in the water at different growth stages of grass carp pond

Pond aquaculture has become the most important and broadest breeding model in China, and an extremely important source of aquatic products, but the potential hazard factors of potential pathogenic bacteria (PPB), antibiotic resistance bacteria (ARB), and antibiotic resistance genes (ARGs) in aquaculture environment are largely invisible. In the present study, the bacterial communities in the larvae, juvenile, rearing, and harvesting culture stages of great grass carp (Ctenopharyngodon idellus) ponds were investigated and the structure of microbial flora analysis showed that the larvae culture stage has the highest abundance and the most dominant phyla were Proteobacteria (27.8%). A total of 123 significant Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotations and the relative abundance of nine bacterial phenotypes implied that the larvae culture stage had the most abundance of pathogenic potential and mobile elements. The correlation analyses of environmental factors showed that temperature, stocking density, pH, and transparency showed the significant impacts on both the distribution of microbiome and the PPB. More importantly, a total of 40 ARB were identified, and 16 ARGs have the detection rates of 100%, which revealed that they are widely distributed and highly enriched in the aquaculture production. Notably, this is the first robust report to analyze and understand the PPB, ARB, and ARGs characteristics and dynamic changes in the pond aquaculture.

Influence of probiotics on water quality in intensified Litopenaeus vannamei ponds under minimum-water exchange

The effects of two probiotics on NH₃ degradation, as well as the magnetic field (21.56 m tesla) on the germination and proliferation of Bacillus spores, were studied in-vitro. Additionally, the effect of these probiotics on water quality maintenance in Litopenaeus vannamei holding ponds was investigated. For 180 min, NH₃ degradation was assessed as follows: Set 1: ammonia-free tap water with NH₃; Probiotic A (5 × 10¹⁰ viable Bacillus spores/g) with NH₃; Probiotic B (multi spp. 2 × 10⁹ CFU/g) with NH₃; and Set 2: same as set 1 with 30 mg L⁻¹ OM. The magnetic field was tested on Probiotic A (3.5 × 10⁷ CFU) for 36 h in triplicate. In the presence of organic matter, both probiotics degrade NH₃. The viable Bacillus count increased within 6 h of being exposed to the magnetic field, reaching its peak after 36 h. Firstly, fifteen ponds (250,000 PL/acre) were investigated, then 360 water samples were collected from the same corresponding pond for 8 weeks, and subjected to T1: control; T2: Probiotic A (0.007 g/m³/2 weeks); T3: Probiotic B (0.03 g/m³/2 weeks). Both probiotics with TVC and NH₃ demonstrated a negative correlation, on the other hand, they showed a significant (P ≤ 0.01) improvement in DO and pH. Overall, both probiotics were able to degrade NH₃ and the magnetic field (21.56 m tesla) was efficient to improve the germination and proliferation of Bacillus spores in-vitro. Probiotics were also effective for reducing TVC and NH₃ levels by increasing dissolved oxygen and pH in pond water.

Growth of marine diatoms on aquaculture wastewater supplemented with nanosilica

The aquaculture industry is a significant producer of highly nutritious food for the increasing global population. However, the wastewater generated from aquaculture ponds is an emerging global issue. The present study demonstrates the culturing of marine diatoms (Chaetoceros gracilis and Thalassiosira weissflogii) in different proportions of aquaculture wastewater (AQW) coupled with inductively coupled plasma nanosilica (ICP-SiO₂) and further explores their biorefinery potential concomitant nutrient removal. Thalassiosira weissflogii showed maximum carbohydrate content (79.47 ± 0.21 mg g^-1) in 10% and protein content (27.09 ± 0.21 mg g^-1) in 30% AQW: ICP-SiO₂. Chaetoceros gracilis showed maximum carbohydrate content (91.64 ± 0.11 mg g^-1) in 50% and protein content (27.75 ± 0.05 mg g^-1) in 10% AQW: ICP-SiO₂ respectively. Additionally, Chaetoceros gracilis showed maximum nitrate uptake in 30%, phosphate in 50%, and ammonia in 50% AQW: ICP-SiO_2. While Thalassiosira weissflogii showed maximum nitrate, phosphate, and ammonia removal efficiency in 50%, 50%, and 10% AQW: ICP-SiO₂ respectively. The study draws attention towards the utilization of diatoms in AQW treatment, aquafeed potential thus imparting a global circular bioeconomy.

Evaluation of Aquaculture Water Quality Based on Improved Fuzzy Comprehensive Evaluation Method

The quality of aquaculture waters is directly related to water management and aquaculture efficiency, which puts forward higher requirements for water quality evaluation. Based on the consideration of the influence of temporal and spatial changes on the water quality, this paper proposed an improved fuzzy comprehensive evaluation method for aquaculture water quality evaluation. Specifically, constructing a new membership function in the first place, and then selecting dissolved oxygen, pH, temperature and ammonia nitrogen content as water quality indexes for aquaculture, after that, collecting 60 sets of water quality index for different seasons in the past three years, finally, evaluating the water quality of Yangjiabo Aquaculture Base. Meanwhile, comparing it with the evaluation results of the single factor evaluation method and the traditional fuzzy evaluation method. The results show that the water quality of the Yangjiabo Aquaculture Base is at the worst level in winter, and the water quality has improved significantly in spring, summer and autumn. Compared with the other two method, the improved method can comprehensively reflect the changes in water quality with time and space, which is more practical, and so it can be considered to provide a scientific basis for efficient aquaculture and water quality classification.