Although microplastics (MPs) and nanoplastics (NPs) have become a global concern because of their possible hazards to marine organisms, few studies have investigated the effects of MPs/NPs on the ...nutritional quality of marine economic species, and the toxicity mechanisms remain unclear. We therefore investigated the effects of polystyrene MPs (PS-MPs, 5 μm) and NPs (PS-NPs, 100 nm) at an environmentally relevant concentration on adult scallops Chlamys farreri through the determination of nutritional composition, physiological metabolism, enzymatic response, and histopathology. Results showed that plastic particles significantly decreased the plumpness (by 33.32 % for PS-MPs and 36.69 % for PS-NPs) and protein content of the adductor muscle (by 4.88 % for PS-MPs and 8.77 % for PS-NPs) in scallops, with PS-NPs causing more notable impacts than PS-MPs. Based on the integrated biomarker response analysis, PS-NPs exhibited greater toxicity than PS-MPs, suggesting a size-dependent effect for plastic particle. Furthermore, PS-NPs significantly affected the physiological metabolism (e.g., filtration and ammonia excretion) than PS-MPs. Using gill transcriptomics analysis, the key toxicological mechanisms caused by NPs exposure included enrichment of the mitophagy pathway, responses to oxidative stress, and changes related to genes associated with nerves. This study provides new insights into the potential negative effects of MPs/NPs on the mariculture industry.
•Pt/RuO2/g-C3N4 photocatalyst was prepared for simultaneous removal of NH4+-N and bacteria in saline waters.•Pt and RuO2 facilitate the production of active chlorine without causing chlorine loss in ...saline waters.•The Pt/RuO2/g-C3N4 photocatalyst is effective in natural sunlight on actual water.
The removal of ammonia nitrogen (NH4+-N) and bacteria from aquaculture wastewater holds paramount ecological and production significance. In this study, Pt/RuO2/g-C3N4 photocatalysts were prepared by depositing Pt and RuO2 particles onto g-C3N4. The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–vis diffuse reflectance spectrometer (UV–vis DRS). The photocatalysts were then applied to the removal of both NH4+-N and bacteria from simulated mariculture wastewater. The results clarified that the removals of both NH4+-N and bacteria were in the sequence of g-C3N4 < RuO2/g-C3N4 < Pt/g-C3N4 < Pt/RuO2/g-C3N4. This magnificent photocatalytic ability of Pt/RuO2/g-C3N4 can be interpreted by the transfer of holes from g-C3N4 to RuO2 to facilitate the in situ generation of HClO from Cl− in wastewater, while Pt extracts photogenerated electrons for H2 formation to enhance the reaction. The removal of NH4+-N and disinfection effect were more pronounced in simulated seawater than in pure water. The removal efficiency of NH4+-N increases with an increase in pH of wastewater, while the bactericidal effect was more significant under a lower pH in a pH range of 6–9. In actual seawater aquaculture wastewater, Pt/RuO2/g-C3N4 still exhibits effective removal efficiency of NH4+-N and bactericidal performance under sunlight. This study provides an alternative avenue for removement of NH4+-N and bacteria from saline waters under sunlight.
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•The SMX degradation efficiency reached to 73.5%, and the toxic impacts was reduced.•The algal cell density was improved by 72.8% under SMX stress.•The interact between algae and ...bacteria enhanced biodegradation and tolerance to antibiotics.•Transcriptome disclosed upregulation of photosynthesis-related genes in microalgae.•Metagenomic revealed the adaptability of microbial community to antibiotic stress.
Acidogenic fermentation coupled with microalgae cultivation is cost-effective for treating mariculture wastewater (MW), however the molecular responses of fermentative bacteria and microalgae to antibiotic in MW at the metagenomic and transcriptome levels remain unclear. In this study, the degradation process of sulfamethoxazole (SMX) and its effects on microbial metabolism pathways were investigated in a bacterial-algal coupling reactor (BACR). The SMX degradation efficiency reached to 73.5%, and the toxic impacts was reduced. The algal cell density analyzed with flow cytometer was improved by 72.8% under SMX stress. Higher superoxide dismutase activity and the accumulation of carbohydrate (40.2%), protein (36.8%), lipid (33.7%) reflected the intracellular responses of microalgae. Transcriptome analysis disclosed upregulation of photosynthesis, electron transport, ATP and DNA synthesis in response to SMX, thus promoting microalgae biomass accumulation. In fermentation unit, Proteobacteria and Bacteroidota as dominant functional microorganisms were enriched. Metagenomic analysis revealed that the abundance of carbon metabolism pathways and two-component signal transduction pathways increased by 32.3% and 82.9%, thus improved the adaptability of microbial community to antibiotic stress. The establishment of the fermentative bacteria and microalgae coupling system enhanced the biodegradability and promoted the tolerance to antibiotics stress.
Macroalgae are being consumed by a growing number of people as functional food. Therefore, they are intensively cultivated to meet the rising demand. Mariculture is a potential source of ...microplastics (MPs). However, as a potential source of microplastics, little is known regarding the MPs pollution in macroalgae of open sea macriculture. Here we investigated the MPs characteristics in macroalgae in three sections of Haizhou Bay, an important mariculture area in China, during Pyropia culture (Pyropia yezoensis) and non-culture periods (Ulva prolifera, Sargassum horneri, Cladophora sp., Undaria pinnatifida, Ulva pertusa). It was found that P. yezoensis during the culture period had higher MPs abundance (0.17 ± 0.08 particles g−1fresh weight) than other macroalgae (0.12 ± 0.09 particles g−1 fresh weight) during the non-culture period, particularly for the nearshore sections. There were more fiber MPs in P. yezoensis (90.43%) in culture period compared to macroalgae (84.46%) in non-culture period. Highly similar spectrum of plastics in culture gears and macroalgae was verified. Pyropia culture gears released about 1, 037 tons plastics into the environment annually and the MPs abundances in seawater during the culture and non-culture periods were 1.04 ± 0.32 and 1.86 ± 0.49 particles L−1, respectively. The gap of MPs abundance between the two periods can be attributed to the tremendous trapping by massive biomass of P. yezoensis during the culture period and the continuous plastic release during the non-culture period. This study indicates that culture gears of macroalgae could be an important MPs source and the MPs can be transferred to human by edible macroalgae, and meanwhile macroalgae may be ideal biomonitors for MPs pollution in seawater due to their unbiased trapping and immovability.
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•Mariculture releases a large amount of plastics into the environment annually.•Macroalgae can accumulate microplastics via diverse mechanisms.•Mariculture exacerbates microplastics pollution in macroalgae.•Macroalgae can be ideal bioindicators for microplastics pollution.
The green development of the mariculture industry involves the interaction of economic, resource, environmental and scientific systems, and is a complex and dynamic process. To investigate the effect ...of different policies on this process, this paper used the system dynamics method to construct a simulation model of the green development of China's mariculture industry, simulating the green development trend of the mariculture industry from 2021 to 2035, and on this basis, four policy simulation models were set up for comparative analysis, with economic input, ecological protection and scientific and technological innovation as the guide. The results showed that under the status quo development model, the overall level of green development of mariculture had improved, but the pressure of resource consumption and environmental pollution had increased, and economic growth was weak. Under a single regulatory policy scenario, economic development policies could hardly achieve green development, science and technol
Microplastics are ubiquitous in the aquatic environment. However, the occurrence of microplastics in farmed fish is under-researched. Herein, microplastic abundance in the stomach and intestine of ...marine-cultured hybrid groupers (Epinephelus fuscoguttatus × Epinephelus lanceolatus) in the Pearl River Estuary (PRE) was examined. Microplastics were detected in all fish samples, with an average abundance of 35.36 n/individual or 0.62 n/g. The fish intestine contained more microplastics (23.91 n/individual, i.e., 1.10 n/g) than the stomach (12.80 n/individual, i.e., 0.37 n/g). In addition, the ingested microplastics were predominantly fibre-shaped (70.1%), and nearly 70% were smaller than 1 mm in diameter. Potential factors affecting the ingestion of microplastics by farmed hybrid groupers include fish diet and the availability of microplastics in their feeding habitat.
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•Microplastics occurred in all farmed hybrid groupers from the Pearl River Estuary.•Microplastics were more abundant in the intestine than in the stomach.•Fibres accounted for 70.1% of the detected microplastics.•Microplastics smaller than 1 mm represented 68.6% of the total count.•Potential factors causing microplastic ingestion by farmed fish were discussed.
First detection of Koi herpesvirus disease Akbar Hasan Al-Jaf, Diyar; Nawokas, Shaymaa Abdulaziz; Mardoukhi, Muhammad Majed
PloS one,
05/2024, Volume:
19, Issue:
5
Journal Article
Peer reviewed
Koi herpesvirus disease (KHVD) is attributed to cyprinid herpesvirus-3 (CyHV-3) and predominantly affects common carp and ornamental koi carp (Cyprinus carpio). This viral infection leads to ...substantial morbidity and mortality among these fish species. This study aimed to confirm the presence of KHVD in the Kurdistan region of Iraq by employing clinical and optimized molecular assays on fish populations experiencing high mortality among common carp in carp farms. The present research was conducted in the Kalar district, situated at the heart of Garmian province in Iraqi Kurdistan. four samples from common carp fish farms were received by our laboratory. These samples specifically displaying clinical signs associated with koi herpesvirus (KHV) infection, were subjected to clinical examinations, and PCR assay in addition to sequence analysis. The results of the current study revealed that the observed clinical signs, particularly gill necrosis, skin lesions, and sunken eyes, closely resembled the clinical signs of KHVD in common carp fish. In addition, PCR, nested PCR, and sequence analysis assay detected appropriate DNA fragments of the CyHV-3 major capsid protein gene confirming the first detection of KHVD in common carp fish in the Kurdistan region of Iraq. In this study, the results confirm the detection of KHVD in the Kurdistan region, Iraq, for the first time. This study revealed that CyHV-3 was responsible for KHVD-related signs and symptoms. Based on these results, it is strongly recommended that comprehensive studies be initiated to investigate the prevalence and distribution of CyHV-3.
The abuse of antibiotics has caused the propagation of antibiotic resistance genes (ARGs) in aquaculture systems. Although the recirculating systems have been considered as a promising approach for ...preventing the coastal water pollution of antibiotics and ARG, rare information is available on the distribution and proliferation of ARGs in the recirculating mariculture system. This study firstly investigated the proliferation of ARGs in coastal recirculating mariculture systems. Ten subtypes of ARGs including tet (tetB, tetG, tetX), sul (sul1, sul2), qnr (qnrA, qnrB, qnrS), and erm (ermF, ermT) were detected. The absolute abundances of the ARGs detected in the mariculture farm were more than 1 × 104 copies/mL. The sulfonamide resistance genes (sul1 and sul2) were the most abundant ARGs with the abundance of 3.5 × 107–6.5 × 1010 copies/mL. No obvious correlation existed between the antibiotics and ARGs. Some bacteria were positively correlated with two or more ARGs to indicate the occurrence of multidrug resistance. The fluidized-bed biofilter for wastewater treatment in the recirculating system was the main breeding ground for ARGs while the UV sterilization process could reduce the ARGs. The highest flux of ARGs (6.5 × 1021 copies/d) indicated that the discharge of feces and residual baits was the main gateway for ARGs in the recirculating mariculture system to enter the environments.
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•Proliferation of ARGs in coastal recirculating mariculture system was investigated.•The sul1 and sul2 were the most abundant with abundance of 3.5 × 107–6.5 × 1010 copies/mL.•Bacteria correlated with more than one ARGs possessed multidrug-resistant potential.•The biochemical pool for wastewater treatment was the main breeding ground for ARGs.•The discharge of feces and residual baits was the main discharge gateway for ARGs.
The investigation demonstrated that ARGs in the recirculating mariculture system were mainly discharged through the disposal of feces and residual baits.
Contamination characteristics, equilibrium partitioning and risk assessment of phthalate esters (PAEs) were investigated in seawater, sediment and biological samples collected from the Xiangshan Bay ...area during an annual investigation between January and November 2019. PAE concentrations detected in the mariculture environment in surface seawater, sediment, and biological samples were 172–3365 ng/L, 190–2430 μg/kg (dry weight dw), and 820–4926 μg/kg (dw), respectively. The dominant congeners in different media included di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), and di(2-ethylhexyl) phthalate (DEHP). The inner bay and the bay mouth were the gathering area of PAEs and heavily influenced by the mariculture activities, river inputs, and anthropogenic activities. The bioaccumulation of PAEs demonstrated benthic feeding fishes with relatively high trophic levels concentrated high levels of phthalates. The mobility of PAEs in sediment–seawater showed that the transfer tendency of low-molecular weight species was from the sediment to the water, which was in contrast with those of high-molecular weight PAEs. DEHP, DiBP and DnBP had various degrees of ecological risks in the aquatic environment, whereas only the DiBP posed potential risks in sediments. The current assessment of carcinogenic and noncarcinogenic risks posed by fish consumption were within acceptable limits for humans.
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•DEHP, DnBP and DiBP were most abundant PAEs in all media.•The inner bay and the bay mouth were the gathering area of PAEs.•The transfer tendency of PAEs in sediment-water is concerned with their KOW.•HR and CR posed by the consumption of fish were within acceptable limits for humans.
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