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A large number of antibiotic residues are discharged into aquatic environments due to the widespread use of antibiotics in daily life. After a series of processes in the water, the residues will potentially have adverse impacts on water ecosystem and human health. Therefore, it is critical for mediating the pollution to know how the antibiotics transport and distribute in the water. This study utilizes a two-dimensional lattice Boltzmann model to find out the transport and distribution of antibiotics in a highly polluted area, the Laizhou Bay in China. Furthermore, the model was used to simulate two scenarios in the Laizhou Bay, the antibiotics from sewage treatment plants and the contamination of mariculture. The simulated results show that the model as an effective tool can provide a useful basis for the management of antibiotics-related environmental issues in the Laizhou Bay. [ABSTRACT FROM AUTHOR]

Ecological water replenishment is an effective approach to the wetlands suffering water shortage. However, optimizing the replenishment is a tough problem, considering local flow pattern, water exchange and environmental crisis. Therefore, determining the inlet position and the flow rate of water diversion remains an interesting and important topic. This study developed an applicable and reliable method to identify the preferable inlet location and inflow rates of the transferred water, which considers the influence of the factors on environmental risks in receiving water bodies based on numerical results using the lattice Boltzmann method (LBM) in both Lagrangian and Eulerian frameworks. An environmental risk assessment system with comprehensive utilization of water age was established. The Water Transfer Project for the Baiyangdian Lake from the Yellow River is a representative and well-known water replenishment event in China, which served as a case study. The results show that under the static and NNE wind conditions, the north open inlet is a suitable inlet position, while the south one is preferable under the SSW wind condition. Considering the environmental risk of the water transfer, it indicates that higher inflow rate would bring less environmental risk generally and the optimal inflow rate is 20 m 3 / s , regardless of the wind conditions and the inlet position. The methods aforementioned played a vital role in optimizing the inlet position of water delivery and selecting the optimal plan of the recharge rate. It could provide a useful reference for ecological restoration and a guarantee for sustainable development of wetlands. [ABSTRACT FROM AUTHOR]

Antibiotics are extensively applied in aquaculture for the treatment of microbial infections and to improve production. Among various antibiotics, sulfonamides (SA) are popular in fish farming, and SA residues in the aquatic environment have detrimental effects on both ecosystem and human health. Understanding the fate of SA in the aquatic environment is a basic necessity to provide an approach for solving the current problem. In this study, a two-dimensional lattice Boltzmann model was introduced to investigate the transport and occurrence of SA in Laizhou Bay, a prosperous aquaculture area in China. The model is based on the shallow-water equations and advection-diffusion equation with the Bhatnagaar–Gross–Krook scheme. Experimental data are used to verify the model after numerical simulations and the results illustrate the accuracy of the proposed model. This model provides a potential universal method for the simulation of the fate of antibiotics in the aquatic environment. [ABSTRACT FROM AUTHOR]

• We developed a marine ecosystem model for trade-offs between fishing and enhancement stocking. • The impact of fishing effort on the marine ecosystem was not well compensated by release of a single target species. • We designed an orthogonal experiment with three factors (key species) and four restocking release levels to determine the optimal release rate. • We optimized the key species release and fishing strategy to improve the marine biomass, trophic level, and biodiversity. The implementation of marine ecosystem management requires modeling that accounts for the trade-off between exploitation in fisheries and protection activities (e.g., enhancement and release, artificial reefs). Researchers are increasingly interested in the trends of fishery resources under these joint driving forces due to the negative impacts of resource exploitation and the positive impacts of marine protection. Using the sea around Juehua Island in China's Bohai Sea as a case study, we developed a marine ecosystem model based on the Ecopath with Ecosim software to analyze the trends in fishery resources driven both by fishing and stock enhancement. When the fishing effort exceeded 42 % of the 2019 value, the biomass of top predator Platycephalus indicus decreased by 50 %, indicating a regime shift. When the fishing effort increased to 340 % of the 2019 level, the ecosystem shifts to an alternative stable state occurs, indicating destabilization of the marine ecosystem. The impact of fishing effort on the marine ecosystem was not well compensated by release of a single target species. We also designed an orthogonal experiment with three factors (the key species Fenneropenaeus chinensis , Paralichthys olivaceus , and Charybdis japonica) and four restocking release levels to determine both the optimal release rate for each species individually and the optimal combination of different species. If the 2019 fishing effort is maintained, the release of 125 × 106 juvenile F. chinensis , 400 × 103 juvenile P. olivaceus , and 15 × 106 juvenile C. japonica would be an optimal solution to improve the marine biomass, trophic level, and biodiversity. Our results provide insights into ecosystem-based management strategies for implementing a policy to limit fishing in the study area and for scientifically determining the restocking release rates. [ABSTRACT FROM AUTHOR]

A Gram stain-positive, non-spore-forming, non-motile, short-rod actinomyces strain GXQ1321 T was isolated from maritime surface sediments in Beihai (21° 41' 21.65″ N, 109° 05' 76.56″ E), Guangxi Zhuang Autonomous Region, and a number of categorization studies were performed. Following a period of 72 h of incubation at a temperature of 30 °C within a modified actinomycete culture medium, the colony was light-yellow, circular, smooth, central bulge, convex, opaque, with a 1.2-2.3 mm diameter. Strain GXQ1321 T had the ability to degrade cellulose. Chemotaxonomic studies revealed that the major methylnaphthoquinones in strain GXQ1321 T was MK-8(H 2 ). The most prevalent cellular fatty acids were anteiso-C 19:0 , anteiso-C 15:0 , anteiso-C 17:0 , and iso-C 16:0 . The whole-cell sugars of the strain GXQ1321 T were identified rhamnose, xylose and glucose. Meso-diaminopimelic acid was found in the peptidoglycan hydrolysate, and the polar lipids were identified as diphosphatidylglycerol, three phosphoglycolipid, phosphatidylglycerol and two unknown glycolipid. This strain had 69.6% DNA G+C content. Strain GXQ1321 T is classified as Brevibacterium based on its 16S rRNA gene sequence. It is closely related to Brevibacterium samyangense SST-8  T (96.8%) and Brevibacterium rongguiense 5221  T (96.3%). The average nucleotide identity (ANI) values of GXQ1321 T and the above two type strains were 73.9-77.1%, and the digital DNA-DNA hybridisation (dDDH) values were 15.3-21.1%. Based on the phylogenetic, chemotaxonomic and physiological data, strain GXQ1321 T was considered to be a novel species of the genus Brevibacterium, named Brevibacterium litoralis sp. nov, with the type strain GXQ1321 T (= MCCC 1K08964 T  = KCTC 59167  T )., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

A novel gram-stain-positive, short rod, aerobic, non-motile and non-spore-forming actinobacterial strain, designated GXG1230 T was isolated from the rhizosphere soil of a coastal mangrove forest in Beihai city, Guangxi Zhuang Autonomous Region, PR China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain GXG1230 T was affiliated with the genus Microbacterium. Additionally, it demonstrated a high degree of similarity to Microbacterium paludicola US15 T (97.9%) and Microbacterium marinilacus YM11-607 T (97.3%). Chemotaxonomic characteristics showed that the whole-cell sugars were glucose, xylose, rhamnose and galactose. Menaquinones MK-11 and MK-12 were detected as respiratory quinones. Lysine was found in the peptidoglycan hydrolysate and the polar lipids were diphosphatidylglycerol, one phospholipid and two unidentified glycolipid. The major fatty acids were anteiso-C 15:0 , iso-C 16:0 and anteiso-C 17:0 . The strain GXG1230 T exhibited a genomic DNA G + C content of 71.7%. Furthermore, the average nucleotide identity values of GXG1230 T with the reference strains were 75.4% and 81.9%, respectively, while the digital DNA-DNA hybridization values were 20.1% and 25.0%. Based on physiological, chemotaxonomic and phylogenetic information, strain GXG1230 T is considered to represent a novel species of the genus Microbacterium, for which the name Microbacterium rhizophilus sp.nov is proposed, with GXG1230 T (= MCCC 1K09302 T  = KCTC 59252 T ) as the type strain., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Nutrient loads in lakes are spatially heterogeneous, but current spatial analysis method are mainly zonal, making them subjective and uncertain. This study proposes a high-resolution model for assessing spatial differences in nutrient loads based on the lattice Boltzmann method. The model was applied to Dongping Lake in China. Firstly, the contribution rates of four influencing factors, including water transfer, inflow, wind, and internal load, were calculated at different locations in the lake. Then, their proportionate contributions during different intervals to the whole lake area were calculated. Finally, the cumulative load could be calculated for any location within the lake. The validation showed that the model simulated hydrodynamics and water quality well, with relative errors between the simulated and measured water quality data smaller than 0.45. Wind increased the nutrient loads in most parts of the lake. The loads tended to accumulate in the east central area where high-frequency circulation patterns were present. Overall, the proposed water quality model based on the lattice Boltzmann method was able to simulate seven indexes. Therefore, this model represents a useful tool for thoroughly assessing nutrient load distributions in large shallow lakes and could help refine lake restoration management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)