Marine aquaculture in semi-enclosed bays can significantly influence nutrient cycling in coastal ecosystems. However, the impact of marine aquaculture on the dynamics of dissimilatory nitrate reduction processes (DNRPs) and the fate of reactive nitrogen remain poorly understood. In this study, the rates of DNRPs and the abundances of related functional genes were investigated in aquaculture and non-aquaculture areas. The results showed that marine aquaculture significantly increased the denitrification (DNF) and dissimilatory nitrate reduction to ammonium (DNRA) rates and decreased the rate of anaerobic ammonium oxidation (ANA), as compared with non-aquaculture sites. DNF was the dominant pathway contributing to the total nitrate reduction, and its contribution to the total nitrate reduction significantly increased from 66.72% at non-aquaculture sites to 78.50% at aquaculture sites. Marine aquaculture can significantly affect the physicochemical characteristics of sediment and the abundances of related functional genes, leading to variations in the nitrate reduction rates. Although nitrate removal rates increased in the marine aquaculture area, ammonification rates and the nitrogen retention index in the aquaculture areas were 2.19 and 1.24 times, respectively, higher than those at non-aquaculture sites. Net reactive nitrogen retention exceeded nitrogen removal in the aquaculture area, and the retained reactive nitrogen could diffuse with the tidal current to the entire bay, thereby aggravating N pollution in the entire study area. These results show that marine aquaculture is the dominant source of nitrogen pollution in semi-enclosed bays. This study can provide insights into nitrogen pollution control in semi-enclosed bays with well-developed marine aquaculture.
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http://dx.doi.org/10.1016/j.jes.2020.12.025 | DOI Listing |
Fish Shellfish Immunol
January 2025
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, School of Marine Sciences, Ningbo University, Ningbo 315211, P.R. China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Meishan Campus, Ningbo University, Ningbo 315832, China; Key Laboratory of Aquacultural Biotechnology of Ministry of Education, Ningbo University, Ningbo 315211, P.R. China. Electronic address:
The liver-expressed antimicrobial peptide 2 (LEAP2) is gaining recognition for its immune regulatory functions beyond direct antimicrobial activity. In this study, we investigated the role of mudskipper (Boleophthalmus pectinirostris) LEAP2 (BpLEAP2) in enhancing the survival, gut health, and immune resilience against Edwardsiella tarda infection. Pre-oral delivery of BpLEAP2 significantly improved survival rates and mitigated infection-induced damage to the gut, as evidenced by preserved villus length and goblet cell count.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao 266100, China. Electronic address:
The excessive use of antibiotics in mariculture has surpassed permitted levels, leading to their release into surrounding waters and accumulation in cultured organisms, which poses risks to human health and highlighting the urgent need for alternatives to reduce antibiotic use. Therefore, the present study aimed to test four microbes including Debaryomyces hansenii, Ruegeria mobilis, Lactobacillus plantarum and Bacillus subtilis, on lowering Vibrio, promoting population increase and survival of Brachionus plicatilis. The digestive enzymes activity including α-amylase, lipase and protease, microbial retention and biochemical composition of rotifers were analyzed.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
College of Material, Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, Zhejiang 311121, China. Electronic address:
Aquaculture organisms may accumulate metals to induce health risks. Compared with the focus on total contents, chemical-specific risk assessment makes reasonable but is rare. Herein, we elucidated occurrence of twelve metal compounds in shrimp and fish (edible muscle, one of major metal-containing and generally targeted organs), water, sediment, and feedstuff from two aquaculture ponds in Zhejiang Province (one of the major aquatic production and consumption areas).
View Article and Find Full Text PDFRSC Adv
January 2025
University of Split, Faculty of Science, Department of Chemistry R. Bošković 33 Split Croatia
Quaternary ammonium compounds (QACs) have served as essential antimicrobial agents for nearly a century due to their rapid membrane-disrupting action. However, the emergence of bacterial resistance and environmental concerns have driven interest in alternative designs, such as "soft QACs", which are designed for enhanced biodegradability and reduced resistance potential. In this study, we explored the antibacterial properties and mechanisms of action of our newly synthesized soft QACs containing a labile amide bond within a quinuclidine scaffold.
View Article and Find Full Text PDFCurr Microbiol
January 2025
Applied Phycology and Biotechnology Division, CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, 364001, India.
The present study explores the microbial community associated with the industrially important red seaweed Gracilaria dura to determine the diversity and biotechnological potential through culture and metagenomics approaches. In the first part of the investigation, we isolated and characterized 75 bacterial morphotypes, with varied colony characteristics and metabolic diversity from the wild seaweed. Phylogenetic analysis identified isolates in Proteobacteria, Firmicutes, and Actinobacteria, with Bacillus sp.
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