In order to evaluate contamination by polychlorinated biphenyls (PCBs) in a tropical bay exposed to different anthropogenic pressures, samples of bivalves: mangrove oyster (Crassotrea rhizophorae), mangrove mussel (Mytella guyanensis)and clams (Anomalocardia brasiliana), were collected in different parts of Todos os Santos Bay, Bahia, Brazil. In addition, samples of bivalves and fish, purchased from a seafood market in the city of Salvador were analyzed to evaluate human exposure to PCBs through ingestion. Identification and quantification of PCBs were done by GC/MS after microwave extraction and purification with sulfuric acid. In bivalves, concentrations ranged from <0.08 to 50.1 ng g (dry weight), with the highest values being detected in mangrove oyster, followed by clams and mangrove mussel of the Subaé estuary and Madre de Deus/Mataripe; regions known to be impacted by anthropic activities. From the total of the 12 fish species analyzed, only 5 presented levels of PCBs above the detection limit, ranging from 0.23 to 4.55 ng g and 0.51 to 26.05 ng g by dry weight and lipid weight, respectively. In general, concentrations of PCBs on the bay are lower than in most regions around the world, especially those located in the Northern Hemisphere. Indexes indicated that local biota and seafood from the fish market are not adversely impacted by PCBs and do not represent a risk to human health.
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http://dx.doi.org/10.1016/j.marpolbul.2020.111070 | DOI Listing |
Aquat Toxicol
January 2025
Department of Functional Biology, Faculty of Medicine, University of Oviedo. C/ Julian Clavería s/n 33006 Oviedo, Spain.
Microplastics (MPs) are ubiquitous in the marine environment and impact organisms at multiple levels. Understanding their actual effects on wild populations is urgently needed. This study develops a toolkit to monitor changes in gene expression induced by MPs in natural environments, focusing on filter-feeding and bioindicator species from diverse ecological and taxonomic groups.
View Article and Find Full Text PDFToxics
December 2024
Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, and Institute of Marine Sciences, Shantou University, Shantou 515063, China.
With the rapid industrialization and urbanization of coastal areas, marine pollution (such as heavy metals) is increasingly contaminating the environment, posing significant public health risks. Eastern Guangdong, a key aquaculture and fisheries hub in China, has a growing market for aquatic products. Heavy metals persist in the environment and are difficult to degrade and bioaccumulate in marine organisms through the food web, presenting carcinogenic and mutagenic risks to humans, as top predators.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Department of Environmental Management, College of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062, Kampala, Uganda.
Aquaculture generates substantial amount of residual feeds and faecal matter that accumulate in the culture environment and pollute effluent-receiving water, diminishing its ecological functioning. To devise means of treating nutrient-rich aquaculture wastewater, the efficiency of integrated papyrus-bivalve mesocosms in removing nutrients was evaluated. The mesocosms were fed on water (6600 L) from one brood-stock pond and allowed to settle for 2 weeks.
View Article and Find Full Text PDFFish Shellfish Immunol
December 2024
National Engineering Research Center of Marine Facilities Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, Zhejiang, 316004, China. Electronic address:
N-methyladenosine (m6A) modification is a prevalent mRNA modification that regulates diverse biological processes in eukaryotes, including immune responses. While the role of m6A in mammalian immunity has been explored, its involvement in the immune defense of invertebrates, particularly marine bivalves which face constant pathogen challenges, remains largely unknown. Here, we investigated the function of methyltransferase-like 3 (METTL3), a key m6A "writer" enzyme, in the immune response of the marine bivalve Mytilus coruscus against Vibrio alginolyticus infection.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Fisheries, Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Research Center for Aquatic Biodiversity Conservation in the Upper Reaches of Yangtze River, Southwest University, Chongqing 400715, China. Electronic address:
Calcineurin (CN), a serine/threonine protein phosphatase regulated by Ca and calmodulin, plays a crucial role in the immune response of bivalves. In this study, we examined the effects of gene silencing of the CN subunit (HcCnAα) in Hyriopsis cumingii on the expression of genes associated with the NF-κB signaling pathway, as well as the phosphorylation of the inhibitor of NF-κB (IκB), through RNA interference (RNAi), quantitative PCR (qPCR), and Western blot (WB) analyses. The IκB kinase (HcIKK) and B-cell CLL/lymphoma 10 (HcBcl10) genes of H.
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