Effects of temperature and salinity on bioconcentration and toxicokinetics of permethrin in pyrethroid-resistant Hyalella azteca

Long-term exposure to dimefluthrin inhibits the growth of Acrossocheilus fasciatus

Dimefluthrin (DIM) is a synthetic pyrethroid insecticide commonly used for the control of pests, particularly for mosquitoes and other flying insects. However, the effects of DIM on non-target aquatic organisms are not known. In this study, we evaluated the long-term effects of DIM on juvenile Acrossocheilus fasciatus (a species of teleost fish) by exposing them to two different concentrations (0.8 μg/L and 4 μg/L) for 60 days. After 60 d of exposure, DIM induced a significant decrease in body weight and irregular, diffused villi in the intestines of A. fasciatus, accompanied by alterations in the expression of immune-related genes. Furthermore, Gene Ontology (GO) enrichment analysis revealed that among the differentially expressed genes (DEGs), all downregulated genes were enriched in processes such as small molecule/cellular amino acid metabolism, generation of precursor metabolites and energy, and phosphatase activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that the downregulated genes were associated with processes such as cytokine-cytokine receptor interaction, chemokine signaling pathway, JAK-STAT signaling pathway, intestinal immune network for IgA production, natural killer cell-mediated cytotoxicity, and antigen processing and presentation. In contrast, upregulated DEGs were linked to processes such as necroptosis, phototransduction, and Hippo signaling pathway. These results demonstrate the potential toxicity of DIM to non-target aquatic organisms, indicating the broader ecological implications of its use.

Interplay of UV-filter pollution and temperature rise scenarios on Mytilus galloprovincialis health: Unveiling sperm quality and adult physiology, biochemistry, and histology insights

Addressing the impacts of emerging contaminants within the context of climate change is crucial for understanding ecosystem health decline. Among these, the organic UV-filters 4-methylbenzylidenecamphor (4-MBC) and benzophenone-3 (BP-3) are widely used in cosmetics and personal care products. Their unique physico-chemical properties, along with their growing commercialization and consumption, have made them ubiquitous in aquatic environments through both direct and indirect releases, raising significant concerns about their potential threats to inhabiting biota. Additionally, increasing surface water temperatures exacerbate ecological risks, making it imperative to understand the implications for non-target species at different biological levels. This study investigated the short- and long-term effects of UV-filters 4-MBC or BP-3, at ecologically relevant concentrations, combined with current and predicted warming scenarios, on the performance and male reproductive health of Mytilus galloprovincialis mussel populations. Using biomarkers across sub-cellular, cellular, tissue, and individual levels, the study revealed significant physiological and biochemical impairments in both sperm cells and adults exposed to UV-filters. Temperature emerged as the primary driver influencing mussel responses and modulating the impacts of 4-MBC/BP-3, emphasizing their sensitivity to temperatures outside the optimal range and interactive effects between stressors. Specifically, sperm motility declined with increasing UV-filter concentrations, while temperature alone influenced ROS production, leading to compromised mitochondrial activity and DNA damage in the presence of combined stressors, indicative of potential reproductive impairments. Adults exhibited high UV-filter bioconcentration potential in whole tissues, compromised physiological status, morphophysiological changes in digestive glands, oxidative stress, and alterations in metabolic capacity, antioxidant defences, and biotransformation mechanisms, correlating with UV-filter exposure and temperature increase. Among the UV-filters tested, 4-MBC was the most detrimental, especially when combined with warming. Overall, this study underscores the vulnerability of M. galloprovincialis to cumulative stressors and highlights the importance of employing a multi-biomarker approach to assess and mitigate the impacts of stressors on coastal ecosystems.

Regulation and Response Mechanism of Acute Low-Salinity Stress during Larval Stages in Macrobrachium rosenbergii Based on Multi-Omics Analysis

Macrobrachium rosenbergii is an essential species for freshwater economic aquaculture in China, but in the larval process, their salinity requirement is high, which leads to salinity stress in the water. In order to elucidate the mechanisms regulating the response of M. rosenbergii to acute low-salinity exposure, we conducted a comprehensive study of the response of M. rosenbergii exposed to different salinities' (0‱, 6‱, and 12‱) data for 120 h. The activities of catalase, superoxide dismutase, and glutathione peroxidase were found to be significantly inhibited in the hepatopancreas and muscle following low-salinity exposure, resulting in oxidative damage and immune deficits in M. rosenbergii. Differential gene enrichment in transcriptomics indicated that low-salinity stress induced metabolic differences and immune and inflammatory dysfunction in M. rosenbergii. The differential expressions of MIH, JHEH, and EcR genes indicated the inhibition of growth, development, and molting ability of M. rosenbergii. At the proteomic level, low salinity induced metabolic differences and affected biological and cellular regulation, as well as the immune response. Tyramine, trans-1,2-Cyclohexanediol, sorbitol, acetylcholine chloride, and chloroquine were screened by metabolomics as differential metabolic markers. In addition, combined multi-omics analysis revealed that metabolite chloroquine was highly correlated with low-salt stress.

Influence of Salinity on the Partitioning Behavior of Six Commonly Used Pesticides in Fish Eggs

Salinity has been reported to impact the octanol-water partition coefficient of organic contaminants entering aquatic ecosystems. However, limited data are available on the impacts of salinity on their partitioning from the aqueous phase to adjacent organic compartments. The pesticides bifenthrin, chlorpyrifos, dicloran, myclobutanil, penconazole, and triadimefon were used to investigate the effects of salinity on their partitioning to capelin (Mallotus villosus) eggs in 5 practical salinity units (PSU) versus 25 PSU artificial seawater (ASW). The partitioning coefficient was significantly higher in 25 versus 5 PSU ASW for bifenthrin, chlorpyrifos, dicloran, penconazole, and triadimefon by 31%, 28%, 35%, 28%, and 20%, respectively, while for myclobutanil there was no significant difference. Moreover, pesticide partitioning to store-bought capelin eggs was consistent with the partitioning observed for the standard assay species, inland silversides (Menidia beryllina) eggs, after partitioning between the eggs and exposure solution had reached a state of equilibrium. The present study illustrates the importance of considering the influence of salinity on the environmental partitioning and fate of hydrophobic organic contaminants in aquatic ecosystems. Environ Toxicol Chem 2024;43:299-306. © 2023 SETAC.

Multi-biomarker approach for the (eco)toxicity of UV-filter environmental pollution on the Mediterranean mussel Mytilus galloprovincialis in a multiple stressor context. The case of 4-MBC under salinity shifts

Marine-coastal ecosystems are rapidly transforming because of climate change (CC). At the same time, the impacts of emerging organic contaminants (i.e., organic UV-filters) on these ecosystems are intensifying. In the Mediterranean, the consequences of these disturbances are occurring at a fast pace making this area a potential sentinel site to be investigated. While singular effects of organic UV-filters or CC-related factors on marine biota have been relatively described, their combined impact is still largely unknown. Thus, the objective of this study was to assess the long-term responses of the Mediterranean mussel Mytilus galloprovincialis towards anticipated salinity changes (decreases-S20 or increases-S40) when exposed to environmentally relevant concentrations of the UV-filter 4-methylbenzylidene camphor (4-MBC). An integrated multi-biomarker approach was applied, featuring general and oxidative stress, antioxidant and biotransformation enzyme capacity, energy metabolism, genotoxicity, and neurotoxicity biomarkers. Results showed that both projected salinities, considered separately, exerted non-negligible impacts on mussels' health status, with greater biological impairments found at S 40. Combining both stressors resulted in an evident increase in mussels' susceptibility to the UV-filter, which exacerbated the toxicity of 4-MBC. The dominant influence of salinity in the climate change-contaminant interaction played a crucial role in this outcome. The most severe scenario occurred when S 20 was combined with 4-MBC. In this situation, mussels exhibited a decrease in filtration rate, metabolic capacity and deployment of energy reserves increased, with an upregulation of biotransformation and inhibition of antioxidant enzyme activities. This exposure also led to the observation of cellular and DNA damage, as well as an increase in AChE activity. Furthermore, salinity-dependent bioaccumulation patterns were evaluated revealing that the lowest values in contaminated mussels are found at S 20. Overall, the present findings provide evidence that projected CC/pollutant scenarios may represent high risks for mussels' populations, with global relevant implications for the ecosystem level.

Microbial Diversity and Enzyme Activity as Indicators of Permethrin-Exposed Soil Health

Owing to their wide range of applications in the control of ticks and insects in horticulture, forestry, agriculture and food production, pyrethroids pose a significant threat to the environment, including a risk to human health. Hence, it is extremely important to gain a sound understanding of the response of plants and changes in the soil microbiome induced by permethrin. The purpose of this study has been to show the diversity of microorganisms, activity of soil enzymes and growth of Zea mays following the application of permethrin. This article presents the results of the identification of microorganisms with the NGS sequencing method, and of isolated colonies of microorganisms on selective microbiological substrates. Furthermore, the activity of several soil enzymes, such as dehydrogenases (Deh), urease (Ure), catalase (Cat), acid phosphatase (Pac), alkaline phosphatase (Pal), β-glucosidase (Glu) and arylsulfatase (Aryl), as well as the growth of Zea mays and its greenness indicators (SPAD), after 60 days of growth following the application of permethrin, were presented. The research results indicate that permethrin does not have a negative effect on the growth of plants. The metagenomic studies showed that the application of permethrin increases the abundance of Proteobacteria, but decreases the counts of Actinobacteria and Ascomycota. The application of permethrin raised to the highest degree the abundance of bacteria of the genera Cellulomonas, Kaistobacter, Pseudomonas, Rhodanobacter and fungi of the genera Penicillium, Humicola, Iodophanus, Meyerozyma. It has been determined that permethrin stimulates the multiplication of organotrophic bacteria and actinomycetes, decreases the counts of fungi and depresses the activity of all soil enzymes in unseeded soil. Zea mays is able to mitigate the effect of permethrin and can therefore be used as an effective phytoremediation plant.