Bioaccumulation of persistent organic pollutants in the gonads of Barbus barbus (Linnaeus, 1758)

Tissue bioaccumulation and distribution of organic contaminants in Brazilian guitarfish Pseudobatos horkelii reveal a concerning impact of contraceptive hormones and fecal sterols

The critically endangered Brazilian guitarfish faces significant threats from environmental contamination. Assessing the impacts of such stressor is paramount from a conservational perspective. This study investigated the concentrations, distribution and accumulation patterns of organic contaminants in pregnant Brazilian guitarfish Pseudobatos horkelii. Blood, gill, gonad, liver, and muscle concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers, fecal sterols, and synthetic hormones used as human contraceptives were assessed. Synthetic hormones, especially D-norgestrel, showed the highest concentrations, mainly in the liver. Together with the results of fecal sterols, this finding suggests that guitarfish are exposed to sewage discharge. OCPs, especially hexachlorobenzene, mirex, endosulfans, and drins, showed considerably high concentrations, indicating the relevance of agricultural inputs. PCBs presented significant concentrations in the muscle, indicating long-term exposure, in contrast with other analytes that were primarily concentrated in the liver. These results have conservational implications, since contaminants analyzed herein have endocrine disruptive effects.

Review of scientific literature on available methods of assessing organochlorine pesticides in the environment

Organochlorine pesticides (OCPs) are persistent organic pollutants (POPs) widely used in agriculture and industry, causing serious health and ecological consequences upon exposure. This review offers a thorough overview of OCPs analysis emphasizing the necessity of ongoing work to enhance the identification and monitoring of these POPs in environmental and human samples. The benefits and drawbacks of the various OCPs analysis techniques including gas chromatography-mass spectrometry (GC-MS), gas chromatography-electron capture detector (GC-ECD), and liquid chromatography-mass spectrometry (LC-MS) are discussed. Challenges associated with validation and optimization criteria, including accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ), must be met for a method to be regarded as accurate and reliable. Suitable quality control measures, such as method blanks and procedural blanks, are emphasized. The LOD and LOQ are critical quality control measure for efficient quantification of these compounds, and researchers have explored various techniques for their calculation. Matrix interference, solubility, volatility, and partition coefficient influence OCPs occurrences and are discussed in this review. Validation experiments, as stated by European Commission in document SANTE/11813/2017, showed that the acceptance criteria for method validation of OCP analytes include ≤20 % for high precision, and 70-120 % for recovery. This may ultimately be vital for determining the human health risk effects of exposure to OCP and for formulating sensible environmental and public health regulations.

Application of gas chromatographic data and 2D molecular descriptors for accurate global mobility potential prediction

Mobility is a key feature affecting the environmental fate, which is of particular importance in the case of persistent organic pollutants (POPs) and emerging pollutants (EPs). In this study, the global mobility classification artificial neural networks-based models employing GC retention times (RT) and 2D molecular descriptors were constructed and validated. The high usability of RT was confirmed based on the feature selection step performed using the multivariate adaptive regression splines (MARS) tool. Although RT was found to be the most important, according to Kruskal-Wallis ANOVA analysis, it is insufficient to build a robust model, which justifies the need to expand the input layer with 2D descriptors. Therefore the following molecular descriptors: MPC10, WTPT-2, AATS8s, minaaCH, GATS7c, RotBtFrac, ATSC7v and ATSC1p, which were characterized by a high predicting potential were used to improve the classification performance. As a result of machine learning procedure ten of the most accurate neural networks were selected. The external validation showed that the final models are characterized by a high general accuracy score (85.71-96.43%). The high predicting abilities were also confirmed by the micro-averaged Matthews correlation coefficient (MAMCC) (0.73-0.88). To evaluate the applicability of the models, new retention times of selected POPs and EPs including pesticides, polycyclic aromatic hydrocarbons, pharmaceuticals, fragrances and personal care products were measured and used for mobility prediction. Further, the classifiers were used for photodegradation and chlorination products of two popular sunscreen agents, 2-ethyl-hexyl-4-methoxycinnamate and 2-ethylhexyl 4-(dimethylamino)benzoate.

Freshwater as a Sustainable Resource and Generator of Secondary Resources in the 21st Century: Stressors, Threats, Risks, Management and Protection Strategies, and Conservation Approaches

This paper is a synthetic overview of some of the threats, risks, and integrated water management elements in freshwater ecosystems. The paper provides some discussion of human needs and water conservation issues related to freshwater systems: (1) introduction and background; (2) water basics and natural cycles; (3) freshwater roles in human cultures and civilizations; (4) water as a biosphere cornerstone; (5) climate as a hydrospheric 'game changer' from the perspective of freshwater; (6) human-induced stressors' effects on freshwater ecosystem changes (pollution, habitat fragmentation, etc.); (7) freshwater ecosystems' biological resources in the context of unsustainable exploitation/overexploitation; (8) invasive species, parasites, and diseases in freshwater systems; (9) freshwater ecosystems' vegetation; (10) the relationship between human warfare and water. All of these issues and more create an extremely complex matrix of stressors that plays a driving role in changing freshwater ecosystems both qualitatively and quantitatively, as well as their capacity to offer sustainable products and services to human societies. Only internationally integrated policies, strategies, assessment, monitoring, management, protection, and conservation initiatives can diminish and hopefully stop the long-term deterioration of Earth's freshwater resources and their associated secondary resources.

Anthropogenic Sewage Water Circuit as Vector for SARS-CoV-2 Viral ARN Transport and Public Health Assessment, Monitoring and Forecasting-Sibiu Metropolitan Area (Transylvania/Romania) Study Case

Water is a risk factor for epidemics of waterborne diseases with effects on human health. In 2019, new viral pneumonia cases occurred in China and spread worldwide. The aim of this study was to assess the feasibility and accuracy of a wastewater-based epidemiological (WBE) monitoring tool in a SARS-CoV-2 hot spot (Sibiu City metropolitan area), namely to highlight the correlation between the number of infections on the days of sampling and the amount of viral RNA detected in wastewater. Wastewater samples were collected once a week, and viral RNA was extracted and quantified. In parallel, the daily number of SARS-CoV-2 infections was obtained from the local council. The correlation between the number of infections and viruses detected in sewage was measured by Pearson correlation coefficients. The results show the amount of viral RNA in the wastewater is directly correlated with the number of infections reported in the week up to the sampling day and also the number of infections reported for the sampling day. Moreover, correlation coefficients show the amount of viral RNA in wastewater increases in advance of the increase in reported infection cases. Therefore, WBE can be used as a tool for monitoring virus spread trends in human communities and can help anticipate the trend of this type of viral infection.

Toxicity evaluation and oxidative stress response of fumaronitrile, a persistent organic pollutant (POP) of industrial waste water on tilapia fish (Oreochromis mossambicus)

The study was designed to determine the impact of acute toxicity of fumaronitrile exposure through tissue damaging, oxidative stress enzymes and histopathological studies in gills, liver and muscle cells of freshwater tilapia fish (Oreochromis mossambicus). In gill, liver, and muscle cells, biochemical indicators such as tissue damage enzymes (Acid Phosphatase (ACP), Alkaline Phosphatase (ALP), and Lactate Dehydrogenase (LDH)) and antioxidative enzymes (Superoxide Dismutase (SOD); Catalase (CAT); Glutathione-S-transferase (GST); Reduced Glutathione (GSH); Glutamate oxaloacetate transaminase (GOT) and Glutamate pyruvate transaminase (GPT) were quantified in the time interval of 30, 60 and 90 days exposure to the fumaronitrile. After 90 days, under 6 ppb exposure conditions, the acid phosphatase (ACP) levels of fish increased significantly in the gills (3.439 μmol/mg protein/min), liver (1.743 μmol/mg protein/min), and muscles (2.158 μmol/mg protein/min). After 90 days of exposure to the same concentration and days, ALP activity increased significantly in gills (4.354 μmol/mg protein/min) and liver (1.754 μmol/mg protein/min), but muscle cells had a little decrease in ALP activity (2.158 μmol/mg protein/min). The LDH concentration in gills following treatment with fumaronitrile over a period of 0-90 days was 3.573 > 3.521 > 2.245 μmol/mg protein/min over 30 > 60 > 90 days. However, at the same dose and treatment duration, a greater LDH level of 0.499 μmol/mg protein/min was found in liver and muscle cells. Histopathological abnormalities in the gills, liver, and muscle cells of treated fish were also examined, indicating that fumaronitrile treatment generated the most severe histological changes. The current study reveals that fumaronitrile exposure has an effect on Oreochromis mossambicus survival, explaining and emphasising the risk associated with this POP exposure to ecosystems and human populations.

Coştei Hydrographic Diversion Node, a Historical Environment Quality and Biological Resources Accessibility Game Changer; Anthropogenic Induced Problems and Sustainable Solutions ‒ An Ichthyologic Perspective

26 fish species were affected by the Coştei historical diversion hydrotechnical system build in 1758. In order to mitigate the negative effects produced by this hydrotechnical work on the fish, a migration system, of nature-like meandering by pass type was proposed. The dimensions of this channel and the slope of about 2% allow fish, and other aquatic organisms to move upstream and downstream of the spillway.

A Study on Marine Fishery Resources of Andhra Pradesh: Ecological Aspects and Morphometrics of Common Marine Fishes of Visakhapatnam ‒ Protein Content and Bioaccumulation of Heavy Metals in Pomfret Fish Species

212 marine fishery resources were recorded in the waters of Andhra Pradesh State. Morphometric data was provided for 20 edible fishery resources landing at the fishing harbour of Visakhapatnam. The harbour area is polluted due to influx of various industrial effluents and domestic sewage. In Pampus argenteus, P. chinensis and Parastromateus niger, the total protein content is 16.24-19.58%. Further, arsenic concentration in muscle and gill portions individually or combined in all three of the species is highly negligible. Cadmium, mercury, and lead levels in the muscle and gills of these species are within or slightly above the recommended limits set by EU (2006) and FAO (2003), FAO/WHO (2011), MAFF, and FSSAI (2011) indicating that the consumption of these fishes is not harmful.

A Short Review on the Biological Characteristics of the Species Esox Lucius, Linnaeus, 1758 in Caspian Sea Basin (Iran)

The Esox genus belongs to the family Esocidae. It is a freshwater fish that can be found in different parts of Europe, Asia, and North America. The Northern Pike, is a carnivorous fish, member of the only remaining genus of the Esocidae. This fish prefers to lead a solitary life due to the disadvantages of the presence of individuals of the same species which compete for food resources and territory. Waiting for a suitable situation to catch prey is a favoured hunting method, which means this specific species is a lie-in-wait predator. The elongated body and the broad snout are the most striking features used for the identification of this species. This lie-in-wait carnivorous predator mostly feeds on invertebrates and fishes. The species spawns annually. The special living conditions of this species and their endangered environment have made it necessary to avoid any acts that can affect their life quality.

Sediments as Factor in the Fate of the Threatened Endemic Fish Species Romanichthys Valsanicola Dumitrescu, Bănărescu and Stoica, 1957 (Vâlsan River Basin, Danube Basin)

The main emphasis of this paper is on the negative effects of sedimentation on the most highly endangered fish of Europe Romanichthys valsanicola and the habitats of its main trophic resource Rhithrogena semicolorata. Some inexpensive and easy-to-implement solutions are identified and proposed (dam reservoir related recommendations for basin sediments management, forestry related recommendations for sediment basin management, basin sediments general management recommendations, riverbed ecological reconstruction approach proposal, etc.) in the paper with the same conservative purpose for Romanichthys valsanicola species in the actual situation of habitat loss and drastic regress of this globaly-unique fish population.

Adding the Mureş River Basin (Transylvania, Romania) to the List of Hotspots with High Contamination with Pharmaceuticals

Background: The Mureș River Basin is a long-term heavily polluted watershed, in a situation of climate changes with decreasing water flow and related decreasing dilution capacity. Here, a mixture of emerging pollutants such as pharmaceuticals were targeted to reveal potential risks regarding the natural lotic ecosystems. Due to the continuous discharge into the environment, pharmaceuticals are gaining persistent organic pollutant characteristics and are considered emerging pollutants. Based on the hazard quotient, this research highlights the dangerous concentrations of carbamazepine, ibuprofen, furosemide, and enalapril in river water. Results: High levels of four pharmaceutical compounds (carbamazepine, ibuprofen, furosemide, and enalapril) and some of their derived metabolites (enalaprilat, carboxyibuprofen, 1-hydroxyibuprofen, and 2-hydroxyibuprofen) were reported in our study in the Mureș River Basin. Overall, pharmaceutical concentrations were found to be highest in the wastewater treatment plant (WWTP) effluent, median downstream of the WWTP, and lowest upstream of the WWTP, as was expected. For all pharmaceutical compounds tested, we recorded concentrations above the limit of quantification (LOQ) in at least one of the sites tested. Carbamazepine exhibited the highest mean values upstream, downstream, and at the WWTP. As expected, the highest concentrations for all the studied pharmaceutical compounds were detected in the WWTP effluent. All Hazard Quotient (HQ) values were below one (on a logarithmic scale in base 10), with the highest values in the WWTP and the lowest in the river upstream of the WWTP. The HQ intervals were in the same range for furosemide, carbamazepine, and ibuprofen at each of the three different sites: upstream WWTP effluent, and downstream. The interval for enalapril stands out as having the lowest HQ at all three sites. Conclusions: Based on these results, the large and complex hydrographical system Mureș River Basin was transformed from a grey area, with little information about pharmaceutical contamination, to a hotspot in terms of contamination with emerging pollutants. Pharmaceutical compound concentrations were found to be the highest in WWTP effluents. The WWTP effluent concentrations were among the highest in Europe, indicating that treatment plants are the primary source of water pollution with pharmaceuticals compounds. The detected levels were higher than the safety limit for carbamazepine and ibuprofen. The determined HQ values imply that the measured levels do pose a threat to the environment for the studied pharmaceuticals. Based on the obtained results, human communities can assess, monitor, predict, and adapt in time to these already-present regional challenges and risks for sustainable use of natural resources, including water and associated products and services.

Optimization of barbel (Barbus Barbus L.) fertilization and effects of ovarian fluid when there are controlled conditions for gamete activations

Fertilization is one of the most important procedures in artificial reproduction and it directly affects the reproduction outcome. When there is optimization of fertilization, there can be a positive effect on subsequent reproductive processes and economic aspects of aquaculture. This study was conducted to determine time for which oocytes and sperm of barbel Barbus barbus retain fertilization capacity following placement in freshwater. Furthermore, the amount of ovarian fluid, excreted by fish during spawning with eggs (OFI; %) was determined, along with the chemical composition and effects on fertilization were determined. Gametes, ovarian fluid, and seminal plasma from barbel spawning specimens of the F₄ generation were used to conduct the study. Ovarian fluid accounted for 14%-68% of contents of the mass released at spawning and post-spawning composition differed depending on whether hormonal treatments were utilized for control of reproduction. There was an association (R² = 0.982; P = 0.000) between the pH of ovarian fluid and the barbel embryo survival rate. There was the greatest survival rate (>60 %) when the pH range of 7.9-8.4 and there was a lesser embryo viability when pH values were lesser or greater than values within this range (P <  0.05). The results from the study indicate that barbel eggs retain fertilization capacity longer (as long as 210 s) after activation by placement in fresh water than spermatozoa (about 30 s).

Inhibiting the influence of ovarian fluid on spermatozoa activation and spermatozoa kinetic characteristics in the common barbel Barbus barbus

As a result of evolution, various finfish species have developed different breeding strategies. However, there are some similarities, and one of them is the positive effect of ovarian fluid on spermatozoa. The opposite of this phenomenon was found in the common barbel (Barbus barbus). The present study analyzed the effect of ovarian fluid (OF), distilled water (DW) and Woynarovich solution (WS) on the motility, longevity and kinetics of barbel spermatozoa. These spermatozoa parameters were also evaluated with various dilutions of ovarian fluid (OF) in relation to distilled water [0:4 (Group OF 0%), 1:3 (Group OF 25%), 1:1 (Group OF 50%), 3:1 (Group OF 75%), 4:0 (Group OF 100%)] and spermatozoa reactivation after a 30 s (Group OFR_30s 100%) treatment in ovarian fluid. The motility analysis was carried out using computer-assisted semen analysis (CASA). The negative interaction of ovarian fluid with spermatozoa motility in the same fish species was recorded for the first time. In pure ovarian fluid, the average spermatozoa motility (MOT) decreased significantly (1.40 ± 0.94%). The negative effect of ovarian fluid-to-spermatozoa motility was reversible, and after a 30 s treatment in ovarian fluid and later dilution with water, spermatozoa motility was reactivated (from 2.25 ± 0.53% vs 69.78 ± 6.02%). The use of Woynarovich solution as an activator of spermatozoa movement had a positive effect (P < 0.05) on spermatozoa movement longevity (motility up to 90 s) and the percentage of motile spermatozoa compared to distilled water (up to 45 s) and ovarian fluid (P < 0.05).