Shellfish Tissue Research Articles

Metal concentrations in fish, crabs, and bivalve molluscs from marine waters adjacent to a multi-metals smelter and refinery

Metal concentrations were determined in tissues of finfish, crabs, and bivalve molluscs collected from marine waters near Port Pirie, South Australia, the site of a long-standing multi-metals smelter and refinery. A general trend of tissue metal concentrations in order of highest to lowest was observed in bivalves > crabs > finfish. A lead concentration of 158 ± 6.6 mg/kg (wet wt.) was observed in blue mussels (Mytilus galloprovincialis) sampled close to the smelter. Lead concentrations correlated positively with proximity to the smelter in all biota analysed. Similar relationships were observed for cadmium, copper, zinc and selenium in all biota except razorfish (Pinna bicolor; Bivalvia: Pinnidae), which showed no correlation with proximity to the smelter for these metals. Inorganic arsenic concentrations were below the limit of reporting in the majority of the analysed samples, however inorganic arsenic concentrations in blue swimmer crabs (Portunus armatus) and blue mussels correlated with proximity to the smelter. Mercury concentrations in the biota analysed were generally low and showed variable relationships with proximity to the smelter, with no significant correlation observed in finfish and razorfish, a significant positive correlation in blue mussels, and a significant negative correlation in blue swimmer crabs. This is the first major study of metal concentrations in recreationally-targeted marine species near Port Pirie species for more than two decades. Comparison with data from previous studies conducted shows little change in tissue metal concentrations in marine biota near Port Pirie over the past 40 years.

Assessing methods for detecting Alexandrium catenella (Dinophyceae) and paralytic shellfish toxins in Southeast Alaska.

Blooms of Alexandrium catenella threaten to disrupt subsistence, recreational, and commercial shellfish harvest in Alaska, as the paralytic shellfish toxins (PSTs) produced pose a serious public health risk and can lead to costly shutdowns for shellfish farmers. Current methods of PST detection in the region range from monitoring programs utilizing net tows to detect A. catenella to direct shellfish tissue testing via mouse bioassay (MBA) for commercial aquaculture harvest, as well as various optional testing methods for subsistence and recreational harvesters. The efficacy and feasibility of these methods vary, and they have not been directly compared in Southeast Alaska. In this study, we sought to assess and compare A. catenella and PST early detection methods to determine which can provide the most effective and accurate warning of A. catenella blooms or PST events. We found microscope counts to be variable and prone to missing lower numbers of A. catenella, which may be indicative of bloom formation. However, quantitative polymerase chain reaction (qPCR) significantly correlated with microscope counts and was able to effectively detect even low numbers of A. catenella on all sampling days. Paralytic shellfish toxin concentrations measured by enzyme-linked immunosorbent assay and MBA significantly correlated with each other, qPCR, and some microscope counts. These results show that qPCR is an effective tool for both monitoring A. catenella and serving as a proxy for PSTs. Further work is needed to refine qPCR protocols in this system to provide bloom warnings on an actionable timescale for the aquaculture industry and other shellfish harvesters. Integr Environ Assess Manag 2024;20:2189-2202. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Комплексная оценка экологического состояния участка трансграничной реки Нарвы

A comprehensive study of the ecological state on the transboundary Narva River (Russia –Estonia border) downstream of Ivangorod, Kingisepp District, Leningrad Region, was carried out. It included the determination of chemical indicators of pollution of the natural river water, with an emphasis on some heavy metals content in water, sediments and soft tissues of local filter-feeding mollusks; the latter were used as bioindicators of river pollution in this location. Zn was determined in maximum concentrations in bottom sediments, then Cu, to a lesser extent Pb, Cd and Ni. The coefficient of metal bioconcentration calculated in soft tissues of mollusks showed maximum for Zn and Cu, to a lesser extent for Pb, Cd and minimum for Ni. However, such values have no negative effect on local biota as shown by physiological testing of bivalves from study site. The functional assessment of bivalves by non-invasive cardiac rhythm recording made it possible to characterize their functional status and adaptive capabilities as good. The relative abundance of hydrocarbon-oxidizing bacteria in the digestive tract of mollusks from the Narva River has been determined as an indicator of environmental pollution by oil products. It was noted that the number of hydrocarbon-oxidizing bacteria does not exceed the values characteristic of the reference waters of the Eastern Gulf of Finland. Based on the totality of the studies, it was concluded that the river waters in the studied location can be characterized as slightly polluted and its ecological status as of a good quality.

Contamination Status and Acute Dietary Exposure Assessment of Paralytic Shellfish Toxins in Shellfish in the Dalian Area of the Yellow-Bohai Sea, China

The Yellow-Bohai Sea is an important semi-enclosed continental shelf marginal seas with an intensive aquaculture industry in China. The current study analyzed the contamination status and the time variations of paralytic shellfish toxins (PSTs) in shellfish between 2019 and 2020 from the Yellow-Bohai Sea in the Dalian area and estimated the acute health risks to consumers in China. A total of 199 shellfish samples (including 34 Pacific oysters, 25 Mediterranean blue mussels, 34 Manila clams, 36 bay scallops, 34 veined rapa whelks and 36 bloody clams) were analyzed from four representative aquaculture zones around the Yellow-Bohai Sea in Dalian. Among the samples, scallops and blood clams were the shellfish species with the highest detection rate of PSTs (94.4%), and the highest level of PSTs was detected in scallops with 3953.5 μg STX.2HCl eq./kg (μg STX.2HCL equivalents per kg shellfish tissue), followed by blood clams with 993.4 μg STX.2HCl eq./kg. The contents of PSTs in shellfish showed a time variation trend, and autumn was the season of concern for PST contamination in Dalian. For general Chinese consumers, the probability of acute health risks to shellfish consumers from dietary exposure to PSTs was around 13%. For typical consumers in coastal areas of China, especially those with higher shellfish intake, there was an acute health risk associated with exposure to PSTs through shellfish consumption during the occurrence of harmful algal blooms. It is suggested that the government continue to strengthen the monitoring of the source of PSTs and the monitoring of harmful algal blooms and give reasonable advice on shellfish consumption for consumers in coastal areas, such as not eating scallop viscera.

A Structural Analysis of Host-Parasite Interactions in Achatina fulica (Giant African Snail) Infected with Angiostrongylus cantonensis.

Angiostrongylus cantonensis is a nematode parasite that resides in the pulmonary arteries of rodents, serving as its definitive hosts. The life cycle involves several species of non-marine gastropods as intermediate hosts, and the African giant snail Achatina fulica is considered one of the most important around the world. Experimental data concerning A. cantonensis infection in the African giant snail remains notably limited. This helminth causes eosinophilic meningitis or meningoencephalitis in humans, representing an emergent zoonosis in Brazil. Understanding the host-parasite relationship through the application of new tools is crucial, given the complex interaction between zoonosis and the intricate mechanisms involving wild/human hosts, parasite adaptation, and dispersion. The objective of this study was to employ SEM as a novel methodology to understand the structural organization of the host tissue, particularly the granuloma formation. This sheds light on the complex balance between A. fulica and A. cantonensis. Nine three-month-old snails were randomly selected and exposed for 24 h to a concentration of 2000 L1/dose of A. cantonensis. A necropsy was performed 37 days after the infection, and the samples were examined using light and scanning electron microscopy (SEM). The histopathological results revealed third-stage larvae of A. cantonensis associated with granulomas distributed throughout the head-foot mass, mantle, and kidney. Scanning electron microscopy of the histological section surface showed that the granuloma is surrounded by a cluster of spherical particles, which are distributed in the region bordering the larvae. This reveal details of the nematode structure, demonstrating how this methodology can enhance our understanding of the role of granulomas in molluscan tissue. The structural characteristics of granuloma formation in A. fulica suggest it as an excellent invertebrate host for A. cantonensis. This relationship appears to provide protection to the parasite against the host's immune defense system while isolating the snail's tissue from potential exposure to nematode antigens.

Features of the reproductive biology of representatives of the genus Haslea Simonsen (Bacillariophyta), allowing the use of classical breeding methods

The application of the classical selection of diatoms on the example of the genus Haslea is considered. The ability of some representatives of this genus to synthesize marennine and marennine-like pigments is interesting to researchers and owners of oyster farms because these unique pigments can colorise the tissues of mollusks in a greenish color and improve their organoleptic properties. It has been shown that marennine has antibacterial, antiviral, antioxidant and other biological activities. It is assumed that the efficiency of marennine biosynthesis can be increased by obtaining highly productive strains by selection, which was not previously carried out in diatoms. The assessment of the possibility and prospects of applying the methods of classical breeding in relation to representatives of the genus Haslea is given. It is shown that significant success has been achieved to date in the study of the life cycle, crossing systems and other features of the reproductive biology of representatives of the genus Haslea, which allows them to carry out classical selection by selection, hybridization and obtaining descendants of the next generation.

Bioavailability and health risk assessment of Zn and Cd in edible tissues of two typical shellfish species using in vitro gastrointestinal digestion

Dynamic extraction of edible tissues of Jinjiang oyster (Crassostrea rivularis) and Flower clam (Paphia undulata) was conducted using a fully biomimetic digestion (in vitro) method. The impact of different cooking methods on the bioavailability of Zn and Cd in the edible shellfish tissues was analyzed, and the human health risk of Zn and Cd was evaluated. The results show that the gastric biomimetic extractions of Zn and Cd in unheated samples of C. rivularis and P. undulata were higher than those in the intestinal biomimetic extraction. The extraction patterns of cooked samples were consistent with those of raw samples. The bioavailability of Zn and Cd in cooked samples of C. rivularis was 94.9% and 82.5%, respectively, indicating increased Zn bioavailability but decreased Cd bioavailability compared to the raw samples. The bioavailability of Zn and Cd in cooked samples of P. undulata was 85.1% and 83.0%, respectively, both of which decreased compared to the raw samples. Consumption of C. rivularis can provide 21.0% to 34.2% of the daily required Zn intake, while consumption of P. undulata can provide 3.8% to 6.4%. The intake of Cd from both shellfish species is below the monthly tolerable intake recommended by FAO/WHO. Consuming cooked C. rivularis can increase the intake of Zn and decrease the intake of Cd.

Bioaccumulation of heavy metals in commercially important marine species from Puducherry coast, Southeast India

Safety of aquatic products is one of the important public health concerns globally, mainly in developing countries with culture and capture fisheries. In the present study, the bioaccumulation of heavy metals such as Cu, Zn, Cr, Pb, As and Cd in the muscle tissues of crustaceans, molluscs and finfishes collected from the Pondicherry (Puducherry) coast were determined using inductively coupled plasma mass spectrometry (ICP-MS). Among the analysed organisms, maximum concentration of Cu (26.1 ±0.83μg/g) was observed in Perna viridis, Zn (25.03 ±0.82μg/g) in Charybdis feriata, 1.33 ±0.04μg/g of Cr in Atule mate, 1.48 ±1.05μg/g of Pb in Sardinella fimbriata, 2.88±2.16μg/g of Cd in Nemipterus jopanicus and 0.72 ±0.15μg/ g of As in Decapterus russelii. Among the various marine organisms studied, the benthic species showed higher metal accumulation than the pelagic species. The heavy metal accumulation level differed significantly between the organisms. The elemental levels in analysed organisms are within the maximum acceptable levels proposed by various international standards and guidelines. Hazard index (HI) of all the analysed marine organisms showed distinctly lower values than threshold value as suggested by World Health Organization (WHO) and Food Safety and Standards Authority of India (FSSAI) for all the studied elements. Overall, the analysed marine organisms are considered safe for human consumption and export. This study provides the baseline data on heavy metal contamination in edible marine organisms from the Puducherry coast of India that will help in developing effective management plans and continuous monitoring of the coast.

The Contents of Trace Elements in Tissues of Gastropod Mollusks of the Family Buccinidae (Gastropoda) off the Coasts of Southeastern Sakhalin (Sea of Okhotsk)

The Contents of Trace Elements in Tissues of Gastropod Mollusks of the Family Buccinidae (Gastropoda) off the Coasts of Southeastern Sakhalin (Sea of Okhotsk)

The screening and prioritization of contaminants of emerging concern in the marine environment based on multiple biological response measures

There is ample evidence that a range of anthropogenic chemicals occur in the aquatic environment, some of which have the potential to cause harm. Contaminants of Emerging Concern (CECs) are a subset of anthropogenic compounds that are poorly characterized in terms of effects and occurrences, and that are generally unregulated. Due to the sheer number of chemicals used, it is necessary to identify and prioritize those that may cause biological impacts.A key challenge of doing so is the lack of traditional ecotoxicological information. The utilization of in vitro exposure-response studies or benchmarks based on in vivo data can provide a basis for developing threshold values for evaluation of potential impacts. There are challenges, including understanding the accuracy and range of application for modeled measures and translating in vitro response information from receptor models to apical endpoints. Despite this, the use of multiple lines of evidence increases the range of available information, and supports a weight-of-evidence approach to inform the screening and prioritization of CECs in the environment.The objective of this work is to perform an evaluation of CECs detected in an urban estuary, and to identify those that are most likely to elicit a biological response. Monitoring data from marine water, wastewater, and fish and shellfish tissue samples from 17 different campaigns combined with multiple biological response measures were compared with appropriate threshold values. CECs were categorized based on their potential to elicit a biological response; the uncertainty, based on consistency of lines of evidence, was also evaluated. Two-hundred-fifteen CECs were detected. Fifty-seven were identified as High Priority (likely to cause a biological effect), and 84 as Watch List (potential to cause biological effects). Due to the extent of the monitoring and range of the lines of evidence, this approach and results are applicable to other urbanized estuarine systems.

Macro and microplastic intake in seafood variates by the marine organism's feeding behaviour: Is it a concern to human health?

Seafood is considered one of the healthiest sources of food intake for humans, mainly because of its high protein content. However, oceans are among the most polluted environments, and microplastics have been widely reported to be ingested, absorbed or bioaccumulated by marine organisms. The different feeding behaviour may contribute to infer the amounts of microplastic particles accidently intake by marine organisms. We investigated the putative levels of microplastics in different edible species of fish, molluscs, and crustaceans. Plastic fragments larger than 200 μm were detected in the digestive tract of 277 out of 390 specimens (71.5 ± 22.2%) of the 26 different species analysed. There was no evidence of microplastic translocation or bioaccumulation in the muscle tissue of fish, molluscs, and crustaceans. Organisms with carnivorous feeding habits had the highest prevalence of plastic ingestion (79 ± 9.4%), followed by planktivorous species (74 ± 15.5%), and detritivorous species (38 ± 36.9%), suggesting a transfer through the food chain. Moreover, we found evidence that species with less selective feeding habits may be the most affected by the ingestion of large microplastic particles. Our results provide further evidence to the ubiquitous presence of microplastics in marine organisms representing a direct threat to marine wildlife, and to human health with potential consequences for future generations according to the One Health initiatives approach.

Content of Trace Elements in Tissues of Gastropod Mollusks of the Family Buccinidae (Gastropoda) off the Coasts of South-Eastern Sakhalin (the Sea of Okhotsk)

The content of Pb, Cd, Cu, Cr, Mn, Ni, Fe, and As in the muscle, mantle, and digestive glands of the gastropod mollusks Neptunea excelsior, N. behringiana, N. multistriata, and N. varicifera, as well as Buccinum verkruezeni, living near the coasts of the South-Eastern Sakhalin has been estimated. Representatives of the ge-nera Neptunea and Buccinum showed some differences in the ranges of variation and series of value sequences of trace element concentrations in the muscle. Exceeding the hygienic standard for the content of As in the hepatopancreas was found in all the studied mollusks, and in the muscle – in all, except for N. behringiana. The maximum permissible level of Cd concentration was exceeded in the hepatopancreas of N. multistriata.

Аккумуляция ртути в двустворчатых моллюсках в гидроэкосистеме устьевой области реки Красная (Вьетнам)

The article presents analysis of mercury content in different tissues such as gills, mantle, hepatopancreas and body (leg) in 4 species of bivalve molluscs in the estuary of the Red River in Vietnam. The studies were carried out in 2016–2021 during the main hydrological seasons (during the summer flood and winter low water) at 37 stations in the delta and estuarine coast of the Red River. There are shown the dependences of mercury content in mollusc tissues on the age parameters (length and mass of tissues) and on the content of pollutant in dissolved, suspended forms of near-bottom water layers and in bottom sediments. The mercury content in the tissues of molluscs varies whithin 0,023 ± 0,001 to 0,459 ± 0,007 mg/kg wet weight. The highest content of mercury was found in the hepatopancreas 
 of Austriella corrugata, and the lowest - in the leg of Lutraria rhynchaena. Significant close positive correlations were registered between the mercury concentrations in the mollusc tissues and the mercury content in the near-bottom water layer and in bottom sediments (r from 0.68 to 0.92, p < 0.05). All studied species of molluscs are classified as macroconcentrators of mercury in water; Austriella corrugata can actively accumulate mercury not only from the water, but also from the bottom sediments. Bivalve molluscs can be used as an object of biomonitoring when studying the distribution of mercury in the estuary of the Red River.

Effect of the Concentration of Cations (Ca2+, Mg2+, Na+, and K+) in Water on the Level of Oxidative Processes in the Tissues of Bivalves of the Family Dreissenidae

The results of studying the influence of the content of Ca2+, Mg2+, Na+, and K+ cations in water on the level of lipid peroxidation products and antioxidants in the tissues of bivalve mollusks, D. bugensis and D. polymorpha, are presented. Mollusks were caught in four water areas of the Gorky Reservoir, which differ in the concentrations of Ca2+, Mg2+, Na+, and K+ cations. A correlation relationship has been established between the quantitative parameters of cations in water and the intensity of peroxide processes, on the one hand, and the level of general antioxidant activity in mollusk tissues, on the other. Statistically significant interspecific differences in the studied parameters have been recorded in mollusks from areas with an increased concentration of cations.

Determination of histamine levels in fresh fish using Near Infrared (NIR) technology

Fresh fish and fish products are highly perishable food. Development of fast, secure and non- destructive technique for estimation the presence and quantity of components which are related with safety of food products is of great interest for science but also and for the industry sector. Above-mentioned idea is the aim of this research work, precisely, determination of histamine levels in fresh fish with the use of different near infrared handheld devices. Histamine is one of biogenic amines among putrescine, cadaverine, tyramine which are non-volatile amines produced post mortem and are formed from decarboxylation of specific free amino acids in fish or shellfish tissue. Reason why we choose to developing technique for evaluation of histamine levels is EU Regulation 2073/2005 requires the determination of histamine at three different levels: 100, 200 and 400 mg/kg. For reaching the goal we decided to use paper-based technology for collecting samples for evaluation using Whatman grade 2 qualitative filter papers. In the first phase for validation of NIR devices specifications, and for creation of calibration curve we used histamine solution with 0.5, 1, 2.5 and 5 %. Results showed regression of R2 = 0.69 which indicates that NIR devices can be promising tools for spotting histamine beside small molecular weight.

Peculiarities of Transamination Processes in Tissues of Cyprinus carpio and Unio pictorum under the Impact of Elevated Concentrations of Metal Ions in Water

The role of the amino acids' transamination in the tissues of fish (<i>Cyprinus carpio</i> L.) and mollusk (<i>Unio pictorum</i> L.) in homeostasis of protein metabolism under the impact of 2 and 5 maximum permissible concentrations (MPC) of Mn<sup>2+</sup>, Zn<sup>2+</sup>, Cu<sup>2+</sup> and Pb<sup>2+</sup> ions was studied. Changes in the aspartate amino-transferase (AsAT) and alanine aminotransferase (AlAT) activity under toxic impact were species-specific and depend on nature and concentration of metal in water, tissular and cellular localization of enzymes. Impact of all metals, except for Cu, caused increase of mitochondrial AsAT activity in liver and muscles of carp. Exposure to sublethal concentrations of Zn<sup>2+</sup>, Cu<sup>2+</sup>, and Pb<sup>2+</sup> ions also resulted in AsAT activation in the mitochondria of mollusk's tissues. AlAT activity in the cytoplasmic fraction of muscles and liver of both hydrobionts increased under the impact 5 MPC of all metal ions and decreased under 2 MPC. Changes of AlAT activity in mitochondria and AsAT in cytoplasm of both fish and mollusk under the impact of 2 MPC were multidirectional and determined by metal and its concentration. The transaminases' role in adaptation of the aquatic animals to the impact of heavy metal ions consists in redistribution of amino acid reserves in order to use some for ammonia detoxification (glutamate, aspartate), and others (keto acids) for energy producing to counteract the stress factor. Changes in transaminases' activity reflect the state of the organism under the impact of elevated concentrations of heavy metal ions, characterize degree of the considered hydrobionts resistance to pollution, and can also be used to predict changes in biocenoses in the contaminated areas.

Proteomic analysis of hepatic effects of okadaic acid in HepaRG human liver cells.

The marine biotoxin okadaic acid (OA) is produced by dinoflagellates and enters the human food chain by accumulating in the fatty tissue of filter-feeding shellfish. Consumption of highly contaminated shellfish can lead to diarrheic shellfish poisoning. However, apart from the acute effects in the intestine, OA can also provoke toxic effects in the liver, as it is able to pass the intestinal barrier into the blood stream. However, molecular details of OA-induced hepatotoxicity are still insufficiently characterized, and especially at the proteomic level data are scarce. In this study, we used human HepaRG liver cells and exposed them to non-cytotoxic OA concentrations for 24 hours. Global changes in protein expression were analyzed using 2-dimensional gel electrophoresis in combination with mass-spectrometric protein identification. The results constitute the first proteomic analysis of OA effects in human liver cells and indicate, amongst others, that OA affects the energy homeostasis, induces oxidative stress, and induces cytoskeletal changes.

Активность основных дозообразуюших радио' нуклидов в водоемах белорусского сектора зоны Чернобыль' ской атомной электростанции и создаваемые ими дозовые нагрузки на биоту

In 2014-2015 we determined the activity of the most abundant radionuclides 90Sr, 137Cs and 241Am in the water column, bottom sediments and dominant species of macrophytes and mollusks in two water bodies of the Belarusian sector of the near zone of the Chernobyl nuclear power plant (ChNPP). Of these, the low-flowing Perstok Lake is the most contaminated with radionuclides water body in Belarus sector of ChNPP, and the flowing Borshchevska waterlogging, which has formed in the past two decades, is characterized by an average level of radiation contamination for the near zone of ChNPP. These data were used to calculate the values of the absorbed dose rate (ADR) during internal exposure for the dominant biota of water bodies from the indicated complex of radionuclides. In the bottom sediments of the Perstok Lake, the activity of 90Sr and 137Cs reached 185 and 468 kBq^m-2, respectively, and in the Borshchevska waterlogging, respectively 61 and 212 kBq^m-2, which significantly exceeds the pre-accident level. Among the biota organisms, macrophytes were characterized by the highest levels of the activity of 90Sr and 137Cs. In the Perstok Lake the values of 90Sr and 137Cs activities for them reached 24700 and 40100 Bq^kg-1 dry weight, respectively, and in the Borshchevska waterlogging -8747 and 3780 Bq^kg-1 dry weight. Among the mollusks of the Perstok Lake Anodonta spp. shells were characterized by the highest activities of 90Sr and 137Cs - up to 50216 and 1049 Bq^kg-1 of wet weight. The activity of 137Cs in the soft tissues of mollusks is much lower - no more than 780 Bq^kg-1 of live weight. The activity of 241Am in bottom sediments and macrophytes of the Perstok Lake during the study period was significantly lower - no more than 4.4 kBq^m-2 and 202 Bq^kg-1 of dry weight, and in the Borshchevska waterlogging - 2.6 kBq^m-2 and 48.1 Bq^kg-1 dry weight. 241Am activity in soft tissues and shells of mollusks from both reservoirs was not recorded in most cases. The total values of ADR from all the studied radionuclides in macrophytes and mollusks varied within 10-28 mkGyday-1, and in the mollusk of Lymnaea stagnalis - 64 mkGyday-1. The greatest contribution to the formation of the total ADR in macrophytes (within 42-99 %) and mollusks (up to 99 %) is made by the 90Sr + 90Y isobar. In most cases, the contributions of the 137Cs+137Ba and 241Am isobar to the total ADR values are extremely insignificant. Only for the roots of Typha angustifolia their contribution reached 37.7 and 20.3 %, respectively. Currently, in the near zone of ChNPP, against the background of a decrease in the activity of 90Sr and 137Cs, an increase in the activity of 241Am is observed. It is predicted that by the middle of the XXI century 241Am will become the main dose-forming radionuclide for the biota of water bodies in the near zone of the ChNPP.

Chemical status evaluation of the Romanian Black Sea marine environment based on benthic organisms’ contamination

The use of living organisms to provide information on the quality of aquatic environments is now a widely accepted methodology for assessing contaminant bioavailability. Molluscs have developed tolerance mechanisms towards environmental stressors and can accumulate a large range of contaminants. The assessment of marine environment quality was based on heavy metals (HM), persistent organic pollutants (organochlorine pesticides – OCPs and polychlorinated biphenyls - PCBs) and polynuclear aromatic hydrocarbons (PAHs) analysis in Mytilus galloprovincialis, Rapana venosa, Anadara kagoshimensis species sampled during 2016 - 2020 along Romanian Black Sea coast. Toxic metals (cadmium, lead) had bioaccumulation levels below threshold values in most molluscs samples investigated. Cadmium registered few values (15%) surpassing maximum admissible levels, in all three species. Data evaluation demonstrated the maintenance of a high level of concentrations of persistent organic pollutants in the mollusc tissue, but also of the exceedances of the values that characterize the good ecological status of these compounds. Polynuclear aromatic hydrocarbons showed a declining trend and no exceeding of the maximum allowed limit for benzo[a]pyrene was recorded in the last years. In consequence, the overview assessment based on “OneOutAllOut” (OOAO) approach, considering all groups of substances, indicates a bad chemical status for this period.

Ecological disturbances and abundance of anthropogenic pollutants in the aquatic ecosystem: Critical review of impact assessment on the aquatic animals

Anthropogenic toxins are discharged into the environment and distributed through a variety of environmental matrices. Trace contaminant detection and analysis has advanced dramatically in recent decades, necessitating further specialized technique development. These pollutants can be mobile and persistent in small amounts in the environment, and ecological receptors will interact with it. Despite the fact that few researches have been undertaken on invertebrate exposure, accumulation, and biological implications, it is apparent that a wide range of pollutants can accumulate in the tissues of aquatic insects, earthworms, amphipod crustaceans, and mollusks. Due to long-term stability during long-distance transit, a number of chemical and microbiological agents that were not previously deemed pollutants have been found in various environmental compartments. The uptake of such pollutants by the aquatic organism is done through the process of bioaccumulation when dangerous compounds accumulate in living beings while biomagnification is the process of a pollutant becoming more hazardous as it moves up the trophic chain. Organic and metal pollution harms animals of every species studied so far, from bacteria to phyla in between. The environmental protection agency says these poisons harm humans as well as a variety of aquatic organisms when the water quality is sacrificed in typical wastewater treatment systems. Contrary to popular belief, treated effluents discharged into aquatic bodies contain considerable levels of Anthropogenic contaminants. This evolution necessitates a more robust and recent advancement in the field of remediation and their techniques to completely discharge the various organic and inorganic contaminants.