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Metal contamination poses a significant threat to elasmobranchs, underscoring the need for targeted conservation approaches. The critically endangered Brazilian guitarfish, Pseudobatos horkelii , confronts an array of challenges, notably overexploitation, putting its survival at risk. Our study investigated the potential toxicity arising from arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) contamination across various adult guitarfish tissues from southeastern Brazil. Serological stress indicators, nutritional metabolites, and creatinine, an organ function marker, were also assessed, and Selenium (Se) levels were also investigated for possible protective effects. Our investigation unveiled significant correlations between metal concentrations and the determined physiological markers, shedding light on potential adverse effects. Remarkably, six correlations were indicative of how Hg and Pb negatively impact hepatic metabolite assimilation, while As was shown to influence renal phosphorus dynamics, Cd to affect rectal gland phosphorus regulation, and Pb to influence creatinine production in muscle tissue. Furthermore, Se demonstrated protective properties against Cd, Hg, and Pb, suggesting a role in alleviating the toxicity of these elements. Despite probable protective Se influences, the detected elemental interactions still suggest potential for organ impairment. These findings gain heightened significance within the context of the cumulative stressors faced by the Brazilian guitarfish, with metal contamination exhibiting the capacity to erode this species resilience against both anthropogenic and environmental pressures, thereby disrupting systemic equilibrium and jeopardizing wild populations. By investigating the intricate balance between metal accumulation and physiological consequences, our study contributes with crucial insights into potential conservation strategy formulations towards pollution for this critically endangered elasmobranch species. [Display omitted] • Physiological mechanism impairments were correlated with metal tissue accumulation. • As and Cd contamination potentially affects osmoregulation and enzymatic activity. • Pb contamination has the potential to compromise the integrity of muscle tissue. • Hg and Pb contamination in the liver impairs energy mobilization. • The protective effect of Se was not enough to prevent physiological alterations. [ABSTRACT FROM AUTHOR]

Metal contamination associated with mining activities has been considered one of the main environmental pollution problems in the Amazon region. Understanding the levels of metal contamination from mining activities requires a good understanding of background metal concentrations, which may vary notably according to the geology/lithology characteristics of the region, soil type, and predominant biogeochemical processes. This review assessed 50 papers and reports published between 1989 and 2020 describing environmental concentrations of different metals and metalloids (As, Hg, Mn, Fe, Cd, Cu, Cr, Pb, Ni, and Zn) in water and sediments of mining and non-mining areas in five geographic regions of the Amazon basin. Metal enrichment caused by mining activities was calculated and exposure concentrations were compared with sediment and water quality standards set for the protection of aquatic life. Significant enrichments of Cd, Cu, Cr, Fe, Hg, Mn, Ni and Zn were observed in mining areas in both sediment and water. Regarding background levels in the different geographic regions, the highest prevalence of metal enrichment (i.e., concentrations 10 to 100-fold higher than mean background values) in sediment samples was found for Fe (100% of samples), Ni (90%), and Mn (69%). For water, high prevalence of metal enrichment occurred for Zn, Mn, and Fe (100% of samples), and for Hg (86%). Hg, Fe, Pb, Cu, Cd, Ni and Zn exceeded water and/or sediment quality standards in a significant number of samples in the proximity of mining areas. This study indicates that mining activities significantly contribute to water and sediment contamination across the Amazon basin, posing hazards for freshwater ecosystems and potentially having human health implications. [Display omitted] • Background metal concentrations were evaluated in different Amazonian regions. • Cd, Cu, Cr, Fe, Hg, Mn, Ni and Zn were enriched in sediments and water of mining areas. • Hg, Fe, Pb, Cu, Cd, Ni and Zn exceeded water and/or sediment quality standards. • Metal contamination represents a threat for Amazonian freshwater ecosystems. [ABSTRACT FROM AUTHOR]

Mining areas may suffer long-term metal contamination and represent harmful remnants of former mining activities. In the northern Amazon of Ecuador, former mining waste pits are used in Oreochromis niloticus (Nile tilapia) fish farming. Given the high consumption of this species by the local population, we aimed to estimate human consumption risks by determining Cd, Cu, Cr, Pb, and Zn tissue bioaccumulation (liver, gills, and muscle) and genotoxicity (micronucleus essay) in tilapia cultivated in one former mining waste pit (S3) and compare the findings to tilapias reared in two non-mining areas (S1 and S2); 15 fish total. Tissue metal content was not significantly higher in S3 than in non-mining areas. Cu and Cd were higher in the gills of tilapias from S1 compared to the other study sites. Higher Cd and Zn were detected in the liver of tilapias from S1 compared to the other sampling sites. Cu was higher in the liver of fish from S1 and S2, and Cr, in the gills of fish from S1. The highest frequency of nuclear abnormalities was observed in fish from S3, indicating chronic exposure to metals at this sampling site. The consumption of fish reared at the three sampling sites results in a 200-fold higher Pb and Cd ingestion than their maximum tolerable intake thresholds. Calculated estimated weekly intakes (EWI), hazard quotients (THQ), and Carcinogenic Slope Factors (CSF ing) denote potential human health risks, indicating the need for continuous monitoring in this area to ensure food safety not only in areas affected by mining, but in general farms in the region. [Display omitted] • Cd, Cu, Cr, Pb, and Zn accumulation was detected in Tilapia reared in mining waste in non-mining areas in Ecuadorian Amazon. • High genotoxicity was detected in tilapia reared in mining waste. • Fish ingestion from all sampling sites leads to Pb and Cd ingestion 200-fold higher than maximum tolerable intake thresholds. • Potential human health risks due to tilapia consumption are noted. • Continuous monitoring is required to ensure food safety. [ABSTRACT FROM AUTHOR]

Few studies have examined the influence of reservoir hydrodynamics on the water quality of its limnological zones. In this study, the relationships between the operational phases and the water quality of the limnological zones were assessed for the Amazonian reservoir Tucuruí. Limnological zones were clustered by means of an artificial neural network technique, and inputs used were water quality variables, measured at twelve stations between 2006 and 2016. Generalized Linear Models (GLMs) were then used to identify the influence of the operational phases of the reservoir on the water quality of its limnological zones. The GLM with a gamma-distributed response variable indicated that Chlorophyll- a concentrations in the riverine and transitional zones differed notably from those observed in the lacustrine zone. Chlorophyll- a concentrations were significantly lower during the operational falling water phase than in the low water phase (p < 0.05). The GLM with an inverse Gaussian-distributed response variable indicated that Secchi depth was significantly lower in the riverine than in the lacustrine limnological zone (p < 0.05). Our results suggest that more eutrophic conditions occur during the operational rising water phase, and that the area most vulnerable to eutrophication is the transitional zone. We demonstrate that the use of GLMs is suitable for determining areas and operational phases most vulnerable to eutrophication. We envisage that this information will be useful to decision-makers when monitoring the water quality of hydroelectric reservoirs with dendritic patterns and dynamic operational phases. Image 1 • We assessed the water quality of a hydroelectric reservoir using ANN and GLMs. • Eutrophic conditions differ during operational phases and in each limnological zone. • Rising and high water were more eutrophic than low and falling operational phases. • The transitional zone is the most susceptible area to eutrophication. • This approach identifies areas and operational phases susceptible to eutrophication. [ABSTRACT FROM AUTHOR]

Cocaine and its primary metabolite, benzoylecgonine, have been recently detected in sharks, indicating a growing concern over marine drug pollution. The presence of this drug in marine fauna poses risks such as physiological stress, impaired growth, reproduction, and altered behaviors, potentially leading to biodiversity loss and disrupted ecological interactions. Biomagnification may further affect higher trophic levels, including humans. Addressing this issue requires continuous monitoring, studies on physiological effects, understanding contamination routes, and improving wastewater treatment. Additionally, stricter regulations on pharmaceutical disposal are necessary to mitigate the impacts of such pollutants on marine ecosystems and human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Pakistan, a country with limited water resources and highly vulnerable to the adverse effects of climate change, faces numerous challenges in managing its water supply. In this sense, this study assessed potentially toxic elements (PTEs) in the surface water and sediments of Pakistan's Indus River and its tributaries. Key water quality parameters such as pH, electrical conductivity (EC), and total dissolved solids (TDS) were determined, with respective average values of 7.1, 40 μS/cm, and 208 mg L -1 . The concentrations of Cd, Cr, Cu, Ni, and Zn in surface water samples averaged 26 μg L -1 , 0.9 μg L -1 , 1.4 μg L -1 , 22 μg L -1 , and 2.1 μg L -1 , respectively. The general sediment PTE profile was Ni > Cd > Zn > Cu > Cr. Certain PTE levels exceeded recommended thresholds, indicating the establishment of environmental pollution. Calculated geo-accumulation index values suggested moderate to heavy pollution levels in sediment, with PERI (404) values reinforcing the ecological risk posed by elevated PTE concentrations. Furthermore, significant correlations were observed between specific PTE pairs in both water and sediment samples. This study contributes with novel insights into the distribution and ecological implications of PTE contamination in the Indus River and its tributaries, paving the way for ecological risk management efforts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The potential negative impacts of Technology-Critical Elements (TCEs) on the environment and wildlife, despite increasingly recognized, remain largely overlooked. In this sense, this study aimed to investigate the concentrations of several TCEs, including rubidium (Rb), titanium (Ti) and various Rare Earth Elements (REEs), in different tissues of tiger sharks. Sharks incidentally caught by artisanal fleets in southern Brazil were opportunistically sampled and liver, gills, kidneys, heart, muscle, eyes, brain, skin, and teeth were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Significant Rb concentration variations were observed across different tissues, with higher levels detected in kidneys and lower levels in the liver. Titanium concentrations also exhibited significant differences, with higher levels detected in teeth and lower levels in liver. Although no statistical differences were observed for the analyzed REEs, a trend of higher accumulation in the liver, gills, and skin was noted. Light Rare Earth Elements (LREEs) were found predominantly in all organs, with neodymium, lanthanum, and cerium as the most significant REEs detected. Several statistically significant correlations were identified between Rb and REEs, as well as between Ti and REEs, indicating systemic transport of these elements across different tissues. These findings indicate that the growing extraction and disposal of metallic elements, driven by technological advancements, may lead to their assimilation by marine fauna, particularly at higher trophic levels. The potential harmful effects on these organisms remain unknown and require urgent investigation. Additionally, as mining activities intensify globally, precise legislative measures are essential to address environmental concerns, species conservation, and human health considerations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Subcellular metal distribution assessments are the most adequate biomonitoring approach to evaluate metal toxicity, instead of total metal assessments This study aimed to assess subcellular metal distributions and associations to the main metal exposure biomarker, metallothionein (MT), in two bromeliad species (Tillandsia usneoides and Tillandsia stricta) exposed established in industrial, urban, and port areas in the metropolitan region of Rio de Janeiro, southeastern Brazil, through an active biomonitoring approach conducted one year. Metals and metalloids in three subcellular fractions (insoluble, thermolabile and thermostable) obtained from the MT purification process were determined by inductively coupled plasma mass spectrometry (ICP-MS). Lower MT concentrations were observed both during the dry sampling periods, associated to the crassulacean acid metabolism (CAM) and during the COVID-19 pandemic, due to reduced urban mobility, decreasing pollutant emissions. The percentage of non-bioavailable metals detected in the insoluble fraction increased throughout the sampling period for both species. Several metals (Cr, Co, Cu, Cd, Mn, Ni, Se, and Zn), most associated with vehicle emissions, the main pollutant source in urban centers, were detected in the thermostable fraction and are, thus, associated with MT through the MT-metal detoxification route. Insoluble metal concentrations were higher in T. stricta, indicating that this species seems less susceptible to cellular metal exposure damage. A potential protective effect of Se and Fe was detected against Pb, suggested by a strong negative correlation, which may be attributed to antioxidant roles and similar uptake routes, respectively., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

A mining tailing dam rupture in Brazil in November 2015 released millions of tons of mining waste into the Rio Doce ecosystem, leading to long-term aquatic ecosystem impacts. Although multiple lines of evidence indicate tailings associations with potentially toxic elements in estuarine sediments and biological impact and bioaccumulation pathways in fishes, the extent of contamination in base benthic species is still largely unknown. Moreover, Rare Earth Elements (REE) have not received any attention in this regard. This study assessed REE in fiddler crabs (Minuca rapax) sampled from the Rio Doce estuary in 2017, nearly 2 years after the disaster. The ΣREE in crab hepatopancreas and muscle were high (327.83 mg kg -1 w.w. and 33.84 mg kg -1 w.w., respectively, compared to other assessments in crabs, indicating a preference for REE bioaccumulation in the hepatopancreas compared to muscle. Neodimium, La, and Ce were detected at the highest concentrations. The REE from the Rio Doce Basin were, thus, transported and deposited in the estuary with the mine tailings slurry, leading to bioaccumulation in crabs. This may lead to trophic effects and other ecological impacts not readily measured by typical impact assessment studies, revealing an invisible and not typically acknowledged damage to the Rio Doce estuary., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

A large-scale oil spill along the northeastern Brazilian coast in 2019-2020 severely impacted primary manatee habitats in Brazil. This study aimed to assess metal and metalloid contamination in a dead manatee calf found following this oil spill. Several elements were detected, including chromium, iron, nickel, lead, and vanadium, which are crude oil components, and thallium, a component of dispersants used to degrade and dissipate crude oil. The presence of these contaminants in the manatee calf is indicative of maternal exposure, metabolism, and newborn transference via placenta and lactation. This is the first report of mother-calf metal transfer in manatees, highlighting the species' vulnerability and potential long-term population dynamics effects, and the first report for several metals and metalloids in these animals, laying the foundation for future research efforts. These findings highlight the urgent need for continued environmental monitoring, ecotoxicological assessments, and conservation initiatives., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Sponges are not routinely employed as metal bioindicators in Brazil. In this sense, this study reports baseline metal and metalloid concentrations, determined by inductively coupled plasma mass spectrometry, for two Demospongiae sponge species, Hymeniacidon heliophila and Desmapsamma anchorata, sampled from two Southeastern Brazil areas. Sponges from Ilha Grande Bay, an Environmental Protection Area, exhibited higher Al, As, Cd, Co, Cr, Fe, and Ni levels compared to Vermelha Beach, a metropolitan area in the Rio de Janeiro city. Several strong correlations were noted between elemental pairs, indicating common contamination sources and/or similar metabolic detoxification routes. Comparisons of the means determined herein for each study site to other reports indicate mostly lower Ag, As, Co, Cd, and Cu levels, while Al levels were higher than other studies, and Cr, Ni, and Fe were within reported ranges. These baseline data further knowledge on metal pollution in Desmspongiae members, which are still limited., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Endocrine Disrupting Chemicals (EDCs) encompass a wide variety of substances capable of interfering with the endocrine system, including but not limited to bisphenol A, organochlorines, polybrominated flame retardants, alkylphenols and phthalates. These compounds are widely produced and used in everyday modern life and have increasingly been detected in aquatic matrices worldwide. In this context, this study aimed to carry out a literature review to assess the evolution of EDCs detected in different matrices in the last thirty years. A bibliometric analysis was conducted at the Scopus, Web of Science, and Google Scholar databases. Data were evaluated using the Vosviewer 1.6.17 software. A total of 3951 articles in English were retrieved following filtering. The results demonstrate a gradual and significant growth in the number of published documents, strongly associated with the increasing knowledge on the real environmental impacts of these compounds. Studied were mostly conducted by developed countries in the first two decades, 1993 to 2012, but in the last decade (2013 to 2022), an exponential leap in the number of publications by countries such as China and an advance in research by developing countries, such as Brazil, was verified., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

In September 2020, a male common dolphin (Delphinus delphis) was found dead on a beach near Bat-Yam, Israel. A small, raised, well circumscribed penile lesion (i.e., mass) was identified and removed for histology and molecular characterizations. By histology, the penile mass presented focal keratinization of the squamous epithelium and a mild ballooning of acanthocytes in lower epithelium levels, as well as features compatible with viral plaques, and tested positive for a gammaherpesvirus through molecular characterization analyses. Tissue samples from the lungs, liver, and spleen, however, tested negative for herpesvirus infection. The gammaherpesvirus detected herein is similar to other isolates found in several areas worldwide in different cetacean species. This is the first reported case of gammaherpesvirus infection in dolphins from the eastern Mediterranean Sea, indicative of the need for long-term assessments to create viral infections databases in cetaceans, especially in a climate change context, which is likely to intensify infectious disease outbreaks in marine mammals in the future., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Yeast infections have gained significant attention in the field of marine biology in recent years. Among the broad diversity of marine organisms affected by these infections, elasmobranchs (sharks and rays) have emerged as highly susceptible, due to climate change effects, such as increasing water temperatures and pollution, which can alter the composition and abundance of fungal communities. Additionally, injuries, or compromised immune systems resulting from pollution or disease may increase the likelihood of fungal infections in elasmobranchs. Studies are, however, still lacking for this taxonomic group. In this context, this study aimed to screen yeast species in cell cultures obtained from the brain of artisanally captured Pseudobatos horkelii, a cartilaginous fish that, although endangered, is highly captured and consumed worldwide. Fungi were isolated during an attempt to establish primary cultures of elasmobranch neural cells. Culture flasks were swabbed and investigated using morphological, phenotypic, and molecular techniques. Two isolates of the emerging opportunistic pathogen Trichosporon japonicum were identified, with high scores (1.80 and 1.85, respectively) by the MALDI-ToF technique. This is the first report of the basidiomycetous yeast T. japonicum in Pseudobatos horkelii in Brazil. This finding highlights the need for further research to determine the potential impact on elasmobranch health, ecology, as well as on commercial fisheries., (© 2023. The Author(s).)

Polycyclic aromatic hydrocarbon (PAH) contamination is ubiquitous and comprises a significant worldwide concern in ecological and Public Health frameworks. Many aquatic biota representatives have been reported as contaminated by these toxic compounds, including one of the most threatened vertebrate groups, elasmobranchs (sharks and rays). Although elasmobranchs play important ecological roles and provide significant ecosystem services, they are highly consumed and comprise a cheap source of protein for humans globally. Studies concerning elasmobranch PAH contamination are, however, notably lacking. A systematic review was, thus, conducted herein to assess PAH elasmobranch contamination and discuss potential human health risks following the Preferred Reporting Item Statement Guidelines for Systematic Reviews and Meta-analyses (PRISMA) guidelines applying the Population (P), Intervention (I), Comparison I, and Outcome (O) (PICO) strategy. A total of 86 published papers were retrieved by this method and analyzed. Only nine studies of this total concerned PAH elasmobranch contamination, assessed in 10 shark species and one ray species, with only one study calculating human health risks. A significant knowledge gap is, thus, noted for this subject, indicating the need to monitor PAH elasmobranch contamination in consumed shark and ray species worldwide., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The current climate change scenario caused by anthropogenic activities has resulted in novel environmental pressures, increasing the occurrence and severity of fungal infections in the marine environment. Research on fungi in several taxonomic groups is widespread although not the case for elasmobranchs (sharks and rays). In this context, the aim of the present study was to screen the oral fungal microbiota present in artisanally captured Rioraja agassizii , a batoid that, although endangered, is highly fished and consumed worldwide. Oropharyngeal samples were obtained by swabbing and the samples were investigated using morphological and phenotypic methods by streaking on Sabouraud Dextrose Agar (SDA) and subculturing onto CHROMagar Candida (BD Difco) and CHROMagar Candida Plus (CHROMagar TM ), as well as molecular techniques by amplification of the ITS1-5.8S-ITS2 ribosomal DNA region and a MALDI-TOF MS assessment. The findings indicated the presence of Candida parapsilosis (seven isolates), Candida duobushaemulonii (one isolate) and Rhodotorula mucilaginosa (three isolates), several of these reported for the first time in Rioraja agassizii . In addition, a 100% agreement between the MALDI-TOF results and partial ITS region sequencing was noted, demonstrating that the MALDI-TOF MS is a rapid and effective alternative for yeast identification in Rioraja agassizii isolates and potentially in other elasmobranch species. These findings highlight the need for further research to determine the potential impact on elasmobranch health, ecology, and commercial fisheries. Furthermore, this research is paramount in a One Health framework and may be employed to predict elasmobranch responses to an evolving ocean, keep healthy populations in check, monitor species, and assess the public health consequences of consuming these species.

Organochlorine pesticides (OCP) are legacy anthropogenic compounds known to persist for several years in the environment. The continuous use of some OCP, such as DDT, after restrictions in developing countries are cause of concern, due to their deleterious effects to marine life and humans. Studies assessing OCP contamination in coastal environments are still scarce in South America and there is a need to understand the impacts from trophic chain accumulation of these pollutants in marine life. In this study, we have assessed OCP levels in muscle and liver and estimated the biomagnification factor in several upwelling system trophic chain members, including fish, squid, and marine mammal from Southeastern Brazil. DDT degradation product DDE was the OCP detected in the highest concentrations in Franciscana dolphins ( Pontoporia blainvillei ), 86.4 ng·g -1 wet weight, and fish muscle and liver. In general, higher OCP levels were found in liver than in muscle, except for croaker. Biomagnification factors (BMF) of OCP in the top predator P. blainvillei and the carnivorous cutlass fish ( Trichiurus lepturus ) were on average between 0.2 and 1.8. Continued OCP monitoring in this region is warranted to better understand the distribution and fate of these compounds over time, with the goal to establish strategies for the conservation of local dolphin species and to assess human health risks from local coastal region populations.

Cortisol is the main glucocorticoid released during stress responses in most fish and has been employed to investigate different stressors, including organic pollutants. This review discusses shifts in cortisol concentrations and examines different matrix sampling methods (invasive vs. minimally or non-invasive) and the main analytical cortisol determination techniques (immunoassays and liquid chromatography-tandem mass spectrometry). Assessments on organic pollutant exposure in fish and associated adverse effects are also discussed. Studies in this regard may aid in identifying organic pollutant toxicological modes of action, mechanistic response, toxicokinetics, and toxicodynamics, as well as pollution sources and associated health risks in fish, ultimately aiding in the development of effective management strategies to mitigate the impacts of organic pollutants on fish populations and their associated ecosystems.

Shark assessments in the Mediterranean Sea are still scarce, and serum chemistry and haematological data have yet to be reported for wild dusky ( Carcharhinus obscurus ) or sandbar ( Carcharhinus plumbeus ) shark populations in the Mediterranean Sea. Herein, blood samples were obtained from adult dusky ( n  = 23) and sandbar ( n  = 14) sharks from an aggregation site near the Hadera power and desalination plants in Israel in the winters of 2016-20. Several serum chemistry analytes were characterized with relation to stress, body size and environmental conditions. Glucose concentrations were higher, while total cholesterol concentrations were lower in dusky sharks than in sandbar sharks, potentially due to distinct metabolic pathways utilized during the capture-related activity by both species. However, differences in sex and size are noted and should be considered. The blood cell morphology of both species was consistent with previous findings for sandbar sharks. Atypical monocytes were noted in one dusky shark. Preliminary and exploratory reference intervals for female dusky sharks were calculated for glucose, triglycerides, total cholesterol, total protein and creatine kinase. These data must be viewed with caution due to the potential influence of capture-related stress on analyte concentrations and activities and the fact that only females were employed in the calculations. Moreover, the sampling site is adjacent to coastal power and desalination plants, which may significantly affect shark physiology. Although limited, this novel database on dusky and sandbar shark serum chemistry and haematology aspects is essential as a first attempt to obtain data on these species in the eastern Mediterranean Sea and for future conservation and long-term biomonitoring efforts., (© The Author(s) 2023. Published by Oxford University Press and the Society for Experimental Biology.)

Metal and metalloid concentrations in Black Triggerfish, Melichthys niger (Tetraodontiformes, Balistidae), and sediments from Trindade Island, an isolated, pristine, and understudied environment in the Southwestern Atlantic Ocean were determined. Several elements were detected in sediment, including Rare Earth Elements (REE). Hg and the REE Nd were, however, not detected. Elements determined in triggerfish are indicative of systemic circulation and the presence of toxic elements indicates an exposure source. No significant associations were detected between elements in fish organs and total length, suggesting no bioaccumulation with age, nor between organs and sediment, indicating probable dietary origin. Biliary excretion indicated a local chronic source of As and Cd and non-quantifiable REE elimination. Hg concentrations were over thresholds that affect fish biochemistry processes. These baseline data are valuable concerning elemental contamination in remote oceanic islands, with the potential to be applied to future biomonitoring efforts and conservation measures for reef ecosystems worldwide., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The tiger shark ( Galeocerdo cuvier ) has been relatively well assessed concerning biology and ecology aspects in both Atlantic and Pacific North America and in Caribbean waters. The amount of data in these regions has led to the species protection under capture quotas and with the creation of sanctuaries. The reality in developing countries, however, is the exact opposite, with scarce information on the species in the southern hemisphere, namely South American and African waters. In these regions, protection measures are insufficient, and studies on tiger shark biology and ecology are scarce, significantly hindering conservation and management efforts. Thus, the aim of this study was to compile scientific literature on the tiger shark in the South Atlantic and discuss the impact of these data (or lack thereof) distributed within a total of ten research categories for guiding management plans. In total, 41 scientific publications on different G. cuvier biology and ecology aspects were obtained. The most studied topics were Feeding Ecology ( n = 12), followed by Human Interactions ( n = 8), and Movements and Migration ( n = 7). Northeastern Brazil (Southwest Atlantic) was the most researched area, probably due to the higher coastal abundance of tiger sharks in this area, alongside a high number of recorded attacks, justifying funding for studies in the region. No studies carried out in other South American or African countries were found. It is important to mention that even though some research topics are relatively well covered, a severe knowledge gap is noted for risk assessments and fisheries management, with a proposition for the implementation of sanctuaries noted. This is, however, particularly worrisome, as the South Atlantic is mostly unexplored in this regard for tiger sharks. It is also important to note how different the attention given to this species is in the North Atlantic when compared to the South region. Lastly, we highlight that the existence of sub-populations, the lack of migratory corridors geographically connecting distinct areas used by the species, and the lack of fisheries statistics on tiger shark landings, all increase the vulnerability of this species in the South Atlantic., Competing Interests: Rachel Ann Hauser-Davis is an Academic Editor at PeerJ., (© 2023 Balanin et al.)

Several diseases have been reported as affecting endangered wild sea turtle population worldwide, including spirorchiidiasis. This parasitic infection results in serious circulatory disorders in sea turtles, as well as tissue damage due to the presence of spirorchiids eggs. However, few reports of organs severely affected by tissue replacement caused by granulomatous inflammatory processes due to spirorchiidiasis in sea turtles are available. In this regard, this study describes massive lesions in 16 juvenile green turtles from southeastern Brazil presenting no other detectable diseases or injuries, associated to parasitic compression of air spaces, parasitic thyroid atrophy, parasitic encephalic compression and parasitic splenic lymphoid depletion. These rare injuries were categorized as extremely severe, affecting most spirorchiidiasis-infected organs. Spirorchiidiasis was, thus, noted herein as capable of causing a variety of lethal injuries to vital or extremely important organs in sea turtles. Spirorchiidiasis should, therefore, also be considered a potential cause of death in stranded green sea turtle monitoring efforts., Competing Interests: None., (© 2023 The Authors.)

The final disposal of municipal solid waste (MSW) in dumpsites is still a reality worldwide, especially in low- and middle-income countries, leading to leachate-contaminated zones. Therefore, the aim of this study was to carry out soil and leachate physicochemical, microbiological, and toxicological characterizations from a non-operational dumpsite. The L-01 pond samples presented the highest physicochemical parameters, especially chloride (Cl; 4101 ± 44.8 mg L -1 ), electrical conductivity (EC; 10,452 ± 0.1 mS cm -1 ), and chemical oxygen demand (COD; 760 ± 6.6 mg L -1 ) indicating the presence of leachate, explained by its close proximity to the landfill cell. Pond L-03 presented higher parameters compared to pond L-02, except for N-ammoniacal and phosphorus levels, explained by the local geological configuration, configured as a slope from the landfill cell towards L-03. Seven filamentous and/or yeast fungi genera were identified, including the opportunistic pathogenic fungi Candida krusei (4 CFU) in an outcrop sample. Regarding soil samples, Br, Se, and I were present at high concentrations leading to high soil contamination (CF ≤ 6). Pond L-02 presented the highest CF for Br (18.14 ± 18.41 mg kg -1 ) and I (10.63 ± 3.66 mg kg -1 ), while pond L-03 presented the highest CF for Se (7.60 ± 1.33 mg kg -1 ). The most severe lethal effect for Artemia salina was observed for L-03 samples (LC 50 : 79.91%), while only samples from L-01 were toxic to Danio rerio (LC 50 : 32.99%). The highest lethality for Eisenia andrei was observed for L-02 samples (LC 50 : 50.30%). The applied risk characterization indicates high risk of all proposed scenarios for both aquatic (RQ 375-909) and terrestrial environments (RQ > 1.4 × 10 5 ). These findings indicate that the investigated dumpsite is contaminated by both leachate and metals, high risks to living organisms and adjacent water resources, also potentially affecting human health., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Guanabara Bay (GB) is a highly contaminated estuarine system and an important fishing area in Southeastern Brazil. In this regard, knowledge concerning the association of certain contaminants in seafood to abiotic factors and human health risk assessments is still understudied. Therefore, this study aimed to quantify nine toxic elements in highly consumed crabs, shrimp, and squid, and associate the results with abiotic factors. A human health risk assessment was also performed. Our findings indicate that crabs are the main bioaccumulators. Transparency and depth were noteworthy for all three taxonomic groups. In general, contaminant concentrations were below the limits established by different international agencies, except for As, which was higher than the Brazilian limit (1 mg kg -1 ). However, the Hazard Index identified risks to consumer health for the ingestion of seafood. This study emphasizes the importance of jointly evaluating different toxic elements, for a more accurate health risk assessment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

A screening for microcontaminants performed by gas chromatography detected several microcontaminants in 12 sediment samples from the eutrophic estuary Guanabara Bay (GB) in southeastern Brazil. Bisphenol A (BPA) ranged from 1.4 to 20.3 ng g -1 , 4-octylphenol, from -1 , 4-nonylphenol, from -1 , gemfibrozil, from -1 , naproxen, from -1 m Ibuprofen, from -1 and diclofenac, from -1 . Among estrogens, estrone, estradiol, ethinylestradiol and estriol were detected, ranging, respectively from -1 , -1 , -1 and -1 . A strong and positive correlation between 4-nonylphenol and estrone and a moderate and positive correlation between bisphenol A and estradiol were noted. These findings demonstrating high levels of the detected microcontaminants in all analyzed samples, indicating chronic GB pollution., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)

This study comprises a novel report on subcellular metal partitioning and metallothionein (MT) metal detoxification efforts in lesser numbfish (Narcine brasiliensis) electric ray specimens, as well as the first assessment on MT contents in any ray electric organ. Individuals sampled from an area in Southeastern Brazil affected by the Mariana dam rupture disaster were assessed concerning subcellular metal partitioning and MT metal-detoxification in the liver, gonads, electric organ and muscle of both adults and embryos. Yolk was also assessed when available. Relative total and heat-stable (bioavailable) metal and metalloid comparisons between adults and embryos in different developmental stages demonstrates maternal transfer of both total and bioavailable metals and significant MT associations demonstrate the detoxification of As, Ag, Mn, Ni, Cd, Co, Cu, Se and V through this biochemical pathway. Our findings expand the lacking ecotoxicological assessments for this near-threatened species and indicates significant ecological concerns, warranting further biomonitoring efforts., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Southern elephant seal (SES) and Antarctic fur seal (AFS) are short Southern Ocean food web top predators and are spatial and temporal trend bioindicators of Antarctic Hg bioavailability. Hg, stable isotope composition (δ 13 C and δ 15 N) and trophic position (TP) regarding sex were determined using lanugo samples from Antarctic pinnipeds pups (SES n = 35 and AFS n = 11). Hg concentrations in over 50% of the SES pups (mean 5.9 ± 3.1 mg kg -1 dry wt.) are compatible with those found to cause neurologic damage to polar bears in the Arctic. No significant differences regarding sexes for SES or AFS are found based on mean Hg concentrations normalized by body weight. δ 15 N values and TPs are similar among both species, indicating that gestating SES and AFS mothers feed at the same trophic level. Significantly different δ 13 C values were found, indicating distinct feeding grounds for mothers belonging to both species when pup lanugo is formed in utero; while SES females like to feed in Antarctic waters, AFS females remain in sub-Antarctic waters. The differences in Hg and δ 13 C observed for both species reflect not only contrasting feeding habits and anthropogenic Hg inputs, but also maternal foraging strategies., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Metals, many of which are potentially toxic, are present in the aquatic environment originated from both natural and anthropogenic sources. In these ecosystems, these elements are mostly deposited in the sediment, followed by water dissolution, potentially contaminating resident biota. Among several aquatic animals, crustaceans are considered excellent bioindicators, as they live in close contact with contaminated sediment. The accumulation of metal, whether they are classified as essential, when in excessive quantities or nonessential, not only cause damage to the health of these animals, but also to the man who consumes seafood. Among the main toxic elements to animal and human health are aluminum, arsenic, cadmium, chromium, copper, lead, mercury, nickel and silver. In this context, this systematic review aimed to investigate the dynamics of these metals in water, the main bioaccumulative tissues in crustaceans, the effects of these contaminants on animal and human health, and the regulatory limits for these metals worldwide. A total of 91 articles were selected for this review, and an additional 68 articles not found in the three assessed databases were considered essential and included, totaling 159 articles published between 2010 and 2020. Our results indicate that both chemical speciation and abiotic factors such as pH, oxygen and salinity in aquatic environments affect element bioavailability, dynamics, and toxicity. Among crustaceans, crabs are considered the main bioindicator biological system, with the hepatopancreas appearing as the main bioaccumulator organ. Studies indicate that exposure to these elements may result in nervous, respiratory, and reproductive system effects in both animals and humans. Finally, many studies indicate that the concentrations of these elements in crustaceans intended for human consumption exceed limits established by international organizations, both with regard to seafood metal contents and well as daily, weekly, or monthly intake limits set for humans, indicating consumer health risks., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Perna perna mussels, abundant throughout the Brazilian coast, are routinely applied as bioindicators in environmental monitoring actions due to their sessile and filter-feeding characteristics. In addition, they are noteworthy for their food importance, especially for coastal populations. In this context, the aim of this study was to investigate elemental contamination in commercially marketed and highly consumed P. perna samples from the highly impacted Guanabara Bay, Rio de Janeiro, Brazil. A total of 30 mussels were sampled, and elemental concentrations (As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn) were determined in adductor muscle samples by inductively coupled plasma mass spectrometry (ICP-MS). Human consumption risks were assessed by comparisons to Brazilian and international legislations. No significant differences between sex were observed for all analyzed elements. Even when analyzing only the adductor muscle, all mussel samples exceeded the Brazilian limit for Cr, while 12 samples exceeded the limit for Se. When compared to other regulatory agencies, As and Zn levels were higher than the limits set by China, New Zealand, and the USA. Estimated daily dietary intake values were not above limits imposed by the Food and Agriculture Organization of the United Nations/World Health Organization for any of the assessed elements, although it is important to note that only the adductor muscle was assessed. Therefore, continuous metal and metalloid monitoring in bivalves in the study region is suggested, as metal transport and bioavailability, especially in coastal estuaries such as Guanabara Bay, which are currently undergoing significant changes due to anthropogenic activities., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.)

A female Cuvier's Beaked Whale ( Ziphius cavirostris ) specimen measuring 580 cm in length died after being stranded in Southeastern Brazil. Following a necropsy, organ samples were obtained, fixed in 10% neutral buffered formalin and histopathologically analyzed. A severe and generalized hypodermis infection by Phyllobothrium delphini (Phyllobothriidae) was observed, resulting in granulomatous panniculitis. Severe renal and arterial lesions were also noted, including a severe bone metaplasia in the aorta artery, associated with a massive infection by Crassicauda sp, (Tetrameridae). A significant thoracic hemorrhage due to thoracic aorta artery rupture was noted, also likely due to this infection, resulting in a fatal injury. This study contributes towards knowledge on histopathologic changes in the scarcely studied Cuvier's Beaked Whale, is the first to associate a Crassicauda sp. infection in this whale species in the Brazilian region and also the first to indicate a resulting osseous metaplasia due to this parasitism and granulomatous dermatitis associated with Phyllobothrium delphini . Furthermore, this is also, to the best of our knowledge, the first report of Phyllobothrium delphini cysts in a Ziphius cavirostris specimen to date., Competing Interests: None., (© 2021 The Authors.)

Background: Elasmobranchs are particularly vulnerable to environmental metal contamination, accumulating these contaminants at high rates and excreting them slowly. The blue shark Prionace glauca L. is one of the most heavily fished elasmobranchs, although information regarding metal contamination and detoxification in this species is notably lacking., Methods: Blue sharks were sampled in the western North Atlantic Ocean, in offshore waters adjacent to Cape Cod, Massachusetts. Total and metallothionein-bound liver and muscle metal concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS), metallothionein detoxification and oxidative stress endpoints were determined by UV-vis spectrophotometry., Results: Metallothionein detoxification occurred for As, Cd, Cs, Cu, Hg, Pb, Se, Ti and Zn in liver, and for As, Cd, Cs, Pb, Se, and Zn in muscle, while reduced glutathione defenses seem to be related to Co and Zn exposure., Conclusion: This is the first report for several metals (Ag, Co, non-radioactive Cs, Sb, Ti and V) for this species, which will aid in establishing baseline elemental data for biomonitoring efforts, health metrics, and conservation measures., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

It is estimated that approximately 0.4% of the total leachate produced in a landfill is destined for treatment plants, while the rest can reach the soil and groundwater. In this context, this study aimed to perform leachate toxicity evaluations through immune system cytotoxic assessments, genotoxic (comet assay) appraisals and antioxidant system (superoxide dismutase - SOD; catalase - CAT, glutathione-S-transferase - GST; reduced glutathione - GSH and metallothionein - MT) evaluations in Eisenia andrei earthworms exposed to a Brazilian leachate for 77 days. The leachate sample contained high organic matter (COD - 10,630 mg L -1 ) and ammoniacal nitrogen (2398 mg L -1 ), as well as several metals, including Ca, Cr, Fe, Mg, Ni and Zn. Leachate exposure resulted in SOD activity alterations and increased CAT activity and MT levels. Decreased GST activity and GSH levels were also observed. Antioxidant system alterations due to leachate exposure led to increased malondialdehyde levels as a result of lipid peroxidation after the 77 day-exposure. An inflammatory process was also observed in exposed earthworms, evidenced by increased amoebocyte density, and DNA damage was also noted. This study demonstrates for the first time that sublethal effect assessments in leachate-exposed earthworms comprise an important tool for solid waste management., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Fish bile has been applied as a biomarker for environmental contamination for several decades, and several pollutants are known to be excreted in this matrix. With the advent of the proteomic field, however, the discovery of protein biomarkers of response to pollutants has become the highlight, and fish bile shows very high potential in this regard. A proteomic case study carried out in Southeastern Brazil with mullet bile indicates the importance of assessing bile colour, as different feeding statuses lead to differential proteomic profiles as observed by 2D SDS-PAGE analyses. In addition, several heat-stable proteins displaying a differential gel profile were also observed in tilapia bile when compared a contaminated and reference site. Therefore, the bile proteome displays the potential to offer a more sensitive and informative method to analyse the presence and effects of contaminants in aquatic ecosystems., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.)

Contamination by metals is among the most pervasive anthropogenic threats to the environment. Despite the ecological importance of marine apex predators, the potential negative impacts of metal bioaccumulation and biomagnification on the health of higher trophic level species remains unclear. To date, most toxicology studies in sharks have focused on measuring metal concentrations in muscle tissues associating human consumption and food safety, without further investigating potential impacts on shark health. To help address this knowledge gap, the present study evaluated metal concentrations in the gills, muscle, liver and rectal gland of coastal sharks opportunistically sampled from Brazilian waters and tested for potential relationships between metal bioaccumulation and general shark health and homeostatic balance metrics. Results revealed high metal concentrations in all four tissue types, with levels varying in relation to size, sex, and life-stage. Metal concentrations were also associated with serum biomarkers (urea, lactate, ALT, triglycerides, alkaline phosphatase, and phosphorus) and body condition, suggesting potential negative impacts on organismal health., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Lipids are excellent biomarkers for assessing coral stress, although staghorn coral data (Acropora cervicornis) is lacking. Lipid extraction is the most critical step in lipidomic assessments, usually performed using carcinogenic solvents. Efficient alternative using less toxic methods, such as the BUME method using butanol and methanol as extraction solvents, have not been applied to coral lipidomics evaluations. Thus, we aimed to develop a lipidomic approach to identify important coral health biomarkers by comparing different solvent mixtures in staghorn corals. Total lipid extraction was equivalent for both tested methods, but due to its efficiency in extracting polar lipids, the BUME method was chosen. It was then applied to different coral masses (0.33-1.00 g), resulting in non-significant differences concerning number of lipid classes and compounds. Therefore, this method can be successfully applied to coral assessments in a climate change context, with the added benefit of low sample masses, lessening coral sampling impacts., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.)

The current coronavirus pandemic is leading to significant impacts on the planet, changing our way of life. Although the COVID-19 virus mechanisms of action and pathogenesis are still under extensive research, immune system effects are evident, leading, in many cases, to respiratory distress. Although apparent pollution reduction has been noticed by the population, environmental and human health impacts due to the increased use of plastic waste and disinfectants is concerning. One of the main routes of human exposure to pollutants is through drinking water. Thus, this point of view discusses some major contaminants in drinking water known to be immunotoxic, exploring sources and drinking water routes and emphasizing the known mechanisms of action that could likely compromise the effective immune response of humans, particularly raising concerns regarding people exposed to the COVID-19 virus. Based on a literature review, metals, plastic components, plasticizers, and per- and polyfluoroalkyl substances may display the potential to exacerbate COVID-19 respiratory symptoms, although epidemiological studies are still required to confirm the synergistic effects between these pollutants and the virus.

Although significantly impacted, Guanabara Bay (GB), located in southeastern Brazil, is still an important fishery source for the state of Rio de Janeiro. Hg contamination, in particular, is of concern in the area and should be regularly monitored, as Hg bioaccumulation and biomagnification processes may lead public health risks to the local human population due to the consumption of contaminated food items, such as crabs. In this context, the aim of the present study was to determine total Hg (THg) concentrations in swimming crabs from three GB areas and investigate the influence of biotic and abiotic factors on Hg concentrations at the beginning and the end of the rainy season. Crabs and water samples were obtained from three areas, inside the bay, at the mouth of the bay and outside the bay. A clear rainfall effect on the investigated abiotic variables was observed, with increased rainfall and temperatures noted at the end of the study period. Significant statistical correlations were observed between THg concentrations and the assessed abiotic variables at the three study points at the beginning and end of the rainy season. The rainy season was noted as directly affecting THg concentrations at Guanabara Bay and, consequently, swimming crab THg contents. THg concentrations in swimming crabs at Urca and at the Cagarras Islands were higher at the beginning of the rainy season compared to the end, while the opposite was observed for the sampling point outside the bay. Higher Hg concentrations were detected at the outermost point of the bay in relation to the Cagarras Islands, probably due to the local upwelling event. THg values in Callinectes sp. were higher than concentrations reported for other areas in Brazil but lower than other reports worldwide. Calculated THg intakes surpassed the maximum National Research Council permissible limits of 0.049 mg/week at all sampling stations during both seasons, raising public health concerns. Further research for longer monitoring periods during different seasons are essential to ascertain which climatic period is most critical regarding Hg availability at this anthropogenically-impacted estuary.

The aim of the present study consisted in evaluating the effects of CO 2 enrichment on the growth and biometal/nutrient content and accumulation in Senna reticulata germinated under two different carbon dioxide concentrations: atmospheric (360 mg L -1 ) and elevated (720 mg L -1 ). Biometal/nutrient determinations were performed on three different plant portions (leaflets, stem and root) using flame atomic absorption spectrometry. In general, the biometal and nutrient stoichiometries in roots were increased, probably due to reduced transpiration, and consequent biometal accumulation. An Artifical Neural Network analysis suggests that Mg, Na and Fe display the most different behavior when comparing plants germinated at atmospheric and elevated CO 2 conditions. Biomass and growth increases and certain elemental levels indicate that S. reticulata benefits from increased CO 2 levels, however some results indicate the contrary, making further studies in this context necessary, as these changes may lead to direct effects on food safety, crop yields, and phytoremediation efficiency., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Biochemical imbalances, provoked by aging or a secondary illness, might directly affect the brain, causing severe problems, such as loss of memory or alteration of behavior patterns. Brain disorders are usually classified as injuries (such as stroke, hematomas, and concussions), tumors, and neurodegenerative (such as Parkinson's and Alzheimer's diseases) and mental (such as depression, bipolar disorder, schizophrenia) diseases. As the pathophysiology of these illnesses is not completely established and multiple factors are involved, metallomics, a bioanalytical strategy that allows the detection of metal ions and metalloproteins in diverse biological matrices, is of extreme relevance in identifying which elements are affected by a disease and/or treatment. Thus, determining which element ions suffer disturbances in their homeostasis during the disease progress is relevant to understand the biochemical changes and propose new drug targets. In addition, it is well known that oxidative stress plays an important role in the development of pathological neurodegenerative and mental diseases, which may be caused by metal ion dyshomeostasis, so it is also important to understand endogenous antioxidant metalloprotein and metalloenzyme mechanisms in this regard. In this context, recent applications of metallomics in the study of neurodegenerative and mental disorders are discussed in this chapter, as well as future trends in this research area.

Dam constructions in the Amazon have increased exponentially in the last decades, causing several environmental impacts and serious anthropogenic impacts in certain hydroelectric power plant reservoirs in the region have been identified. The assessment of the trophic status of these reservoirs is of interest to indicate man-made changes in the environment, but must take into account the hydrological cycle of the area. This can be relevant for environmental management actions, aiding in the identification of the ecological status of water bodies. In this context, physico-chemical parameters and eutrophication indicators were determined in a hydroelectric power plant reservoir in the Brazilian Amazon to assess trophic variations during the regional hydrological regime phases on the reservoir, namely dry, filling, full and emptying stages. The local hydrological regimes were shown to significantly influence TSS and turbidity, as well as NH 4 , NO 3 , PO 4 , with higher values consistently observed during the filling stage of the reservoir. In addition, differences among the sampling stations regarding land use, population and anthropogenic activities were reflected in the PO 4 3- values during the different hydrological phases.

To assess environmental contamination, studies have been increasingly carried out using biomarkers to diagnose the effects of toxic metal exposure, such as metallothionein (MT). In this context, the aims of the present study were to determine Cd, Cu, Ni and Pb concentrations, by ICP-MS, in liver samples from Mugil cephalus from the municipality of Ilhéus, located in North-Southeastern Brazil, in the state of Bahia, which has been increasingly suffering from anthropogenic pressure, and to quantify total MT in liver and gills. Among essential metals, copper (199.2 μg g -1 ) presented concentrations approximately 7 times higher than allowed by the World Health Organization (30 μg g -1 ). Liver samples showed higher concentrations than gills. Metallothionein concentrations indicate differential contamination along the study area. The first sampling showed higher induction of MT synthesis overall. Differences between liver and gill MT concentration trends were relatively minor, which may indicate the adequacy of analyzing gills in an environmental monitoring context.

The present study aimed to investigate metal bioaccumulation in mullet (M. liza) from a tropical bay located in Southeastern Brazil, comparing a previously considered reference site to a known contaminated area of the bay, as well as to conduct human health risk assessments with regard to the consumption of this species. The metal concentrations were compared to the maximum residue level (MRL) in foods established by the different national and international regulatory agencies, and the Provisional Tolerable Daily Intake (PTDI) was determined and compared to reference values. Chromium (Cr), Zinc (Zn), Copper (Cu), Manganese (Mn), Nickel (Ni), Cadmium (Cd) and Lead (Pb) concentrations were determined in the gills, muscle and liver of 28 mullet by ICP-MS after acid digestion. Certain metals exceeded MRL guidelines established by different regulatory agencies, indicating human health risks associated to these metals. PTDI values, however, did not exceed corresponding metal values proposed by the World Health Organization. The metal concentrations found in the mullet samples indicate that the previously considered reference site is now showing signs of anthropogenic contamination., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Metallomic studies regarding environmental contamination by metals are of value in elucidating metal uptake, trafficking, accumulation and metabolism in biological systems. Many proven bioindicator species, such as bivalves, have not yet, however, been well-characterized regarding their metalloprotein expression in response to environmental contaminants. In this context, the aim of the present study was to investigate metalloprotein expressions in the thermostable protein fraction of muscle tissue and digestive glands from mussels (Perna perna) from three differentially metal-contaminated sites in Southeastern Brazil in comparison with a reference site. The thermostable protein fractions were analyzed by SDS-PAGE and SEC-HPLC-ICP-MS. Metal content was also determined in both the crude and the purified extracts. Several inter-organ differences were observed, which is to be expected, while inter-site differences regarding thermostable protein content were also verified, indicating accumulation of these elements in muscle tissue and digestive glands and disruption of homeostasis of essential elements, with detoxification attempts by metal-bound proteins, since all metalloproteins present in both matrices eluted bound to at least one non-essential metal. These results are also noteworthy with regard to the adopted reference site, that also seems to be contaminated by toxic metals., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Guiana dolphins (Sotalia guianensis) are small cetaceans that inhabit coastal regions down to a 50 m depth. As a coastally distributed species, they are exposed to a variety of human-induced risks that include passive fishing nets, persistent environmental pollution, and emerging diseases. As a top predatorS. guianensis occupies an important ecological niche in marine ecosystems. However, this niche also exposes this dolphin to extensive biomagnification of marine contaminants that may accumulate and be stored throughout their life of about 30 years.In this paper, we have compiled available data on the Guiana dolphin as regards its exposure to chemical pollutants, pathogenic microbes, infectious diseases, and injuries caused by interactions with passive fishing gears. Our analysis of the data shows that Guiana dolphins are particularly sensitive to environmental changes.Although the major mortal threat to dolphins results from contact with fishing other human-related activities in coastal zones also pose risks and need more attention.Such human-related risks include the presence of persistent toxicants in the marine environment, such as PCBs and PBDEs. Residues of these chemicals have been detected in Guiana dolphin's tissues at similar or higher levels that exist in cetaceans from other known polluted areas. Another risk encountered by this species is the non lethal injuries caused by fishing gear. Several incidents of this sort have occurred along the Brazilian coast with this species. When injuries are produced by interaction with fishing gear, the dorsal fin is the part of the dolphin anatomy that is more affected, commonly causing severe laceration or even total loss.The Guiana dolphins also face risks from infectious diseases. The major ones thus far identified include giardiasis, lobomycosis, toxoplasmosis, skin and skeletal lesions. Many bacterial pathogens from the family Aeromonadaceae and Vibrionaceae have been isolated from Guiana dolphins. Several helminth species have also been observed to affectS. guianensis. These results suggest a vulnerability of this species to environmental disturbances. Moreover, there is some evidence that the effects of some infectious diseases may be enhanced from stress caused by habitat impairment. For example, certain diseases and pathogenic organisms in S.guianensis may be associated with the high levels of endocrine-disruptor contaminants(e.g., PCBs; DDTs; PBDEs) that have been detected in marine waters.Although the data available on S. guianensis is growing, most of the work has been focused on a small portion of the species total area of distribution. Most studies,to date, have been carried out in the Southern region of the distribution, and in north eastern Brazil. Few studies have been conducted in the northern region of the South America or in Central America. Therefore, future studies should be conducted that address the heterogeneity of this species total distribution.The biology and ecology of the Guiana dolphin renders this species potentially useful as a sentinel species for detecting environmental changes, such as chemical and biological pollution. Research about this dolphin is encouraged as a way to assess what coastal environmental changes have occurred and to continue evaluating the health status of this vulnerable species in a changing environment.