Rare Earth Element Accumulation in Fiddler Crabs (Minuca rapax) from the Rio Doce Tropical Estuary Strongly Affected by Mine Tailings Following the Fundão Disaster.

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.

Ecotoxicological assessments of atmospheric biomonitors exposed to urban pollution in a Brazilian metropolis.

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.

Smelly shark, smelly ray: what is infecting you?

AIMS: Although elasmobranchs are consumed worldwide, bacteriological assessments for this group are still sorely lacking. In this context, this study assessed bacteria of sharks and rays from one of the most important landing ports along the Rio de Janeiro coast. METHODS AND RESULTS: Bacteria were isolated from the cloacal swabs of the sampled elasmobranchs. They were cultured, and Vibrio, Aeromonas, and Enterobacterales were isolated and identified. The isolated bacteria were then biochemically identified and antimicrobial susceptibility assays were performed. Antigenic characterizations were performed for Salmonella spp. and Polymerase Chain Reaction (PCR) assays were performed to identify Escherichia coli pathotypes. Several bacteria of interest in the One Health context were detected. The most prevalent Enterobacterales were Morganella morganii and Citrobacter freundii, while Vibrio harveyi and Vibrio fluvialis were the most prevalent among Vibrio spp. and Aeromonas allosacharophila and Aeromonas veronii bv. veronii were the most frequent among Aeromonas spp. Several bacteria also displayed antimicrobial resistance, indicative of Public Health concerns. A total of 10% of Vibrio strains were resistant to trimethoprim-sulfamethoxazole and 40% displayed intermediate resistance to cefoxitin. Salmonella enterica strains displayed intermediate resistance to ciprofloxacin, nalidixic acid and streptomycin. All V. cholerae strains were identified as non-O1/non-O139. The detected E. coli strains did not exhibit pathogenicity genes. This is the first study to perform serology assessments for S. enterica subsp. enterica isolated from elasmobranchs, identifying the zoonotic Typhimurium serovar. Salmonella serology evaluations are, therefore, paramount to identify the importance of elasmobranchs in the epidemiological salmonellosis chain. CONCLUSIONS: The detection of several pathogenic and antibiotic-resistant bacteria may pose significant Public Health risks in Brazil, due to high elasmobranch consumption rates, indicating the urgent need for further bacteriological assessments in this group.

Metal and metalloid maternal transfer in a newborn West Indian manatee (Trichechus manatus) two years after the northeastern oil spill disaster of 2019 in Brazil.

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.

Baseline metal and metalloid contamination in two marine sponge species, Hymeniacidon heliophila and Desmapsamma anchorata, from southeastern Brazil.

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.

Review: Fish bile, a highly versatile biomarker for different environmental pollutants.

Ecotoxicological assessments encompass a broad spectrum of biochemical endpoints and ecological factors, allowing for comprehensive assessments concerning pollutant exposure levels and their effects on both fish populations and surrounding ecosystems. While these evaluations offer invaluable insights into the overall health and dynamics of aquatic environments, they often provide an integrated perspective, making it challenging to pinpoint the precise sources and individual-level responses to environmental contaminants. In contrast, biliary pollutant excretion assessments represent a focused approach aimed at understanding how fish at the individual level respond to environmental stressors. In this sense, the analysis of pollutant profiles in fish bile not only serves as a valuable exposure indicator, but also provides critical information concerning the uptake, metabolism, and elimination of specific contaminants. Therefore, by investigating unique and dynamic fish responses to various pollutants, biliary assessments can contribute significantly to the refinement of ecotoxicological studies. This review aims to discuss the multifaceted utility of bile as a potent biomarker for various environmental pollutants in fish in targeted monitoring strategies, such as polycyclic aromatic hydrocarbons, metals, pesticides, pharmaceuticals, estrogenic compounds, resin acids, hepatotoxins and per- and polyfluorinated substances. The main caveats of this type of assessment are also discussed, as well as future directions of fish bile studies.

A novel report on the emerging and zoonotic neurotropic fungus Trichosporon japonicum in the brain tissue of the endangered Brazilian guitarfish (Pseudobatos horkelii) off the southeastern coast of Brazil.

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.

The evolution of endocrine disruptor chemical assessments worldwide in the last three decades.

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.

A systematic review on polycyclic aromatic hydrocarbon contamination in elasmobranchs and associated human health risks.

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.

Ecotoxicology applied to conservation: Potential negative metal and metalloid contamination effects on the homeostatic balance of the critically endangered Brazilian guitarfish, Pseudobatos horkelii (Elasmobranchii: Rhinobatidae).

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.

A Novel One Health Approach concerning Yeast Present in the Oral Microbiome of the Endangered Rio Skate (Rioraja agassizii) from Southeastern Brazil.

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 (CHROMagarTM), 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.

A systematic review on metal contamination due to mining activities in the Amazon basin and associated environmental hazards.

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.

Trophic Chain Organochlorine Pesticide Contamination in a Highly Productive Upwelling Area in Southeastern Brazil.

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 as a Stress Indicator in Fish: Sampling Methods, Analytical Techniques, and Organic Pollutant Exposure Assessments.

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.

Metal bioaccumulation and genotoxicity in Oreochromis niloticus reared in farming pools influenced by mining activities in Napo, in the Ecuadorian Amazonia.

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 (CSFing) 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.

First report on the serum chemistry and haematology of free-ranging dusky (Carcharhinus obscurus) and sandbar (Carcharhinus plumbeus) sharks in the eastern Mediterranean Sea.

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.

First description of a Gammaherpesvirus in a common dolphin (Delphinus delphis) from the Eastern Mediterranean Sea.

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.

Carbonic anhydrase in elasmobranchs and current climate change scenario implications.

The enzyme carbonic anhydrase (CA) has well-known functions in acid-base balance, respiratory gas exchange, and osmoregulation in teleost fishes. However, studies concerning the role of CA in elasmobranchs are still scarce. Therefore, the aim of this study is to present the current status of CA studies in sharks and rays, as well as to identify gaps and emerging needs, in order to guide future studies. This review is organized according to the main roles of CA, with further considerations on climate change and CA effects indicated as paramount, as strategies in the face of climate change can be crucial for species response. The literature review revealed a reduction in publications on CA over the years. In addition, a historical research differentiation is noted, where the first assessments on the subject addressed investigations on basic CA functions, while the most recent studies present a comparative approach among species as well as interdisciplinary discussions, such as ecology and phylogeny. Considering that several elasmobranchs are threatened, future studies should prioritize non-lethal methodologies, in addition to expanding studies to climate change effects on CA.

First metal and metalloid study assessment for the Black Triggerfish Melichthys niger (Bloch, 1786): Baseline data from a pristine South Atlantic oceanic island.

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.

Serious lesions in Green turtles (Chelonia mydas) afflicted by fatal Spirorchiidiasis found stranded in south and southeastern Brazil.

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.