Perfluoroalkyl contaminants in plasma of five sea turtle species: comparisons in concentration and potential health risks

Partitioning of PFAS to serum, tissues, eggs, and hatchlings of an Australian freshwater turtle

Turtles are a potential sentinel species of aquatic ecosystem health as they inhabit aquatic ecosystems, are long lived, and potentially have high exposure to anthropogenic chemicals via food and water. This study investigated per- and polyfluoroalkyl substances (PFAS) tissue partitioning in female Emydura macquarii macquarii turtle, and the maternal offloading of (PFAS) into eggs and then hatchlings as well as the accumulation of PFAS in male and female Emydura macquarii macquarii serum. Significantly higher levels of perfluorosulfonic acids (PFSAs) and perfluorocarboxylic acids (PFCAs) were measured in the male serum compared to the female turtle serum, whereas perfluoroalkane sulfonamides (FASAs) were significantly higher in the female turtle serum. Perfluorooctane sulfonate (PFOS) was the predominant PFAS in the turtles whereas PFHxA was the predominant PFAS found in the surrounding water. PFHxA was not reported in any turtle tissue or the serum. The short-chain PFSAs and FASAs appeared to be highly associated with blood; long-chain PFSAs and PFCAs were more likely to be associated with tissue. Half of the PFHxS and all the long-chain PFSAs and PFCAs reported in the yolks were transferred into the hatchlings (by mass), suggesting a potential intergenerational effect.

Poly- and perfluoroalkyl substances (PFASs) in amphibians and reptiles - exposure and health effects

Poly- and perfluoroalkyl substances (PFASs) are commonly used in various industries and everyday products, including clothing, electronics, furniture, paints, and many others. PFASs are primarily found in aquatic environments, but also present in soil, air and plants, making them one of the most important and dangerous pollutants of the natural environment. PFASs bioaccumulate in living organisms and are especially dangerous to aquatic and semi-aquatic animals. As endocrine disruptors, PFASs affect many internal organs and systems, including reproductive, endocrine, nervous, cardiovascular, and immune systems. This manuscript represents the first comprehensive review exclusively focusing on PFASs in amphibians and reptiles. Both groups of animals are highly vulnerable to PFASs in the natural habitats. Amphibians and reptiles, renowned for their sensitivity to environmental changes, are often used as crucial bioindicators to monitor ecosystem health and environmental pollution levels. Furthermore, the decline in amphibian and reptile populations worldwide may be related to increasing environmental pollution. Therefore, studies investigating the exposure of amphibians and reptiles to PFASs, as well as their impacts on these organisms are essential in modern toxicology. Summarizing the current knowledge on PFASs in amphibians and reptiles in a single manuscript will facilitate the exploration of new research topics in this field. Such a comprehensive review will aid researchers in understanding the implications of PFASs exposure on amphibians and reptiles, guiding future investigations to mitigate their adverse effects of these vital components of ecosystems.

Occurrence and pattern of legacy and emerging per- and Poly-FluoroAlkyl substances (PFAS) in eggs of loggerhead turtle Caretta caretta from western Mediterranean

Per-and Poly-FluoroAlkyl Substances (PFAS) are a class of persistent, toxic, and mobile and chemicals both from industrial sources and from the use and disposal of Consumers products containing PFAS, whose concentration in marine food webs could pose a toxicological risk for biota and humans. In 2021, unhatched eggs were sampled from 41 loggerhead turtle Caretta caretta nests from the Italian shores of the Campania Region (Southern Italy). Whole eggs were analysed for the presence of 66 legacy and emerging PFAS with Liquid Chromatography coupled to Hybrid High Resolution Mass Spectrometry. A median Σ66 Per- and Poly-FluoroAlkyl Substances value of 3.34 ng/g egg fresh weight was found; perfluoroctane sulfonate (PFOS) represented the most contributing congener (47%), followed by perfluoro-n-undecanoic acid, perfluoro-n-tridecanoic acid, perfluoro-n-decanoic acid, perfluoro-n-decanoic acid, and perfluoro-n-tetradecanoic acid, respectively. Such compounds showed a log-norm distribution, suggesting found concentrations could represent the baseline levels in the considered sampling area. Emerging ChloroPolyFluoroPolyEthers Carboxylic Acids (ClPFECAs) were found in 20 out of 41 samples in the range 0.01-1.59 ng/g. Four samples had 20-100 fold higher concentration compared to that of other samples, suggesting the presence of hot spot areas possibly related to presence of fluoropolymer-based marine litter turtles may ingest. The analysis of two paired eggs/liver samples recovered from stranded animals revealed PFAS concentration in the same order of magnitude, supporting the role of vitellogenin in their selective transfer to yolk. Significant (P = 0.0155) Kendall negative correlation coefficient of -0.2705 among PFOS content in eggs and the recorded hatching success prompts for further investigation on associated exposure assessment and related eco-toxicity risk. This work reports for the first time PFAS presence in georeferenced loggerhead turtle eggs of the Mediterranean Sea and results represent a starting point to study PFAS time-trends in this vulnerable species.

Sex-Specific Bioaccumulation, Maternal Transfer, and Tissue Distribution of Legacy and Emerging Per- and Polyfluoroalkyl Substances in Snakes (Enhydris chinensis) and the Impact of Pregnancy

The effects of sex and pregnancy on the bioaccumulation and tissue distribution of legacy and emerging per- and polyfluoroalkyl substances (PFASs) in Chinese water snakes were investigated. The bioaccumulation factor of PFASs showed a positive correlation with their protein-water partition coefficients (log K_PW), and steric hindrance effects were observed when the molecular volume was > 357 ų. PFAS levels in females were significantly lower than those in males. The chemical composition of pregnant females was significantly different from that of non-pregnant females and males. The maternal transfer efficiencies of perfluorooctane sulfonic acid were higher than those of other PFASs, and a positive correlation between the maternal transfer potential and log K_PW was observed for other PFASs. Tissues with high phospholipid content exhibited higher concentrations of ∑PFASs. Numerous physiological changes occurred in maternal organ systems during pregnancy, leading to the re-distribution of chemicals among different tissues. The change in tissue distribution of PFASs that are easily and not-so-easily maternally transferred was in the opposite direction. The extent of compound transfer from the liver to the egg determined tissue re-distribution during pregnancy.

Hawksbill Sea Turtle (Eretmochelys imbricata) Blood and Eggs Organochlorine Pesticides Concentrations and Embryonic Development in a Nesting Area (Yucatan Peninsula, Mexico)

Environmental contaminants with chemical origins, such as organochlorine pesticides (OCPs) have major impacts on the health of marine animals, including sea turtles, due to the bioaccumulation of those substances by transference throughout the food chain. The effects of environmental pollution on the health of marine turtles are very important for management strategies and conservation. During recent decades, the south Gulf of Mexico and the Yucatan Peninsula have suffered from increasingly frequent disturbances from continental landmasses, river systems, urban wastewater runoff, port areas, tourism, industrial activities, pesticides from agricultural use, and other pollutants, such as metals, persistent organic pollutants (POPs) and hydrocarbons (from the oil industry activities), which contaminate water and sediments and worsen the environmental quality of the marine ecosystem in this region. In this study, we assessed the concentrations of OCPs in the blood and eggs of 60 hawksbill turtles (Eretmochelys imbricata) nesting at the Punta Xen turtle camp, and their effects on the nesting population's reproductive performance: specifically, maternal transfer and embryonic development were analyzed. Hematologic characteristics, including packed cell volume, white blood cell count, red blood cell count, and haemoglobin levels, and plasma chemistry values, including creatinine, blood urea nitrogen, uric acid, triglyceride, total cholesterol and glucose, were also measured. The general health of the turtles in this study, as well as their levels of urea, serum creatinine, glucose, uric, acid, cholesterol, and triglyceride, fell within normal ranges and was similar to other normal values, which could indicate the turtles' good energy levels and body conditions for nest-building activity, with all of the turtles able to successfully come ashore to nest. All the same, the obtained results also indicate that OCPs affect the nesting and reproductive performance of the hawksbill turtles, as well as their fertility and the development of the population of eggs and reproductive performance, specifically in terms of maternal transference and embryonic development. There were significant differences in the concentrations of OCPs (ΣHCHs and ΣDienes) between maternal blood and eggs, indicating that these chemicals are transferred from nesting females to eggs and, ultimately, to hatchlings. OCPs may, therefore, have an effect on the health and reproductive performance of hawksbill turtles, both in terms of their fertility and egg development. Conservation strategies need to be species-specific, due to differences in feeding, and address the reasons for any decline, focusing on regional assessments. Thus, accurate and comparable monitoring data are necessary, which requires the standardization of monitoring protocols.

Host–Gut Microbiome Metabolic Interactions in PFAS-Impacted Freshwater Turtles (Emydura macquarii macquarii)

Per-and polyfluoroalkyl substances (PFAS) are a growing concern for humans, wildlife, and more broadly, ecosystem health. Previously, we characterised the microbial and biochemical impact of elevated PFAS on the gut microbiome of freshwater turtles (Emydura macquarii macquarii) within a contaminated catchment in Queensland, Australia. However, the understanding of PFAS impacts on this species and other aquatic organisms is still very limited, especially at the host–gut microbiome molecular interaction level. To this end, the present study aimed to apply these leading-edge omics technologies within an integrated framework that provides biological insight into the host turtle–turtle gut microbiome interactions of PFAS-impacted wild-caught freshwater turtles. For this purpose, faecal samples from PFAS-impacted turtles (n = 5) and suitable PFAS-free reference turtles (n = 5) were collected and analysed. Data from 16S rRNA gene amplicon sequencing and metabolomic profiling of the turtle faeces were integrated using MetOrigin to assign host, microbiome, and co-metabolism activities. Significant variation in microbial composition was observed between the two turtle groups. The PFAS-impacted turtles showed a higher relative abundance of Firmicutes and a lower relative abundance of Bacteroidota than the reference turtles. The faecal metabolome showed several metabolites and pathways significantly affected by PFAS exposure. Turtles exposed to PFAS displayed altered amino acid and butanoate metabolisms, as well as altered purine and pyrimidine metabolism. It is predicted from this study that PFAS-impacted both the metabolism of the host turtle and its gut microbiota which in turn has the potential to influence the host’s physiology and health.

Detection of long chain per- and polyfluoroalkyl substances (PFAS) in the benthic Golden tilefish (Lopholatilus chamaeleonticeps) and their association with microscopic hepatic changes

Oceans are major sinks for anthropogenic pollutants, including per- and polyfluoroalkyl substances (PFAS). Although PFAS have been detected in surface waters globally, this is the first report of PFAS in a deep (170-400 m) demersal species in the Gulf of Mexico (GoM). Golden Tilefish (Lopholatilus chamaeleonticeps) plasma extracts (n = 185) were investigated for the presence of PFAS using ultra-high performance liquid chromatography-tandem mass spectrometry. A subset of liver tissues (n = 51) were also analyzed for microscopic hepatic changes (MHCs). Overall, nine of the 110 PFAS targeted were detected in Tilefish plasma at relatively high frequencies. Plasma concentrations of total PFAS (Σ₉PFAS) ranged from below the detection limit to 27.9 ng g^-1 w.w. Significant regional differences were observed with the highest concentrations of PFAS detected in the north central region of the GoM, where substantial industrialization and discharges from the Mississippi River occur. Compared to most wildlife and matrices analyzed globally, the PFAS profiles in Tilefish were unique as they are dominated by PFUnDA. Profile differences are hypothesized to be the result of Tilefish's distinctive lifestyle, habitat, diet, and partitioning characteristics of long-chain PFAS. Several MHCs were identified in this subset of Tilefish that could be detrimental to their health. Significant correlations between PFAS concentrations and biometric indices and MHCs were evident, however, additional research is needed to investigate the role PFAS and PFAS combined with chemical admixtures may play in inducing observed hepatic changes and other physiological effects in Tilefish. These findings give insight into the fate of PFAS at depth in aquatic ecosystems and are cause for concern regarding the health of other deep water benthic biota in GoM and other deepwater sinks for PFAS.

Bioaccumulation and metabolic response of PFAS mixtures in wild-caught freshwater turtles (Emydura macquariimacquarii) using omics-based ecosurveillance techniques

PFAS mixtures in the environment are common and identifying PFAS constituents, bioaccumulation, and biological impacts of mixtures remains a challenge. Here, an omics-based ecosurveillance approach was taken to investigate the impacts of PFAS pollution in freshwater turtles (Emydura macquariimacquarii). Four turtles were collected from an impacted waterway downstream from an industrial source of PFAS contamination in Queensland, Australia and analysed for 49 different PFAS. One turtle was collected from a suitable control site. PFAS concentrations were quantified in turtle serum using an established targeted methodology. The serum PFAS concentration was ten-fold greater at the impacted site (Σ49 PFAS 1933 ± 481 ng/mL) relative to the control sample (Σ49 PFAS 140 ng/mL). Perfluorooctane sulfonate (PFOS; 889 ± 56 ng/mL) was 235 times higher in turtle serum than in the water that they were collected from (ΣPFAS 32.0 μg/L). Perfluorobutane sulfonamide (FBSA; 403 ± 83 ng/mL) and perfluorohexane sulfonamide (FHxSA; 550 ± 330 ng/mL) were also reported at substantial concentrations in the serum of impacted turtles. Biochemical profiles were analysed using a mixture of liquid chromatography triple quadrupole (QqQ) and quadrupole time-of-flight (QToF) mass spectrometry methodologies. These profiles demonstrated a positive correlation in the impacted turtles exposed to elevated PFAS with an enhanced purine metabolism, glycerophosphocholines and an innate immune response, which suggest an inflammation response, metabolic preservation and re-routing of central carbon metabolites. Conversely, lipid transport and binding activity were negatively correlated. Using these preliminary data, we were able to demonstrate the negative metabolic impact from PFAS mixtures on turtle metabolic health. With further research on a larger turtle cohort, omics-based data will contribute towards linking adverse outcome pathways for turtle populations exposed to PFAS mixtures. Moreover, expanding the use of ecosurveillance tools will inform mechanistic toxicological data for risk assessment and regulatory applications.

Characterization of Halogenated Organic Compounds in Pelagic Sharks and Sea Turtles Using a Nontargeted Approach

Halogenated organic compounds (HOCs) in marine species collected from the Atlantic Ocean [3 shortfin mako (Isurus oxyrinchus) and 1 porbeagle (Lamna nasus)], and 12 sea turtles collected from the Pacific Ocean [3 loggerhead (Caretta caretta), 3 green (Chelonia mydas), 3 olive ridley (Lepidochelys olivacea), and 3 hawksbill (Eretmochelys imbricata)] were analyzed with a nontargeted analytical method using two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Sharks and sea turtles had distinct HOC profiles. Halogenated methoxyphenols (halo-MeOPs) were the most abundant compound class identified in sea turtle livers, while polychlorinated biphenyls (PCBs) were the most abundant in shark livers. In addition to legacy contaminants and halo-MeOPs, a total of 110 nontargeted/novel HOCs (NHOCs) were observed in the shark livers. Shortfin mako collected from the northern Gulf of Mexico contained the largest number (89) and most diverse structural classes of NHOCs. Among all NHOCs, a group of compounds with the elemental composition C₁₄H_12-nCl_n (n = 5-8) exhibited the highest concentrations, followed by chlorocarbazoles and tris(chlorophenyl) methanes (TCPMs). Using nontargeted workflows, a variety of known and unknown HOCs were observed, which demonstrate the need to develop more complete chemical profiles in the marine environment.

Differences in marine megafauna in vitro sensitivity highlights the need for species-specific chemical risk assessments

Sea turtles, dolphins and dugongs can be exposed to large mixtures of contaminants due to the proximity of foraging locations to anthropogenic inputs. Differences in accumulation and effect result in differences of chemical risk to these species. However, little is known about the effect of contaminants in marine wildlife. Cell-based, or in vitro, exposure experiments offer an ethical alternative to investigate the effect of contaminants in wildlife. Data from in vitro studies can then be placed in an environmental context, by using screening risk assessments, comparing effect data with accumulation data from the literature, to identify risk to populations of marine wildlife. Cytotoxicity of Cr⁶⁺, Cd²⁺, Hg²⁺, 4,4'-DDE, and PFNA were investigated in primary skin fibroblasts of green turtles, loggerhead turtles, hawksbill turtles, dugongs, Burrunan dolphins, and common bottlenose dolphins. The general order of toxicity for all species was Hg²⁺> Cr⁶⁺ > Cd²⁺> 4,4'-DDE > PFNA, and significant differences in cytotoxicity were found between species for Cr⁶⁺, Cd²⁺ and PFNA. For Cd²⁺, in particular, cells from turtle species were less sensitive than mammalian species, and dugong cells were by far the most sensitive. The results from the cytotoxicity assay were then used in combination with published data on tissue contaminant concentrations to calculate risk quotients for identifying populations of each species most at risk from these chemicals. Cr, Cd and Hg were identified as posing risk in all six species. Dugongs were particularly at risk from Cd accumulation and dolphin species were particularly at risk from Hg accumulation. These results demonstrate the importance of using species-specific effect and accumulation data for developing chemical risk assessments and can be used to inform managers of priority contaminants, species, or populations. Development of additional in vitro endpoints, and improving links between in vitro and in vivo effects, would further improve this approach to understanding chemical risk in marine megafauna.

Systematic review of reptile reproductive toxicology to inform future research directions on endangered or threatened species, such as sea turtles

Threatened or endangered reptiles, such as sea turtles, are generally understudied within the field of wildlife toxicology, with even fewer studies on how contaminants affect threatened species reproduction. This paper aimed to better inform threatened species conservation by systematically and quantitatively reviewing available research on the reproductive toxicology of all reptiles, threatened and non-threatened. This review found 178 studies that matched our search criteria. These papers were categorized into location conducted, taxa studied, species studied, effects found, and chemicals investigated. The most studied taxa were turtles (n = 87 studies, 49%), alligators/crocodiles (n = 54, 30%), and lizards (n = 37, 21%). Maternal transfer, sex steroid alterations, sex reversal, altered sexual development, developmental abnormalities, and egg contamination were the most common effects found across all reptile taxa, providing guidance for avenues of research into threatened species. Maternal transfer of contaminants was found across all taxa, and taking into account the foraging behavior of sea turtles, could help elucidate differences in maternal transfer seen at nesting beaches. Sex steroid alterations were a common effect found with contaminant exposure, indicating the potential to use sex steroids as biomarkers along with traditional biomarkers such as vitellogenin. Sex reversal through chemical exposure was commonly found among species that exhibit temperature dependent sex determination, indicating the potential for both environmental pollution and climate change to disrupt population dynamics of many reptile species, including sea turtles. Few studies used in vitro, DNA, or molecular methodologies, indicating the need for more research using high-throughput, non-invasive, and cost-effective tools for threatened species research. The prevalence of developmental abnormalities and altered sexual development and function indicates the need to further study how anthropogenic pollutants affect reproductive output in threatened reptiles.

Sea turtles across the North Pacific are exposed to perfluoroalkyl substances

Perfluorinated alkyl substances (PFASs) are global, persistent, and toxic contaminants. We assessed PFAS concentrations in green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles from the North Pacific. Fifteen compounds were quantified via liquid chromatography tandem mass spectrometry from 62 green turtle and 6 hawksbill plasma samples from Hawai'i, Palmyra Atoll, and the Northern Marianas Islands. Plasma from 14 green turtles severely afflicted with fibropapillomatosis, and eggs from 12 Hawaiian hawksbill nests from 7 females were analyzed. Perfluorooctane sulfonate (PFOS) predominated in green turtle plasma; perfluorononanoic acid (PFNA) predominated in hawksbill tissues. Concentrations were greater in hawksbill than green turtle plasma (p < 0.05), related to trophic differences. Green turtle plasma PFOS concentrations were related to human populations from highest to lowest: Hawai'i, Marianas, Palmyra. Influence on fibropapillomatosis was not evident. PFASs were maternally transferred to hawksbill eggs, with decreasing concentrations with distance from airports and with clutch order from one female. A risk assessment of PFOS showed concern for immunosuppression in Kailua green turtles and alarming concern for hawksbill developmental toxicity. Perfluoroundecanoic (PFUnA) and perfluorotridecanoic (PFTriA) acid levels were correlated with reduced emergence success (p < 0.05). Studies to further examine PFAS effects on sea turtle development would be beneficial.

Postmortem investigations on leatherback sea turtles (Dermochelys coriacea) stranded in the Canary Islands (Spain) (1998-2017): Evidence of anthropogenic impacts

Opportunities for postmortem studies on leatherback sea turtles (Dermochelys coriacea) are infrequent due to their predominantly pelagic life history. In this study, the pathological findings and causes of mortality of 13 leatherback turtles stranded in the Canary Islands, Spain, from 1998 to 2017, are described. In addition, concentrations of Se, As, Cd, Pb, Hg, 15 rare earth elements (REE) and other 4 minor elements (ME), 41 persistent organic pollutants, and 16 polycyclic aromatic hydrocarbons in hepatic samples from 5 leatherbacks were determined. 84.62% of the turtles died possibly due to anthropogenic causes (entanglement/fishing interaction - 46.15%; boat strike - 23.07%; plastic ingestion - 15.38%). Although Se, As, and Cd were found at higher hepatic concentrations than those reported for leatherbacks from other locations, no acute lesions were detected. This is the first report of exposure to REE-ME in sea turtles. Organic contaminant hepatic concentrations were generally low or undetectable.

Integrative developmental biology in the age of anthropogenic change

Humans are changing and challenging nature in many ways. Conservation Biology seeks to limit human impacts on nature and preserve biological diversity. Traditionally, Developmental Biology and Conservation Biology have had nonoverlapping objectives, operating in distinct spheres of biological science. However, this chasm can and should be filled to help combat the emerging challenges of the 21st century. The means by which to accomplish this goal were already established within the conceptual framework of evo- and eco-devo and can be further expanded to address the ways that anthropogenic disturbance affect embryonic development. Herein, I describe ways that these approaches can be used to advance the study of reptilian embryos. More specifically, I explore the ways that a developmental perspective can advance ongoing studies of embryonic physiology in the context of global warming and chemical pollution, both of which are known stressors of reptilian embryos. I emphasize ways that these developmental perspectives can inform conservation biologists trying to develop management practices that will address the complexity of challenges facing reptilian embryos.

Assessing the Ecological Risks of Per- and Polyfluoroalkyl Substances: Current State-of-the Science and a Proposed Path Forward

Per- and poly-fluoroalkyl substances (PFAS) encompass a large, heterogenous group of chemicals of potential concern to human health and the environment. Based on information for a few relatively well-understood PFAS such as perfluorooctane sulfonate and perfluorooctanoate, there is ample basis to suspect that at least a subset can be considered persistent, bioaccumulative, and/or toxic. However, data suitable for determining risks in either prospective or retrospective assessments are lacking for the majority of PFAS. In August 2019, the Society of Environmental Toxicology and Chemistry sponsored a workshop that focused on the state-of-the-science supporting risk assessment of PFAS. The present review summarizes discussions concerning the ecotoxicology and ecological risks of PFAS. First, we summarize currently available information relevant to problem formulation/prioritization, exposure, and hazard/effects of PFAS in the context of regulatory and ecological risk assessment activities from around the world. We then describe critical gaps and uncertainties relative to ecological risk assessments for PFAS and propose approaches to address these needs. Recommendations include the development of more comprehensive monitoring programs to support exposure assessment, an emphasis on research to support the formulation of predictive models for bioaccumulation, and the development of in silico, in vitro, and in vivo methods to efficiently assess biological effects for potentially sensitive species/endpoints. Addressing needs associated with assessing the ecological risk of PFAS will require cross-disciplinary approaches that employ both conventional and new methods in an integrated, resource-effective manner. Environ Toxicol Chem 2021;40:564-605. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Changes in global protein expression in sea turtle cells exposed to common contaminants indicates new biomarkers of chemical exposure

Non-targeted protein expression at the cellular level can provide insights into mechanistic effects of contaminants in wildlife, and hence new and potentially more accurate biomarkers of exposure and effect. However, this technique has been relatively unexplored in the realm of in vitro biomarker discovery in threatened wildlife, despite the vulnerability of this group of animals to adverse sublethal effects of contaminant exposure. Here we examined the usefulness of non-targeted protein expression for biomarker discovery in green sea turtles (Chelonia mydas) by investigating differences in the response of primary cells from five different tissue types that were exposed to three contaminants known to accumulate in this species. Cells derived from C. mydas skin, liver, kidney, ovary and small intestine were exposed to 100 μg/L of either polychlorinated biphenyl 153 (PCB153), perfluorononanoic acid (PFNA) or phenanthrene for 24 h. The global protein expression was then quantitatively evaluated using sequential window acquisition of all theoretical mass spectra (SWATH-MS). Comparison of the global protein profiles revealed that, while a majority of proteins were mutually expressed in controls of all tissue types (~90%), the response to exposure in terms of protein expression strength was significantly different between tissue types. Furthermore, a comparison to known markers of chemical exposure in sea turtles from the literature indicated that in vitro response can reflect known in vivo responses. In particular, markers such as heat shock protein (HSP) 60, glutathione S-transferases (GSTs) and superoxide dismutases (SODs), cytochrome P450 and catalase were dysregulated in response to exposure. Furthermore, potential new markers of exposure were discovered such as annexin, an important protein in cell signalling processes. While this methodology proved promising further studies are required to confirm the accuracy of in vitro protein expression as a tool for biomarker discovery in wildlife.

Per- and polyfluoroalkyl substances (PFASs) in contaminated coastal marine waters of the Saudi Arabian Red Sea: a baseline study

Per- and polyfluoroalkyl substances (PFASs) are today considered important constituents of the continuously growing substance group of persistent contaminants of emerging environmental concern (PCEC). Here, we report for the first time the concentrations of 12 relevant PFASs in 28 marine water samples from the Saudi Arabian coastal waters of the Red Sea. The sum levels of 12 PFASs (Σ₁₂ PFAS) in surface seawater ranged from <LOQ to 956 ngL^-1. For the reference background site of this study, Σ₁₂ PFAS levels ranged from <LOQ to 10.9 ng/L. The highest PFAS levels have been found in Al-Arbaeen and Al-Shabab, two lagoons continuously receiving treated sewage effluents. PFHxA, PFHxS, and 6:2 FTS were the most prevalent PFASs with relatively high concentrations. Discharge of municipal and industrial wastewaters is considered an important source of PFASs. The pattern of PFASs observed here suggests that the usage of PFAS-containing aqueous film-forming foams (AFFFs) is a potential additional source for these compounds in Al-Arbaeen and Al-Shabab lagoons. However, a systematic elucidation of local PFASs sources is needed. Contamination of the Red Sea waters with PFASs poses a potential imminent risk to the marine environment of the Red Sea and ultimately may even affect the health of human consumers through the consumption of local seafood.

Perfluorooctanoic acid exposure impact a trade-off between self-maintenance and reproduction in lizards (Eremias argus) in a gender-dependent manner

The trade-off between self-maintenance and reproduction has been explored wildly in reptiles. However, the effects of exogenous pollutants on the life history traits of reptiles have not been paid attention to. In the current study, lizards (Eremias argus), living in the soil polluted by perfluorooctanoic acid (PFOA) were selected as the main focus. Bodyweight, survival rate, clutch characteristics and biochemical analysis (immune response, lipid accumulation, sex steroid secretion, antioxidant level, and metabolomics) were investigated and the results revealed that lizards' life-history trade-offs are gender-dependent: females were more inclined to choose a "Conservative" life-history strategy. After 60 days of exposure to PFOA, larger body weight, higher survival rate, stronger immune response, and lighter egg mass in females suggested that their trade-offs are more biased towards self-maintenance. Whereas, the "Risk" strategy would more popular among males: reduced body weight and survival rate, and suffering from oxidative damage indicated that males made little investment in self-maintenance.

Liquid chromatography tandem mass spectrometry for the quantification of steroid hormone profiles in blubber from stranded humpback whales (Megaptera novaeangliae)

Marine mammal blubber is known to have quantifiable concentrations of steroid hormones and is increasingly chosen as a matrix for the detection of these reproductive and stress biomarkers. Steroid hormones act through complex cascades, often in concert, yet studies conducted on cetaceans have rarely measured more than two steroids simultaneously. Due to the role of steroid hormones in multiple physiological processes, and variability in concentration among individuals, data on single compounds are often difficult to interpret. Here a liquid chromatography tandem mass spectrometry method for the simultaneous analyses of multiple steroid hormones in cetacean blubber was validated and applied to samples from 10 stranded humpback whales (Megaptera novaeangliae). Progesterone, 17α-hydroxyprogesterone, testosterone, androstenedione, oestrone, oestradiol, cortisone, cortisol, corticosterone and 11-deoxycorticosterone were reliably (relative standard deviation on six replicates <15%) and accurately (recovery of an amended sample between 70% and 120%) quantified, but not 11-deoxycortisol. With the exception of progesterone, testosterone, oestradiol and cortisol, these compounds were quantified for the first time in humpback whales. Given that blubber is frequently collected from free-swimming cetaceans in ongoing research programs, the technique developed here could substantially strengthen understanding and monitoring of the physiological condition of these species.

Examining the relationships between blubber steroid hormones and persistent organic pollutants in common bottlenose dolphins

Odontocete cetaceans bioaccumulate high concentrations of endocrine disrupting persistent organic pollutants (POPs), including dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyltrichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) - collectively DDTs - but few studies have explored DDTs-mediated endocrine disruption in cetaceans. Herein, we use remotely collected blubber biopsies from common bottlenose dolphins (Tursiops truncatus) inhabiting a site with high localized DDTs contamination to study the relationships between DDTs exposure and steroid hormone homeostasis in cetaceans. We quantified blubber steroid hormone concentrations by liquid chromatography-tandem mass spectrometry and blubber POP concentrations by gas chromatography-mass spectrometry. We detected six steroid hormones in blubber, including progesterone (P₄), 17-hydroxyprogesterone (17OHP₄), androstenedione (AE), testosterone (T), cortisol (F), and cortisone (E). Sampled dolphins (n = 62) exhibited exposure to DDT, DDE, DDD, chlordanes (CHLDs), mirex, dieldrin, hexachlorobenzene, polychlorinated biphenyls (PCBs), and brominated diphenyl ethers (BDEs). Using principal components analysis (PCA), we determined that blubber DDTs primarily loaded to the first principal component (PC1) explaining 81.6% of the total variance in POP exposure, while the remaining POPs primarily loaded to the PC2 (10.4% of variance). PC1 scores were negatively correlated with blubber T in males and blubber F in females, suggesting that exposure to DDTs impacted androgen and corticosteroid homeostasis. These conclusions were further supported by observed negative correlations between T and o,p'-DDE, o,p'-DDD, and p,p'-DDD in males sampled in the fall, and between F and the six individual DDTs and ∑₆DDTs in females. Overall, these results suggest that POP-mediated endocrine disruption may have occurred in this stock of dolphins, which could negatively impact their health and fitness. However, this study relied on uncontrolled incidental exposures, making it impossible to establish a causal relationship between DDTs exposure and endocrine effects. Importantly, this study demonstrates that remotely collected blubber biopsies are a useful matrix for studying endocrine disruption in marine mammals.

Per- and polyfluoroalkyl substances (PFAS) in plasma of the West Indian manatee (Trichechus manatus)

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous, synthetic anthropogenic chemicals known to infiltrate and persist in biological systems as a result of their stability and bioaccumulation potential. This study investigated 15 PFAS, including short-chain carboxylic and sulfonic acids, and their presence in a threatened herbivore, the West Indian manatee (Trichechus manatus). Seven of the 15 PFAS examined were detected in manatee plasma. Perfluorooctanesulfonic acid (PFOS) (ranging from 0.13 to 166 ng/g ww) and perfluorononanoic acid (PFNA) (ranging from 0.038 to 3.52 ng/g ww) were detected in every manatee plasma sample examined (n = 69), with differing medians across sampling sites in Florida, Crystal River (n = 39), Brevard County (n = 18), Everglades National Park (n = 8), and four samples (n = 4) from Puerto Rico. With an herbivorous diet and long life-span, the manatee provides a new perspective to monitoring PFAS contamination.

Perfluoroalkyl substances in diamondback terrapins (Malaclemys terrapin) in coastal South Carolina

This study focused on an estuarine wildlife species exhibiting high site fidelity and ubiquitous distribution in coastal environments along the Atlantic and Gulf coasts of the United States to monitor per- and polyfluoroalkyl substances (PFAS). A total of 75 diamondback terrapin (Malaclemys terrapin) plasma samples were collected from five creeks associated with Kiawah (Oyster Creek, Fiddler Creek, Sandy Creek, Gnat Creek) and Edisto (Townsend Creek) islands in Charleston County, South Carolina and investigated for 15 legacy PFAS. Of those, PFHxS was the only PFAS found in all terrapin plasma samples. Four additional PFAS were routinely detected (greater than 90% of the samples) and were included in statistical analyses: PFOS, PFNA, PFDA, and PFUnA. Sex-differences were observed for two creeks with male plasma containing higher PFAS than female plasma (PFHxS at Townsend Creek, PFOS at Oyster Creek). Sex-specific site differences in PFAS concentrations were observed primarily for males, suggesting male terrapins may be more sensitive indicators of localized contaminant profiles than females. Three PFAS were observed to have negative correlations with body mass: PFOS in males (p = 0.045, tau = -0.220), PFNA in males (p = 0.016, tau = -0.269), and PFHxS in both males (p = 0.007, tau = -0.302) and females (p = 0.001, tau = -0.379). No relationships for body mass and PFDA and PFUnA were observed.

Characterization of circulating steroid hormone profiles in the bottlenose dolphin (Tursiops truncatus) by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

Systemic steroid hormone measurements are often used in the assessment of reproductive, developmental, and stress physiology in vertebrates. In protected wildlife, such as the common bottlenose dolphin (Tursiops truncatus), these measures can provide critical information about health and fitness to aid in effective conservation and management. Circulating steroid hormone concentrations are typically measured by immunoassays, which have imperfect specificity and are limited to the measurement of a single hormone per assay. Here we demonstrate that reverse phase solid phase extraction (SPE) coupled to liquid chromatography tandem mass spectrometry (LC-MS/MS) allows for the simultaneous, precise (<15% relative standard deviation), and accurate (between 70% and 120% recovery of spiked quantities) measurement of at least seven steroid hormones in dolphin plasma. These seven steroid hormones include three hormones that have been measured previously in bottlenose dolphin blood (progesterone, testosterone, and cortisol) and three hormones which have never been quantified in dolphin blood (17-hydroxyprogesterone, androstenedione, cortisone, and corticosterone). While 17β-estradiol was not detected endogenously, we were able to accurately and precisely measure spiked quantities estradiol. Measures from plasma were more precise (i.e., lower RSD) than serum, and thus we recommend plasma as the preferred matrix for this analytical method. In order to facilitate comparison of current and future plasma-based studies to previous serum-based studies, we characterized the relationships between hormone measurements in matched plasma and serum, and found that measurements across matrices are significantly and positively correlated. Lastly, to demonstrate potential applications of this method, we examined how steroid hormone profiles vary by pregnancy, sexual maturity, and stress status - pregnancy was associated with elevated progesterone, adult males had higher testosterone, and capture stress was associated with elevated corticosteroids. Overall, we conclude that this method will enable investigators to more thoroughly and efficiently evaluate steroid hormone homeostasis in bottlenose dolphins compared to immunoassay methods. These methods can potentially be applied to the assessment of sexual maturity/seasonality, pregnancy status, and stress in free-ranging bottlenose dolphins as well as those maintained under human care, and potentially other marine mammals.

Profiles of environmental contaminants in hawksbill turtle egg yolks reflect local to distant pollution sources among nesting beaches in the Yucatán Peninsula, Mexico

Knowledge of spatial variation in pollutant profiles among sea turtle nesting locations is limited. This poses challenges in identifying processes shaping this variability and sets constraints to the conservation management of sea turtles and their use as biomonitoring tools for environmental pollutants. We aimed to increase understanding of the spatial variation in polycyclic aromatic hydrocarbon (PAH), organochlorine pesticide (OCP) and polychlorinated biphenyl (PCB) compounds among nesting beaches. We link the spatial variation to turtle migration patterns and the persistence of these pollutants. Specifically, using gas chromatography, we confirmed maternal transfer of a large number of compounds (n = 68 out of 69) among 104 eggs collected from 21 nests across three nesting beaches within the Yucatán Peninsula, one of the world's most important rookeries for hawksbill turtles (Eretmochelys imbricata). High variation in PAH profiles was observed among beaches, using multivariate correspondence analysis and univariate Peto-Prentice tests, reflecting local acquisition during recent migration movements. Diagnostic PAH ratios reflected petrogenic origins in Celestún, the beach closest to petroleum industries in the Gulf of Mexico. By contrast, pollution profiles of OCPs and PCBs showed high similarity among beaches, reflecting the long-term accumulation of these pollutants at regional scales. Therefore, spatial planning of protected areas and the use of turtle eggs in biomonitoring needs to account for the spatial variation in pollution profiles among nesting beaches.

Exploring the presence of pollutants at sea: Monitoring heavy metals and pesticides in loggerhead turtles (Caretta caretta) from the western Mediterranean

Marine turtles are considered good sentinel species for environmental assessment because of their long lifespan, feeding ecology, habitat use and migratory nature. In the present study, we assessed presence of cadmium, lead and mercury, together with organic pollutants, both in fat and muscle tissue of 25 stranded loggerhead turtles (Caretta caretta) stranded along the Valencian Community coast (East Spain) (43.7±13.5cm). Mean concentrations of Cd, Pb and Hg were 0.04μg/g w.w., 0.09μg/g w.w. and 0.03μg/g w.w. in fat and 0.05μg/g, 0.08μg/g and 0.04μg/g in muscle, respectively. These measures indicate a relatively low mean heavy metal concentration, which may be explained by juvenile size and developmental stage of the turtles analysed. A preliminary non-targeted analysis (using time-of-flight (TOF) technology), made for the first time in marine turtles, allowed to detect 39 different pesticides, most of them previously undetected in this species. Most of the organic substances detected are used in agricultural activities, and the use of 15 of them (38.5%) is not approved in the European Union. Our sample did not show any trend on pollutant contents in relation to turtle size or stranding location, probably because of the high diversity of pollutants found. However, the potential for a positive latitudinal gradient should be explored in future studies due to riverine inputs and high agricultural and industrial activities in the area. Despite the high diversity of pollutants found here, comparative studies of pollutants in other matrices at sea are needed to ascertain whether the loggerhead turtle is a good sentinel of chemical pollution in the western Mediterranean.

Analysis of PFAAs in American alligators part 1: Concentrations in alligators harvested for consumption during South Carolina public hunts

Environmental contamination resulting from the production or release of harmful chemicals can lead to negative consequences for wildlife and human health. Perfluorinated alkyl acids (PFAAs) were historically produced as protective coatings for many household items and currently persist in the environment, wildlife, and humans. PFAAs have been linked to immune suppression, endocrine disruption, and developmental toxicity in wildlife and laboratory studies. This study examines the American alligator, Alligator mississippiensis, as an important indicator of ecosystem contamination and a potential pathway for PFAA exposure in humans. Alligator meat harvested in the 2015 South Carolina (SC) public hunt season and prepared for human consumption was collected and analyzed for PFAAs to determine meat concentrations and relationships with animal body size (total length), sex, and location of harvest. Of the 15 PFAAs analyzed, perfluorooctane sulfonate (PFOS) was found in all alligator meat samples and at the highest concentrations (median 6.73ng/g). No relationship was found between PFAA concentrations and total length or sex. Concentrations of one or all compounds varied significantly across sampling locations, with alligators harvested in the Middle Coastal hunt unit having the highest PFOS concentrations (median 16.0ng/g; p=0.0001). Alligators harvested specifically from Berkley County, SC (located in the Middle Coastal hunt unit) had the highest PFOS concentrations and the greatest number of PFAAs detected (p<0.0001). The site-specific nature of PFAA concentrations in alligator meat observed in this study suggests a source of PFAA contamination in Berkley County, SC.

Perfluorinated alkyl acids in plasma of American alligators (Alligator mississippiensis) from Florida and South Carolina

The present study aimed to quantitate 15 perfluoroalkyl acids (PFAAs) in 125 adult American alligators at 12 sites across the southeastern United States. Of those 15 PFAAs, 9 were detected in 65% to 100% of samples: perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), perfluorododecanoic acid, perfluorotridecanoic acid (PFTriA), perfluorotetradecanoic acid, perfluorohexanesulfonic acid (PFHxS), and perfluorooctane sulfonate (PFOS). Males (across all sites) showed significantly higher concentrations of 4 PFAAs: PFOS (p = 0.01), PFDA (p = 0.0003), PFUnA (p = 0.021), and PFTriA (p = 0.021). Concentrations of PFOS, PFHxS, and PFDA in plasma were significantly different among the sites in each sex. Alligators at both Merritt Island National Wildlife Refuge (FL, USA) and Kiawah Nature Conservancy (SC, USA) exhibited some of the highest PFOS concentrations (medians of 99.5 ng/g and 55.8 ng/g, respectively) in plasma measured to date in a crocodilian species. A number of positive correlations between PFAAs and snout-vent length were observed in both sexes, suggesting that PFAA body burdens increase with increasing size. In addition, several significant correlations among PFAAs in alligator plasma may suggest conserved sources of PFAAs at each site throughout the greater study area. The present study is the first to report PFAAs in American alligators, to reveal potential PFAA hot spots in Florida and South Carolina, and to provide a contaminant of concern when assessing anthropogenic impacts on ecosystem health. Environ Toxicol Chem 2017;36:917-925. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Levels of perfluorinated acids (PFCAs) in different tissues of Lepidochelys olivacea sea turtles from the Escobilla beach (Oaxaca, Mexico)

Lepidochelys olivacea is the most abundant and globally distributed sea turtle species in the world and thus, monitoring this species for persistent organic pollutants, such as perfluorinated chemicals, is fundamental for their protection. This study was the first to evaluate the occurrence of five PFCAs (PFOA, PFNA, PFDA, PFUnA, PFDoA) in liver and blood samples of Olive Ridley turtle population from the Escobilla beach (Oaxaca, Mexico). PFDA and PFUnA were the predominant PFCs in blood samples (detected in 93% and 84% of samples, respectively) and were also present in the highest concentrations. Liver samples showed higher PFCA concentrations than whole blood samples, with PFNA and PFDA the most abundant PFCs congeners in liver samples, detected in 65% and 47% of the samples, respectively. The measured levels of contaminants in the blood samples of Lepidochelys olivacea sea turtles were compared to the levels reported in the literature for other turtle species. While linear significant correlations between PFNA, PFDA and PFUnA concentrations in blood samples and curved carapace lengths were determined, no correlation was found for PFOA, supporting the hypothesis that sea turtles could have a higher ability to eliminate this perfluorinated chemical from their blood than other PFCAs. However, we do not know if the concentrations are species or sampling areas dependent.

Perfluorinated alkyl acids in the plasma of South African crocodiles (Crocodylus niloticus)

Perfluorinated alkyl acids (PFAAs) are environmental contaminants that have been used in many products for over 50 years. Interest and concern has grown since 2000 on the widespread presence of PFAAs, when it was discovered that PFAAs were present in wildlife samples around the northern hemisphere. Since then, several studies have reported PFAAs in wildlife from many locations, including the remote regions of Antarctica and the Arctic. Although there are a multitude of studies, few have reported PFAA concentrations in reptiles and wildlife in the Southern Hemisphere. This study investigated the presence of PFAAs in the plasma of Nile crocodiles (Crocodylus niloticus) from South Africa. Crocodiles were captured from five sites in and around the Kruger National Park, South Africa, and plasma samples examined for PFAAs. Perfluorooctane sulfonate (PFOS) was the most frequent PFAA detected; with median values of 13.5 ng/g wet mass in crocodiles. In addition to PFOS, long chain perfluorinated carboxylic acids were also detected. Correlations between total length and PFAA load were investigated, as were differences in PFAA accumulation between sexes. No correlations were seen between crocodile size, nor were there sex-related differences. Spatial differences were examined and significant differences were observed in samples collected from the different sites (p < 0.05). Flag Boshielo Dam had the highest PFOS measurements, with a median concentration of 50.3 ng/g wet mass, when compared to the other sites (median concentrations at other sites below 14.0 ng/g wet mass). This suggests a point source of PFOS in this area.

Establishment, characterization, and toxicological application of loggerhead sea turtle (Caretta caretta) primary skin fibroblast cell cultures

Pollution is a well-known threat to sea turtles but its impact is poorly understood. In vitro toxicity testing presents a promising avenue to assess and monitor the effects of environmental pollutants in these animals within the legal constraints of their endangered status. Reptilian cell cultures are rare and, in sea turtles, largely derived from animals affected by tumors. Here we describe the full characterization of primary skin fibroblast cell cultures derived from biopsies of multiple healthy loggerhead sea turtles (Caretta caretta), and the subsequent optimization of traditional in vitro toxicity assays to reptilian cells. Characterization included validating fibroblast cells by morphology and immunocytochemistry, and optimizing culture conditions by use of growth curve assays with a fractional factorial experimental design. Two cell viability assays, MTT and lactate dehydrogenase (LDH), and an assay measuring cytochrome P4501A (CYP1A) expression by quantitative PCR were optimized in the characterized cells. MTT and LDH assays confirmed cytotoxicity of perfluorooctanoic acid at 500 μM following 72 and 96 h exposures while CYP1A5 induction was detected after 72 h exposure to 0.1-10 μM benzo[a]pyrene. This research demonstrates the validity of in vitro toxicity testing in sea turtles and highlights the need to optimize mammalian assays to reptilian cells.

Fate and effects of poly- and perfluoroalkyl substances in the aquatic environment: a review

Polyfluoroalkyl and perfluoroalkyl substances (PFASs) are distributed ubiquitously in the aquatic environment, which raises concern for the flora and fauna in hydrosystems. The present critical review focuses on the fate and adverse effects of PFASs in the aquatic environment. The PFASs are continuously emitted into the environment from point and nonpoint sources such as sewage treatment plants and atmospheric deposition, respectively. Although concentrations of single substances may be too low to cause adverse effects, their mixtures can be of significant environmental concern. The production of C8 -based PFASs (i.e., perfluorooctane sulfonate [PFOS] and perfluorooctanoate [PFOA]) is largely phased out; however, the emissions of other PFASs, in particular short-chain PFASs and PFAS precursors, are increasing. The PFAS precursors can finally degrade to persistent degradation products, which are, in particular, perfluoroalkane sulfonates (PFSAs) and perfluoroalkyl carboxylates (PFCAs). In the environment, PFSAs and PFCAs are subject to partitioning processes, whereby short-chain PFSAs and PFCAs are mainly distributed in the water phase, whereas long-chain PFSAs and PFCAs tend to bind to particles and have a substantial bioaccumulation potential. However, there are fundamental knowledge gaps about the interactive toxicity of PFAS precursors and their persistent degradation products but also interactions with other natural and anthropogenic stressors. Moreover, because of the continuous emission of PFASs, further information about their ecotoxicological potential among multiple generations, species interactions, and mixture toxicity seems fundamental to reliably assess the risks for PFASs to affect ecosystem structure and function in the aquatic environment.

Perfluoroalkyl acids in subarctic wild male mink (Neovison vison) in relation to age, season and geographical area

This study investigates the influence of biological and environmental factors on the concentrations of perfluoroalkyl acids (PFAAs) in a top predator; the American mink. Perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) with C8-C13 perfluorinated carbon chains were analyzed in livers from wild male mink liver (n=101) from four areas in Sweden representing two inland environments (rural and highly anthropogenic, respectively) and two different coastal environments. Mean PFOS concentrations were 1250ng/g wet weight and some mink from the urban inland area had among the highest PFOS concentrations ever recorded in mink (up to 21 800ng/g wet weight). PFBS was detected in 89% of the samples, but in low concentrations (mean 0.6ng/g ww). There were significant differences in PFAA concentrations between the geographical areas (p<0.001-0.01). Age, body condition and body weight did not influence the concentrations significantly, but there was a seasonal influence on the concentrations of perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnDA) (p<0.01 and p<0.05, respectively), with lower concentrations in autumn samples than in samples taken in the winter and spring. It is thus recommended to take possible seasonal differences into account when using mink exposure data. The overall results suggest that the mink is a suitable sentinel species for assessing and monitoring environmental levels of PFAAs.