Mercury (Hg) is a contaminant of global concern due to its damaging toxicological effects on organisms. For the vulnerable Dusky Grouper (Epinephelus marginatus) off the coast of Brazil, we investigated: i) spatial patterns in muscle tissue total mercury (THg) contamination; ii) the relationship between muscle THg concentrations and total length iii) the relationship between muscle THg and stable isotopes; and iv) THg concentrations among muscle, liver, and ovary tissues. Out of 134 fish sampled, 21.
View Article and Find Full Text PDFThe global sequencing of microRNA (miRNA; miR) and integration to downstream mRNA expression profiles in early life stages (ELS) of fish following exposure to crude oil determined consistently dysregulated miRNAs regardless of the oil source or fish species. The overlay of differentially expressed miRNAs and mRNAs into in silico software determined that the key roles of these miRNAs were predicted to be involved in cardiovascular, neurological and visually-mediated pathways. Of these, altered expression of miRNAs, miR-203a and miR-34b were predicted to be primary targets of crude oil.
View Article and Find Full Text PDFPersistent organic pollutants (POPs) are highly lipophilic compounds that accumulate at increased concentrations in high tropic level organisms like marine mammals. Marine mammals' reliance on blubber makes them susceptible to accumulating POPs at potentially toxic concentrations. In this study, we analyzed POP concentrations, (polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and methoxylated-BDE (MeOBDE), in the blubber of 16 subsistence harvested sub-adult, male northern fur seals as well as assessed changes in mRNA gene expression of nine relevant biomarkers including the aryl hydrocarbon receptor, thyroid receptor-α, and adiponectin.
View Article and Find Full Text PDFUltraviolet (UV) radiation can significantly increase the toxicity of polycyclic aromatic hydrocarbons (PAHs) in crude oil to early life stage (ELS) fishes through photo-induced /photo-enhanced toxicity. However, little is known about the sub-lethal effects and mechanisms of photo-induced PAH toxicity in ELS fishes. The present study investigated apoptosis and global transcriptomic effects in larval red drum (Sciaenops ocellatus) (24-72 h post-fertilization) following co-exposure to oil (0.
View Article and Find Full Text PDFCrude oil has multiple toxic effects in fish, particularly during their early life stages. Recent transcriptomics studies have highlighted a potential effect on cholesterol homeostasis and biosynthesis, but have not investigated effects on steroid hormones, which are biosynthetically downstream metabolites of cholesterol. We exposed zebrafish (Danio rerio) embryos and larvae to 3 concentrations of a high energy water accommodated fraction (HEWAF) of crude oil and measured effects on cholesterol and steroid hormones at 48 and 96 h post fertilization (hpf).
View Article and Find Full Text PDFJ Toxicol Environ Health B Crit Rev
November 2021
In the aquatic environment, ubiquitous natural factors such as ultraviolet light (UV) and dissolved organic carbon (DOC) are likely to influence crude oil toxicity. The present study examined the interactive effects of DOC, UV, and DOC-UV co-exposure on the acute toxicity of Deepwater Horizon crude oil in larval red drum (Sciaenops ocellatus). Although DOC alone did not influence crude oil toxicity, it mildly reduced UV photo-enhanced toxicity.
View Article and Find Full Text PDFBenthic organisms may be exposed to polycyclic aromatic hydrocarbons (PAHs) in marine sediments as the result of oil spills. PAH photoinduced toxicity, which has been documented in a wide range of early life stage (ELS) aquatic biota, is a phenomenon by which ultraviolet (UV) radiation potentiates the toxicity of photodynamic PAHs (often leading to mortality). Fiddler crabs ) are important ecosystem engineers that influence biogeochemical cycles via burrowing.
View Article and Find Full Text PDFPolycyclic aromatic hydrocarbons (PAHs) present in crude oil are known to impair visual development in fish. However, the underlying mechanism of PAH-induced toxicity to the visual system of fish is not understood. Embryonic zebrafish () at 4 h post fertilization were exposed to weathered crude oil and assessed for visual function using an optokinetic response, with subsequent samples taken for immunohistochemistry and gene expression analysis.
View Article and Find Full Text PDFComp Biochem Physiol C Toxicol Pharmacol
April 2020
Anthracene is a highly toxic polycyclic aromatic hydrocarbon (PAH), and its toxicity is increased 8-fold after compounding exposure to UV radiation. Exposure to either the parent or photo-modified compound has been shown to cause increases in reactive oxygen species (ROS) production and lipid peroxidation. Since the majority of ROS production occurs within mitochondria, we investigated simultaneous mitochondrial respiration and ROS production in the gills of sheepshead minnows (Cyprinodon variegatus) acutely (48 h) exposed to anthraquinone (40 μg l).
View Article and Find Full Text PDFSynthetic sex steroids, like the synthetic progestin norethindrone (NET), can affect a wide variety of biological processes via highly conserved mechanisms. NET is prevalent in surface waters, yet the sub-lethal effects of NET exposure are not are net yet well characterized in aquatic biota. A few targeted gene expression and behavioral studies have concluded that NET affects the vision of adult fish; however, early life stage (ELS) fish are often more sensitive to contaminants.
View Article and Find Full Text PDFThe corrections are: In the 2nd sentence of the Statistical Analyses section, the current sentence lacks important statistical assumption wording.
View Article and Find Full Text PDFBackground: Mahi-mahi (Coryphaena hippurus) is a commercially and ecologically important fish species that is widely distributed in tropical and subtropical waters. Biological attributes and reproductive capacities of mahi-mahi make it a tractable model for experimental studies. In this study, life development of cultured mahi-mahi from the zygote stage to adult has been described.
View Article and Find Full Text PDFMercury (Hg) deposited into aquatic sediments can be converted into the more toxic methylmercury (MeHg) by microbial activity. Atlantic stingrays (Hypanus sabinus) are an estuarine and nearshore species found in coastal regions of the western North Atlantic, occurring in multiple habitat types, and feeding mainly on benthic invertebrates. Mercury dynamics and speciation in stingrays have not been well examined.
View Article and Find Full Text PDFThis editorial introduces the issue of selected papers that were presented at the third International Conference on Environmental Pollution, Restoration, and Management in Quy Nhon, Vietnam on 6-10 March 2017. While environmental problems caused by diverse municipal, industrial, and other economic development activities continue to increase in many Asian countries, public awareness about environmental management for public health and the environment remain at levels that favor accepting environmental degradation and impacts for tradeoffs with economic values. This special issue resulted from a conference that was organized to bringing scientists from developed and developing countries to Vietnam to share experiences, discuss environmental problems, and enhance future collaborations for research and training in support of better management plans for the environment and health.
View Article and Find Full Text PDFPolycyclic aromatic hydrocarbons (PAHs) present in crude oil have been shown to cause the dysregulation of genes important in eye development and function, as well as morphological abnormalities of the eye. However, it is not currently understood how these changes in gene expression are manifested as deficits in visual function. Embryonic red drum (Sciaenops ocellatus) and sheepshead minnow (Cyprinodon variegatus) were exposed to water accommodated fractions (WAFs) of weathered crude oil and assessed for visual function using an optomotor response assay in early life-stage larvae, with subsequent samples taken for histological analysis of the eyes.
View Article and Find Full Text PDFMercury is a global contaminant, which may be microbially transformed into methylmercury (MeHg), which bioaccumulates. This results in potentially toxic body burdens in high trophic level organisms in aquatic ecosystems and maternal transfer to offspring. We previously demonstrated effects on developing fish including hyperactivity, altered time-to-hatch, reduced survival, and dysregulation of the dopaminergic system.
View Article and Find Full Text PDFThe toxicity of some polycyclic aromatic hydrocarbons (PAHs) increases with ultraviolet (UV) radiation. The intensity of UV radiation varies within aquatic ecosystems, potentially providing reprieves during which tissue repair may occur. Transient/short-term PAH exposure prior to UV exposure may initiate metabolism/clearance, potentially affecting outcomes.
View Article and Find Full Text PDFPolybrominated diphenyl ethers (PBDEs) are highly lipophilic components of brominated flame retardants that are environmentally persistent and bioaccumulate. PBDEs are taken up from the gastrointestinal tract and accumulate mainly in fat depots and liver tissues. Seal species inhabiting Arctic and sub-Arctic regions can have upwards of 30% of their body mass composed of blubber.
View Article and Find Full Text PDFMillions of barrels of oil were released into the Gulf of Mexico following the 2010 explosion of the Deepwater Horizon oil rig. Polycyclic aromatic hydrocarbons (PAHs) are toxic components of crude oil, which may become more toxic in the presence of ultraviolet (UV) radiation, a phenomenon known as photo-induced toxicity. The Deepwater Horizon spill impacted offshore and estuarine sites, where biota may be co-exposed to UV and PAHs.
View Article and Find Full Text PDFThe 2010 explosion of the Deepwater Horizon (DWH) oil rig led to the release of millions of barrels of oil in the Gulf of Mexico. Oil in aquatic ecosystems exerts toxicity through multiple mechanisms, including photo-induced toxicity following co-exposure with UV radiation. The timing and location of the spill coincided with both fiddler crab reproduction and peak yearly UV intensities, putting early life stage fiddler crabs at risk of injury due to photo-induced toxicity.
View Article and Find Full Text PDFSome polycyclic aromatic hydrocarbons (PAHs), components of crude oil, are known to cause increased toxicity when organisms are co-exposed with ultraviolet radiation, resulting in photo-induced toxicity. The photodynamic characteristics of some PAHs are of particular concern to places like Australia with high ultraviolet radiation levels. The objective of the present study was to characterize the photo-induced toxicity of an Australian North West Shelf oil to early life stage yellowtail kingfish (Seriola lalandi) and black bream (Acanthopagrus butcheri).
View Article and Find Full Text PDFFlight within degraded visual conditions is a great challenge to pilots of rotary-wing craft. Environmental cues typically used to guide interpretation of speed, location and approach can become obscured, forcing the pilots to rely on data available from in-cockpit instrumentation. To ease the task of flight during degraded visual conditions, pilots require easy access to flight critical information.
View Article and Find Full Text PDFThe Deepwater Horizon oil spill occurred in the summer of 2010 and coincided with the spawning window of the ecologically and economically important pelagic fish mahi-mahi (Coryphaena hippurus). During summer months, early life stage mahi-mahi were likely also exposed to other naturally occurring stressors such as increased temperature and ultraviolet radiation (UV). Previous research has shown that co-exposure to oil and additional natural stressors can affect the timing and duration of negative buoyancy in mahi-mahi embryos.
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