Multiple lines of evidence at whole animal, cellular and molecular levels implicate polycyclic aromatic compounds (PACs) with three rings as drivers of crude oil toxicity to developing fish. Phenanthrene (P0) and its alkylated homologs (C1- through C4-phenanthrenes) comprise the most prominent subfraction of tricyclic PACs in crude oils. Among this family, P0 has been studied intensively, with more limited detail available for the C4-phenanthrene 1-methyl-7-isopropyl-phenanthrene (1-M,7-IP, or retene).
View Article and Find Full Text PDFPacific herring (), a cornerstone of marine food webs, generally spawn on marine macroalgae in shallow nearshore areas that are disproportionately at risk from oil spills. Herring embryos are also highly susceptible to toxicity from chemicals leaching from oil stranded in intertidal and subtidal zones. The water-soluble components of crude oil trigger an adverse outcome pathway that involves disruption of the physiological functions of cardiomyocytes in the embryonic herring heart.
View Article and Find Full Text PDFAs the human population of western North America continues to expand, widespread patterns of urban growth pose increasingly existential threats to certain wild stocks of Pacific salmon and steelhead (Oncorhynchus sp.). Rainfall previously absorbed into the soils of forests and grasslands falls instead on pavement and other hardened surfaces.
View Article and Find Full Text PDFAtlantic haddock (Melanogrammus aeglefinus) embryos bind dispersed crude oil droplets to the eggshell and are consequently highly susceptible to toxicity from spilled oil. We established thresholds for developmental toxicity and identified any potential long-term or latent adverse effects that could impair the growth and survival of individuals. Embryos were exposed to oil for eight days (10, 80 and 300 μg oil/L, equivalent to 0.
View Article and Find Full Text PDFJ Toxicol Environ Health B Crit Rev
November 2021
There is a growing awareness that transient, sublethal embryonic exposure to crude oils cause subtle but important forms of delayed toxicity in fish. While the precise mechanisms for this loss of individual fitness are not well understood, they involve the disruption of early cardiogenesis and a subsequent pathological remodeling of the heart much later in juveniles. This developmental cardiotoxicity is attributable, in turn, to the inhibitory actions of crude oil-derived mixtures of polycyclic aromatic compounds (PACs) on specific ion channels and other proteins that collectively drive the rhythmic contractions of heart muscle cells via excitation-contraction coupling.
View Article and Find Full Text PDFA fundamental understanding of the impact of petrochemicals and other stressors on marine biodiversity is critical for effective management, restoration, recovery, and mitigation initiatives. As species-specific information on levels of petrochemical exposure and toxicological response are lacking for the majority of marine species, a trait-based assessment to rank species vulnerabilities to petrochemical activities in the Gulf of Mexico can provide a more comprehensive and effective means to prioritize species, habitats, and ecosystems for improved management, restoration and recovery. To initiate and standardize this process, we developed a trait-based framework, applicable to a wide range of vertebrate and invertebrate species, that can be used to rank relative population vulnerabilities of species to petrochemical activities in the Gulf of Mexico.
View Article and Find Full Text PDFUnderstanding how aquatic organisms respond to complex chemical mixtures remains one of the foremost challenges in modern ecotoxicology. Although oil spills are typically high-profile disasters that release hundreds or thousands of chemicals into the environment, there is growing evidence for a common adverse outcome pathway (AOP) for the vulnerable embryos and larvae of fish species that spawn in oiled habitats. Molecular initiating events involve the disruption of excitation-contraction coupling in individual cardiomyocytes, which then dysregulate the form and function of the embryonic heart.
View Article and Find Full Text PDFCardiac remodeling results from both physiological and pathological stimuli. Compared with mammalian hearts, fish hearts show a broader array of remodeling changes in response to environmental influences, providing exceptional models for dissecting the molecular and cellular bases of cardiac remodeling. We recently characterized a form of pathological remodeling in juvenile pink salmon () in response to crude oil exposure during embryonic cardiogenesis.
View Article and Find Full Text PDFAs Arctic ice recedes, future oil spills pose increasing risk to keystone species and the ecosystems they support. We show that Polar cod (Boreogadus saida), an energy-rich forage fish for marine mammals, seabirds, and other fish, are highly sensitive to developmental impacts of crude oil. Transient oil exposures ≥300 μg/L during mid-organogenesis disrupted the normal patterning of the jaw as well as the formation and function of the heart, in a manner expected to be lethal to post-hatch larvae.
View Article and Find Full Text PDFThe potential bioavailability of toxic chemicals from oil spills to water column organisms such as fish embryos may be influenced by physical dispersion along an energy gradient. For example, a surface slick with minimal wave action (low energy) could potentially produce different toxic effects from high energy situations such as pressurized discharge from a blown wellhead. Here we directly compared the toxicity of water accommodated fractions (WAFs) of oil prepared with low and high mixing energy (LEWAFs and HEWAFs, respectively) using surface oil samples collected during the 2010 Deepwater Horizon spill, and embryos of a representative nearshore species, red drum (Sciaenops ocellatus).
View Article and Find Full Text PDFAdult coho salmon (Oncorhynchus kisutch) prematurely die when they return from the ocean to spawn in urban watersheds throughout northwestern North America. The available evidence suggests the annual mortality events are caused by toxic stormwater runoff. The underlying pathophysiology of the urban spawner mortality syndrome is not known, and it is unclear whether closely related species of Pacific salmon are similarly at risk.
View Article and Find Full Text PDFArch Environ Contam Toxicol
July 2017
With major oil spills in Korea, the United States, and China in the past decade, there has been a dramatic increase in the number of studies characterizing the developmental toxicity of crude oil and its associated polycyclic aromatic compounds (PACs). The use of model fish species with associated tools for genetic manipulation, combined with high throughput genomics techniques in nonmodel fish species, has led to significant advances in understanding the cellular and molecular bases of functional and morphological defects arising from embryonic exposure to crude oil. Following from the identification of the developing heart as the primary target of crude oil developmental toxicity, studies on individual PACs have revealed a diversity of cardiotoxic mechanisms.
View Article and Find Full Text PDFThe impact of crude oil pollution on early life stages (ELS) of fish, including larvae and embryos, has received considerable attention in recent years. Of the organic components present in crude oil, polycyclic aromatic hydrocarbons (PAHs) are considered the main class of compounds responsible for toxic effects in marine organisms. Although evidence suggests that they are more toxic, alkylated PAHs remain much less studied than their unsubstituted congeners.
View Article and Find Full Text PDFThe Deepwater Horizon disaster drew global attention to the toxicity of crude oil and the potential for adverse health effects amongst marine life and spill responders in the northern Gulf of Mexico. The blowout released complex mixtures of polycyclic aromatic hydrocarbons (PAHs) into critical pelagic spawning habitats for tunas, billfishes, and other ecologically important top predators. Crude oil disrupts cardiac function and has been associated with heart malformations in developing fish.
View Article and Find Full Text PDFCrude oil spills are a worldwide ocean conservation threat. Fish are particularly vulnerable to the oiling of spawning habitats, and crude oil causes severe abnormalities in embryos and larvae. However, the underlying mechanisms for these developmental defects are not well understood.
View Article and Find Full Text PDFRecent studies have shown that crude oil exposure affects cardiac development in fish by disrupting excitation-contraction (EC) coupling. We previously found that eggs of Atlantic haddock (Melanogrammus aeglefinus) bind dispersed oil droplets, potentially leading to more profound toxic effects from uptake of polycyclic aromatic hydrocarbons (PAHs). Using lower concentrations of dispersed crude oil (0.
View Article and Find Full Text PDFThe developing fish heart is vulnerable to a diverse array of toxic chemical contaminants in freshwater, estuarine, and marine habitats. Globally occurring examples of cardiotoxic agents include dioxins, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The disruption of cardiac function during the process of heart morphogenesis can lead to adverse outcome pathways (AOPs) that can negatively affect fish survival at hatching as well as later life stages.
View Article and Find Full Text PDFGadiforms such as Atlantic haddock comprise some of the world's most economically important fisheries. Understanding the early life history of these fish is a prerequisite for predicting effects of a changing environment and increased human activities. Robust assessment of the effects of environmental impacts on the embryos of non-model vertebrates is hampered by a lack of molecular resources and detailed knowledge regarding the regulation of genes and pathways in early development.
View Article and Find Full Text PDFUrban stormwater runoff is a globally significant threat to the ecological integrity of aquatic habitats. Green stormwater infrastructure methods such as bioretention are increasingly used to improve water quality by filtering chemical contaminants that may be harmful to fish and other species. Ubiquitous examples of toxics in runoff from highways and other impervious surfaces include polycyclic aromatic hydrocarbons (PAHs).
View Article and Find Full Text PDFCrude oils from distinct geological sources worldwide are toxic to developing fish hearts. When oil spills occur in fish spawning habitats, natural resource injury assessments often rely on conventional morphometric analyses of heart form and function. The extent to which visible indicators correspond to molecular markers for cardiovascular stress is unknown for pelagic predators from the Gulf of Mexico.
View Article and Find Full Text PDFCoal tar sealcoats applied to asphalt surfaces in North America, east of the Continental Divide, are enriched in petroleum-derived compounds, including polycyclic aromatic hydrocarbons (PAHs). The release of PAHs and other chemicals from sealcoat has the potential to contaminate nearby water bodies, reducing the resiliency of aquatic communities. Despite this, relatively little is known about the aquatic toxicology of sealcoat-derived contaminants.
View Article and Find Full Text PDFTo better understand the impact of the Deepwater Horizon (DWH) incident on commercially and ecologically important pelagic fish species, a mahi-mahi spawning program was developed to assess the effect of embryonic exposure to DWH crude oil with particular emphasis on the effects of weathering and dispersant on the magnitude of toxicity. Acute lethality (96 h LC50) ranged from 45.8 (28.
View Article and Find Full Text PDFInterspecific difference in the developmental toxicity of crude oil to embryonic fish allows the prediction of injury extent to a number of resident fish species in oil spill sites. This study clarifies the comparative developmental effects of Iranian heavy crude oil (IHCO) on the differences of biouptake and toxic sensitivity between embryonic spotted sea bass (Lateolabrax maculates) and olive flounder (Paralichthys olivaceus). From 24 h after exposure to IHCO, several morphological defects were observed in both species of embryonic fish, including pericardial edema, dorsal curvature of the trunk, developmental delay, and reduced finfolds.
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