A review of the toxicology of oil in vertebrates : what we have learned following the Deepwater Horizon oil spill

This research was made possible by a grant from The Gulf of Mexico Research Initiative. This publication is UMCES contribution No. 6045 and Ref. No. [UMCES] CBL 2022-008. This is National Marine Mammal Foundation Contribution #314 to peer-reviewed scientific literature.In the wake of the Deepwater Horizon (DWH) oil spill, a number of government agencies, academic institutions, consultants, and nonprofit organizations conducted lab- and field-based research to understand the toxic effects of the oil. Lab testing was performed with a variety of fish, birds, turtles, and vertebrate cell lines (as well as invertebrates); field biologists conducted observations on fish, birds, turtles, and marine mammals; and epidemiologists carried out observational studies in humans. Eight years after the spill, scientists and resource managers held a workshop to summarize the similarities and differences in the effects of DWH oil on vertebrate taxa and to identify remaining gaps in our understanding of oil toxicity in wildlife and humans, building upon the cross-taxonomic synthesis initiated during the Natural Resource Damage Assessment. Across the studies, consistency was found in the types of toxic response observed in the different organisms. Impairment of stress responses and adrenal gland function, cardiotoxicity, immune system dysfunction, disruption of blood cells and their function, effects on locomotion, and oxidative damage were observed across taxa. This consistency suggests conservation in the mechanisms of action and disease pathogenesis. From a toxicological perspective, a logical progression of impacts was noted: from molecular and cellular effects that manifest as organ dysfunction, to systemic effects that compromise fitness, growth, reproductive potential, and survival. From a clinical perspective, adverse health effects from DWH oil spill exposure formed a suite of signs/symptomatic responses that at the highest doses/concentrations resulted in multi-organ system failure.Publisher PDFPeer reviewe

A COMPARATIVE ASSESSMENT OF AZINPHOSMETHYL BIOACCUMULATION AND TOXICITY IN TWO ESTUARINE MEIOBENTHIC HARPACTICOID COPEPODS

Abstract—Aqueous, pore-water, and whole-sediment bioassays were conducted with meiobenthic copepods with different infaunal lifestyles to assess the acute and chronic toxicity of the organophosphorous pesticide azinphosmethyl (APM) and its bioaccumulation potential in sediments. Biota sediment accumulation factors were an order of magnitude higher for the deeper burrowing Amphiascus tenuiremis (26.6) than the epibenthic Microarthridion littorale (2.2). The female A. tenuiremis APM median lethal concentration (LC50; 3.6 mg/L) was twice the male LC50 (1.8 mg/L), in straight seawater exposures, and nearly 20 % higher than males in whole-sediment exposures (540 vs 456 ng/g dry weight). Amphiascus tenuiremis were 17 times more sensitive to sediment-associated APM than M. littorale. In pore-water–only exposures, the adult mixed-sex A. tenuiremis LC50 (5.0 mg/L) was nearly twice the seawater mixed-sex LC50 (2.7 mg/L). Dissolved organic carbon in pore water was five times higher (20 mg/L) than in seawater-only exposures (4 mg/L). Differences in acute toxicity within exposure media were driven by species- and sex-specific differences in lipid content. Amphiascus tenuiremis likely experienced greater exposure to sediment-associated toxicants via longer periods of direct contact with pore water than M. littorale and, therefore, exhibited correspondingly higher bioaccumulation and acute toxicity. Copepod reproduction was significantly reduced (.60%) in 14-d sediment culture exposures at sublethal APM levels, suggestin