Impacts of Deepwater Horizon crude oil exposure on adult mahi‐mahi (Coryphaena hippurus) swim performance

Abstract

The temporal and geographic attributes of the Deepwater Horizon incident in 2010 likely exposed pelagic game fish species, such as mahi-mahi, to crude oil. Although much of the research assessing the effects of the spill has focused on early life stages of fish, studies examining whole-animal physiological responses of adult marine fish species are lacking. Using swim chamber respirometry, the present study demonstrates that acute exposure to a sublethal concentration of the water accommodated fraction of Deepwater Horizon crude oil results in significant swim performance impacts on young adult mahi-mahi, representing the first report of acute sublethal toxicity on adult pelagic fish in the Gulf of Mexico following the spill. At an exposure concentration of 8.4 ± 0.6 µg L sum of 50 selected polycyclic aromatic hydrocarbons (PAHs; mean of geometric means ± standard error of the mean), significant decreases in the critical and optimal swimming speeds of 14% and 10%, respectively (p < 0.05), were observed. In addition, a 20% reduction in the maximum metabolic rate and a 29% reduction in aerobic scope resulted from exposure to this level of ΣPAHs. Using environmentally relevant crude oil exposure concentrations and a commercially and ecologically valuable Gulf of Mexico fish species, the present results provide insight into the effects of the Deepwater Horizon oil spill on adult pelagic fish. Environ Toxicol Chem 2016;35:2613-2622. © 2016 SETAC.

Mahi‐mahi (Coryphaena hippurus) life development: morphological, physiological, behavioral and molecular phenotypes

“…In summary, mahi are large pelagic fish ( Figure 1Z) with high energetic requirements necessary to maintain their "high-performance" lifestyle. 7,23,28,32,42,45 Their physiological and metabolic capacities are therefore elevated for the increased supply of energy, oxygen, and substrate needed for swimming performance and routine activities 23,28 compared to those of more established fish models (eg, killifish, medaka, Zebrafish). From a developmental perspective, mahi share numerous physiological and behavioral landmarks with others pelagic fish (tunas or billfishes) as a result of a similar lifestyle.…”

“…Indeed, during the last few decades, mahi has become an emergent model for examining population genetics, developmental physiology, metabolic responses, nutritional physiology, egg and larval performance over time, and climate change effects . Mahi have also been studied extensively regarding the impact of environmental toxicants . The emergence of this model fish has been accelerated by the need to develop more sophisticated scientific approaches for understanding the impact of environmental stressors, especially the impacts of the Deepwater Horizon Oil spill in 2010.…”

“…15,16 Mahi have also been studied extensively regarding the impact of environmental toxicants. [17][18][19][20][21][22][23][24][25][26][27][28][29][30] The emergence of this model fish has been accelerated by the need to develop more sophisticated scientific approaches for understanding the impact of environmental stressors, especially the impacts of the Deepwater Horizon Oil spill in 2010. Immediate mortality or fitness declines have been shown in fin fish populations as a result of pollution exposure (see numerous chapters in Burggren and Dubansky 31 ).…”

Heart Performance Determination by Visualization in Larval Fishes: Influence of Alternative Models for Heart Shape and Volume

“…Stroke volume and ultimately cardiac output are critical for health and normal development (Burggren and Bagatto, 2008; Burggren et al, in press). Understanding the heart's mechanics is crucial for clinical or environmental research because many pathologies are strongly correlated with cardiac failure (Incardona et al, 2004, 2009; Nelson et al, 2016; Sørhus et al, 2016; Stieglitz et al, 2016). These impairments in cardiac function are often accompanied by accumulation of fluid (edema), as well as craniofacial and body defects (Incardona and Scholz, 2016; Sørhus et al, 2016).…”

“…These impairments in cardiac function are often accompanied by accumulation of fluid (edema), as well as craniofacial and body defects (Incardona and Scholz, 2016; Sørhus et al, 2016). Physiological effects may appear as well, such as the decreased swimming performance in mahi-mahi ( Coryphaena hippurus ) associated with a reduction in cardiac contractility and blood ejection (Mager et al, 2014; Nelson et al, 2016; Stieglitz et al, 2016). No doubt, cardiac function is key factor to fish survival, and understanding how cardiac output develops in larval fishes will provide a powerful insight to physiological conditions of developing larvae as they face environmental challenges.…”