Exposure to Crude Oil from the Deepwater Horizon Oil Spill Impairs Oil Avoidance Behavior without Affecting Olfactory Physiology in Juvenile Mahi-Mahi (Coryphaena hippurus)

Abstract

The understanding of the detection threshold and behavioral response of fishes in response to crude oil is critical to predicting the effects of oil spills on wild fish populations. The Deepwater Horizon oil spill released approximately 4.9 million barrels of crude oil into the northern Gulf of Mexico in 2010, overlapping spatially and temporally with the habitat of many pelagic fish species. Yet, it is unknown whether highly migratory species, such as mahimahi (Coryphaena hippurus), might detect and avoid oil contaminated waters. We tested the ability of control and oilexposed juvenile mahi-mahi (15−45 mm) to avoid two dilutions of crude oil in a two-channel flume. Control fish avoided the higher concentration (27.1 μg/L Σ 50 PAH), while oilexposed (24 h, 18.0 μg/L Σ 50 PAH) conspecifics did not. Electro-olfactogram (EOG) data demonstrated that both control and oil-exposed (24 h, 14.5 μg/L Σ 50 PAH) juvenile mahi-mahi (27−85 mm) could detect crude oil as an olfactory cue and that oilexposure did not affect the EOG amplitude or duration in response to oil or other cues. These results show that a brief oil exposure impairs the ability of mahi-mahi to avoid oil and suggests that this alteration likely results from injury to higher order central nervous system processing rather than impaired olfactory physiology.

Previous oil exposure alters oil avoidance behavior in a common marsh fish, the Gulf KillifishFundulus grandis

“…Previous exposure to oil is known to have many negative consequences for individuals. For example, unexposed mahi-mahi avoided higher concentrations of water accommodated fraction of oil, but exposed individuals demonstrated a lack of response (Schlenker et al 2019a). Moreover, damage to the higher order central nervous system processing was implicated in this decreased oil avoidance behavior.…”

“…Fishes have strong behavioral responses to crude oil contamination (Weis et al 2001, Martin 2017a, Schlenker 2019a. Freshwater fishes such as fathead minnows Pimephales promelas (Farr et al 1995), rainbow trout Oncorhynchus mykiss (Carr et al 1990), pink salmon fry Oncorhynchus gorbuscha (Rice 1973), Caspian roach Rutilus caspicus (Lari et al 2015), and striped bass Morone saxatilis (Carr et al 1990) avoid hydrocarbon contaminated areas, albeit at different thresholds and concentrations.…”

“…Estuarine and marine fishes such as flatfishes (Moles et al 1994), juvenile spot Leiostomus xanthurus (Hinkle-Conn et al 1998), European seabass Dicentrarchus labrax (Claireaux et al 2018), and mahi-mahi Coryphaena hippurus (Schlenker 2019a) all respond behaviorally to avoid the toxic chemical contaminants found in petroleum hydrocarbons.…”

“…After oil exposure, bicolor damselfish Stegastes partitus showed a reduction in the response to conspecific alarm cues (Schlenker et al 2019b). This damage to olfactory mechanisms or central nervous processing may further reduce organism's capacity to detect and respond to oil contamination (sensu Schlenker et al 2019a). Here, we present the result of a series of experiments to test the effects of previous exposure on oilcontaminated sediment avoidance in salt marsh fish.…”

Previous oil exposure alters Gulf KillifishFundulus grandisoil avoidance behavior

“…Fish behavior is also known to be affected by chemical pollutants (Saaristo et al, 2018;Jacquin et al, 2020). Diverse taxonomic groups have demonstrated strong behavioral responses to acute crude oil contamination (Weis et al, 2001;Martin, 2017;Schlenker et al, 2019a). Freshwater fishes such as fathead minnows Pimephales promelas (Farr, Chabot & Taylor, 1995), rainbow trout Oncorhynchus mykiss (Carr et al, 1990), pink salmon fry Oncorhynchus gorbuscha (Rice, 1973), Caspian roach Rutilus caspicus (Lari et al, 2015), and striped bass Morone saxatilis (Carr et al, 1990) avoid hydrocarbon contaminated areas, albeit at different thresholds and concentrations.…”