Abstract:

Fish were exposed to four different concentrations of oil utilizing the Louisiana Universities Marine Consortium (LUMCON) saltmarsh mesocosm facility in Cocodrie, Louisiana (twelve hydrologically-isolated mesocosm tanks planted with Spartina alterniflora and exposed to experimental oiling: control/no oil (0.0 L oil m-2), low (0.1 L oil m-2), medium (0.5 L oil m-2), and high (3.0 L oil m-2)). Fish were then removed and used in trials to determine how previous exposure impacted oil avoidance behavior. Using 38-L tanks with oil sediments on one side and unoiled on the other, fish occupancy patterns were observed. Oiled sediments were randomized and included oil at a range of concentrations (low: 10 mL oil/L, medium: 20 mL oil/L, or high: 40 mL oil/L). Observations of fish location in the tank were made for a period of 10 minutes and the proportion of time spent in oil and no oil sections of the tank were recorded.

Suggested Citation:

Martin, C.W., Roberts, B.J.. 2020. Laboratory experiments to determine effects of previous exposure to oil on Fundulus grandis avoidance behavior. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-3qjh-2f11

Publications:

Martin, C. W., McDonald, A. M., Rieucau, G., & Roberts, B. J. (2020). Previous oil exposure alters oil avoidance behavior in a common marsh fish, the Gulf Killifish Fundulus grandis. doi:10.1101/2020.06.15.152413

Purpose:

This work builds on a previous study documenting oil avoidance behavior by determining variability in this response to different previous exposures. By giving organisms a choice between oil-contaminated and clean sediments, this work is integral in determining if fishes have the capacity to detect and avoid oil and how this may change in response to oiled conditions. Results are critical to understanding the resiliency of marsh organisms to anthropogenic disasters such as oil spills and are essential for the continued successful management of living, motile resources such as marsh nekton.

Data Parameters and Units:

Treatment-Previous Exposure: indicates the level of previous exposure (control, low, medium, or high) that fish were exposed to; Comparison-Oil Used in Preference Test: Refers to the relative oil concentration used in the preference experiments (Low, Medium, High); Proportion of Time in Oil: Proportion calculated from observations of location preference made every 30 seconds for 10 minute trial duration divided by total number of observations; Proportion of Time in No Oil: Proportion calculated from observations of location preference made every 30 seconds for 10 minute trial duration divided by total number of observations.

Methods:

Fundulus were collected with minnow traps at the marsh edge near the LUMCON dock and placed in holding tanks for 2 days before transferring to the mesocosms. After exposure duration of 10-14 days, fish were removed using dip nets and held in aerated 19-L buckets until use in the preference experiments. Trials were conducted in 38-L tanks, one for each comparison (no oil vs. low oil, no oil vs. medium oil, no oil vs. high oil). Washed, coarse sand was mixed homogenously with the treatment oil concentration, placed on one randomized side of the tank, and filled with 7.0 psu water mixed using Instant Ocean™ salt and dechlorinated tap water. A single F. grandis from one of the randomly selected previous exposures was added to the tank, allowed to acclimate for 5 minutes, and then an observation of which side of the tank the fish occupied was made every 30 seconds over a 10-minute period. Tanks, fish, and side of the tank containing oil were randomized. Survivorship in exposures limited replication in some cases. Most comparisons were replicated n=8, except for medium oil previous exposure in the medium oil preference test (n=4) and no trials were conducted for high exposure fish for the medium and high choice tests. Methods used during this study are based on methods found in Martin, C. (2017).

Provenance and Historical References:

Martin, C. (2017). Avoidance of oil contaminated sediments by estuarine fishes. Marine Ecology Progress Series, AdvanceView, 1–10. doi:10.3354/meps12084

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