Abstract:

This dataset explored the effects of oil exposure on thermal tolerance using the aerobic scope. The study defines the aerobic scope temperature curve in animals acclimated (14 days), or acutely exposed to 25, 30 and 35 degrees Celsius. This study design will be repeated in animals exposed to oil to explore whether oil exacerbates thermally induced aerobic collapse.

Suggested Citation:

Ackerly, Kerri, Andrew Esbaugh. 2020. Effects of oil exposure and thermal performance in red drum (Sciaenops ocellatus). Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-tsgf-g097

Purpose:

Investigate the impacts of oil exposure and temperature on red drum.

Data Parameters and Units:

The first tab in this file (Fish & Trial Information) shows the fish identification, mass (grams), total length (cm), and standard length (cm). The mass is the overall wet mass of the fish. Total length is the length of the fish from the tip of the snout to the tip of the tail fin. Standard length is the length of the fish from the tip of the snout to the base of the caudal fin. The tabs following are the raw data for each individual mentioned in the Fish & Trial Information tab. The tab is labelled with the appropriate fish’s ID. The tab contains information regarding the date the trial took place, whether the fish was oil or control, the date the respirometry trials (MMR and SMR) started, the recovery level in % air sat the fish was placed in after MMR, and the chamber # the fish was placed in. The file also contains the loop, the details of the loop (in seconds), the MO2 of that chamber, the R2 of the chamber, the amount of background there is calculated for each loop, the MO2 minus the background, the phase of the trail, and the average DO in % air sat for each loop. A loop is a single respirometry measure period. The next column is the details of the loop. It contains a certain number of seconds the chamber the fish is to flush with seawater (flush period), the number of seconds the chamber recirculates the water without measuring oxygen consumption by the fish (wait period), and the number of seconds the chamber recirculates water and measures oxygen consumption of the fish. Loop times vary with phase. Background loop times have an extended measure time. Pcrit measures have only measure phases. Pcrit phase is the end of the SMR trial where water only recirculates and measures. The MO2 of the chamber is the metabolic rate of the fish, which is calculated by how much oxygen they consume during the measure phase. The R2 is the statistical measure of how well your data fit a line (a decline in the amount of oxygen in the chamber). The R2 must be above 0.95 to be included in the dataset. The background of the chamber is a measure of the amount of bacterial respiration that occurs in the chamber when the fish is not present. These phases have longer measure periods. The background is then calculated incrementally increasing with each loop. The background – MO2 column is the MO2 value for that loop minus the calculated background for that loop. The phase of the trial includes background start (the measure of bacterial respiration before the fish were in the chambers), MMR (maximum metabolic rate, the first 5 measures after exercise that the fish was in the chamber), EPOC (excess post-exercise oxygen consumption, the recovery time following exercise while the fish returns to baseline), SMR (standard metabolic rate, the 24h measure period of SMR), PCRIT (critical oxygen threshold, the period following SMR when the chamber was closed to new water), and background end (the measure of bacterial respiration after the fish were in the chambers). The averaged DO (dissolved oxygen) is the amount of oxygen (as % air sat) measured across the entire loop. Please note that the individuals in the control group had no oil exposure, individuals in the oil group were all exposed to oil, individuals exposed to oil were exposed to an average of 44.5 μgL-1 ΣPAH50 (20% HEWAF), and NA means data are not available.

Methods:

Dataset contains data on farm-raised red drum exposed to either a 20% HEWAF of OFS oil or clean seawater. Juvenile red drum were kept in holding tanks and acclimated for a minimum of 2 weeks before being used in this study. Individuals were acclimated to one of four temperatures for a period of three weeks. 32 fish were acclimated to each temperature. All fish were then placed into 5 L of 20% HEWAF oil exposure for 24 h. After exposure, control and oil exposures were placed into an experimental respirometry chamber at their acclimation temperature following maximum exercise challenges. Individuals had their aerobic scope and hypoxia tolerance measured. The oil used in this study was naturally weathered oil collected from an oil slick in the Gulf of Mexico on 19 July 2010 from a barge called the Juniper (A0087K). This oil was delivered to the University of Texas at Austin Marine Science Institute in Port Aransas, Texas under the appropriate chain of custody and was maintained in the lab at 4°C. Oil preparation for exposures was prepared using the standard protocols for high energy water accommodated fractions (HEWAF) as per Johansen & Esbaugh., 2017. The oil loading rate was 1 g per 1 l of filtered seawater (22°C) with a salinity of 25±2 ppt. The oil and filtered seawater were loaded into an industrial blender (Waring Commercial CB15T, Connecticut, USA) and blended on low for 30 s. The mixture was carefully transferred to a Teflon separation funnel and allowed to settle for 1 h before the lower 85% of the oil-water mixture was drained, covered completely in aluminum foil, and immediately placed at 4°C to prevent weathering until use. The remaining 15% of the HEWAF solution was discarded. All oil-seawater mixtures were used within 15 h of preparation. Each mixture was mixed on low (400 rotations per minute) for 10 min using a stir bar on a stir plate while being brought to the experimental (i.e. applicable acclimation) temperature before use.

Instruments:

Loligo systems, Autoresp

Error Analysis:

All endpoints were analyzed with either Two way ANOVAs or T-tests

Provenance and Historical References:

Johansen, J. L., & Esbaugh, A. J. (2017). Sustained impairment of respiratory function and swim performance following acute oil exposure in a coastal marine fish. Aquatic Toxicology, 187, 82–89. doi:10.1016/j.aquatox.2017.04.002

Individual Files: