The Effects of Seismic Technology on the Inner Ear of the Invasive Round Goby

Previous studies have shown that high-pressure sources such as seismic exploration technology can temporarily or permanently affect the auditory systems of numerous fish species. The majority of studies done on fish hearing aim to determine safe operating thresholds for different fishes to mitigate negative effects of these anthropogenic noise sources. In contrast, this study was designed to evaluate the effects of a hydraulic watergun on invasive round goby in Lake Michigan. With no internal barotrauma found in exposed round goby during a pilot study, the goal of the present study was to evaluate a potential sub-lethal endpoint by assessing damage to hearing endorgans. Round goby were exposed to 6 discharges from a 1966 cm³ seismic watergun at an average peak sound pressure level of 228 dB re1µPa. Fish were held for 3 days post exposure, euthanized and inner ear sensory hair cells and otoliths were preserved for analysis to examine the condition of round goby inner ears. Preliminary results indicate minimal damage, suggesting a higher peak pressure level or longer duration of discharges would be essential to inflicting significant damage.