Author
WYSOCKI, LIDIA - UNIV. OF MARYLAND | |
DAVIDSON, JOHN - FRESHWATER INSTITUTE | |
SMITH, MICHAEL - UNIV. OF MARYLAND | |
FRANKEL, ADAM - MARINE ACOUSTICS, INC. | |
ELLISON, WILLIAM - MARINE ACOUSTICS, INC. | |
MAZIK, PATRICIA - WEST VIRGINIA UNIV. | |
POPPER, ARTHUR - UNIV. OF MARYLAND | |
Bebak, Julie |
Submitted to: Aquaculture
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/25/2007 Publication Date: 11/26/2007 Citation: Wysocki, L.E., Davidson, J., Smith, M.E., Frankel, A., Ellison, W., Mazik, P.M., Popper, A.N., Bebak, J.A. 2007. The effects of aquaculture noise on hearing, growth and disease resistance of rainbow trout Oncorhynchus mykiss. Aquaculture. 272(1-4):689-697. Interpretive Summary: Intensive aquaculture production often utilizes equipment (e.g., aerators, air and water pumps, harvesters, blowers, filtration systems, and maintenance machinery) that increases noise levels in fish culture tanks. Consequently, long-term exposure to elevated noise levels could negatively impact cultured species. Possible effects include impairment of hearing ability, increased stress, and reduced growth rates. The objective of this study was to evaluate the long term effects of sound exposure on the hearing sensitivity, growth, and survival of cultured rainbow trout (Oncorhynchus mykiss). Rainbow trout were cultured for eight months in one of three sound treatments: 115, 130, or 150 dB re 1 µPa RMS. There were no significant differences in hearing ability that resulted from exposure to increased sound levels. Also, there were no differences between sound treatments for growth rates, mortality occurring throughout the study, mortality due to infection with Yersinia ruckeri, or blood chemistry values. This study indicated that rainbow trout hearing sensitivity, growth, survival, stress, and disease susceptibility were not negatively impacted by noise levels common to recirculating aquaculture systems. These findings should not be generalized to all cultured fish species, however, since many species, including catfish and cyprinids, have much better hearing sensitivity than rainbow trout and could be affected differently by noise. Technical Abstract: Intensive aquaculture production often utilizes equipment (e.g., aerators, air and water pumps, harvesters, blowers, filtration systems, and maintenance machinery) that increases noise levels in fish culture tanks. Consequently, chronic exposure to elevated noise levels in tanks could negatively impact cultured species. Possible effects include impairment of the auditory system, increased stress, and reduced growth rates. The objective of this study was to evaluate the long term effects of sound exposure on the hearing sensitivity, growth, and survival of cultured rainbow trout (Oncorhynchus mykiss). Two cohorts of rainbow trout were cultured for eight months in replicated tanks consisting of three sound treatments: 115, 130, and 150 dB re 1 µPa RMS. Auditory evoked potential recordings revealed no significant differences in hearing thresholds that resulted from exposure to increased ambient sound levels. Moreover, while there was no difference in hearing thresholds for fish within each cohort, there were significant differences in hearing thresholds between cohorts. No statistical differences were found between sound treatments for growth rates, mortality occurring throughout the study, and blood chemistry constituent concentration, for fish within each cohort. There was no significant difference in mortality between sound treatments when fish were exposed to Yersinia ruckeri, but there was significantly different mortality between cohorts. This study indicated that rainbow trout hearing sensitivity, growth, survival, stress, and disease susceptibility were not negatively impacted by noise levels common to recirculating aquaculture systems. These findings should not be generalized to all cultured fish species, however, since many species, including catfish and cyprinids, have much better hearing sensitivity than rainbow trout and could be affected differently by noise. |