Location: Cool and Cold Water Aquaculture ResearchTitle: The effects of aquaculture production noise on the growth, condition factor, feed conversion, and survival of rainbow trout, Oncorhynchus mykiss) Author
Submitted to: Aquaculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/25/2008
Publication Date: 3/1/2009
Citation: Davidson, J., Bebak, J.A., Mazik, P. 2009. The effects of aquaculture production noise on the growth, condition factor, feed conversion, and survival of rainbow trout, Oncorhynchus mykiss. Aquaculture. 288(3-4):337-343. Interpretive Summary: We investigated the effects of aquaculture production noise on rainbow trout growth and physiology, concluding that intensive aquaculture production noise, particularly sound levels associated with recirculating systems, do not inhibit long term rainbow trout growth and survival, and thus corroborating previous finding, Wysocki et al. (2007b). Although long term rainbow trout growth was not impacted by the sound levels tested, rainbow trout did appear to exhibit a stress response to the 149 dB sound level when the treatment was initiated, as indicated by significant lower growth rates of individual fish over the first month. However, rainbow trout seemed to acclimate to the continuous sound stimulus over the next four months and grew at the same rate as the control sound treatment, i.e. 117 dB. Overall the impact of sound levels common to recirculating aquaculture systems seems to be very subtle, however, management of noise associated with these culture systems should still be considered.
Technical Abstract: Intensive aquaculture systems, particularly recirculating systems, utilize equipment such as aerators, air and water pumps, blowers, and filtration systems that inadvertently increase noise levels in fish culture tanks. Sound levels and frequencies measured within intensive aquaculture systems are within the range of fish hearing, but species-specific effects of aquaculture production noise are not well defined. Field and laboratory studies have shown that fish behavior and physiology can be negatively impacted by intense sound. Therefore, chronic exposure to aquaculture production noise could cause increased stress, reduced growth rates and feed conversion efficiency, and decreased survival. The objective of this study was to provide an in-depth evaluation of the long term effects of aquaculture production noise on the growth, condition factor, feed conversion efficiency, and survival of cultured rainbow trout, Oncorhynchus mykiss. Rainbow trout were cultured in replicated tanks using two sound treatments: 117 dB re 1 microPascal RMS which represented sound levels lower than those recorded in an intensive recycle system and 149 dB re 1 microPascal RMS, representing sound levels near the upper limits known to occur in recycle systems. To begin the study mean fish weights in the 117 and 149 dB tanks were 40 and 39 g, respectively. After five months of exposure no significant differences were identified between treatments for mean weight, length, specific growth rates, condition factor, feed conversion, or survival (n=4). Mean final weights for the 117 and 149 dB treatments were 641 +/- 3 and 631 +/- 10 g, respectively. Overall specific growth rates were equal, i.e. 1.84 +/-0 0.00 and 1.84 +/-0.01%/day. Analysis of growth rates of individually tagged rainbow trout indicated that fish from the 149 dB tanks grew slower during the first month of noise exposure (p<0.05); however, fish acclimated to the noise thereafter. This study further suggests that rainbow trout growth and survival are unlikely to be affected over the long term by noise levels common to intensive aquaculture systems.