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 μPa RMS which represented sound levels lower than
those recorded in an intensive recycle system and 149 dB re 1 μPa 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 meanweight, 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±0.00 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 (pb0.05); 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.