AEI prepress abstract  -  DOI:

Soundscapes in aquaculture systems

Craig Radford, Matthew Slater*


ABSTRACT: Sound in aquaculture production systems remains poorly understood in terms of both biological effects and engineering possibilities. Open systems such as sea cages and traditional ponds are increasingly complemented by recirculating aquaculture systems (RAS) which present important soundscapes for early life stages and for high value commercial species. The current study compares recordings of soundscapes from commercial sea cages, earthen ponds, and concrete and high-density polyethylene RAS holding systems. Calibrated measurements of each acoustic habitat reveal the range and intensity of sound in each system type. Spectra of each type of holding system are overlaid with hearing ranges and sensitivity levels of 4 commonly aquacultured fish, common carp Cyprinus carpio, European perch Perca fluviatilis, Red sea bream Pagrus major, Atlantic salmon Salmo salar, and 1 crustacean, common prawn Palaemon serratus. The majority of ambient noise recorded in RAS Systems and sea cages falls within the 100–500 Hz range at or near fish hearing thresholds. While RAS Systems are a markedly louder environment for species otherwise held in earthen ponds, the sea cage environment clearly represents the most variable and loudest aquaculture holding system, reaching noise levels capable of eliciting a measurable physiological response in many species and revealing a likely source of chronic stress. The long-term stress response of culture animals and performance cost of inappropriate soundscapes remains undetermined. A precautionary approach and optimized system engineering is recommended to reduce the sound impact on culture animals to optimize growth performance.