Ultra slow acoustic energy transport in dense fish aggregates.
Sci Rep
; 11(1): 17541, 2021 09 02.
Article
em En
| MEDLINE
| ID: mdl-34475477
ABSTRACT
A dramatic slowing down of acoustic wave transport in dense fish shoals is observed in open-sea fish cages. By employing a multi-beam ultrasonic antenna, we observe the coherent backscattering phenomenon. We extract key parameters of wave transport such as the transport mean free path and the energy transport velocity of diffusive waves from diffusion theory fits to the experimental data. The energy transport velocity is found to be about 10 times smaller than the speed of sound in water, a value that is exceptionally low compared with most observations in acoustics. By studying different models of the fish body, we explain the basic mechanism responsible for the observed very slow transport of ultrasonic waves in dense fish shoals. Our results show that, while the fish swim bladder plays an important role in wave scattering, other organs have to be considered to explain ultra-low energy transport velocities.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Som
/
Peixes
/
Ondas Ultrassônicas
Limite:
Animals
Idioma:
En
Revista:
Sci Rep
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
França