Submersible acoustic transmitter, low frequency transducer, loudspeaker, sounder, developed to attract fish
Sensor: Acoustic transmitter
Frequency: Programmable from 100 Hz to 2 KHz
(outside ranges available upon request)
Transmitting range: ~1.5 km in radius
Beam transmitted pattern: Omnidirectional
Transmission interval: User programmable
Control chassis material: Stainless steel and aluminium
FishCall is a unique submersible acoustic transmitter (sounder) developed for transmitting low frequency sound underwater to attract fish to the sound source, or can be used to scare them off. It contains a transducer (underwater loudspeaker). The user can define transmitting range to be from 100 Hz to 2000 Hz. It is also possible to define intervals of sound transmissions. Transducers can be set to transmit signals at different times or simultaneously if needed.
In order to use the FishCall the following items are needed:
- Transducers (loudspeakers)
- Amp and preamp
- Computer and USB hub
- Star-Oddi software
- Underwater cables
Additionally the user has to have facility on shore with electricity access where the PC, amp + preamp are housed. The cables are connected from the facility to the subsea transducers. All commands to the underwater speakers are remotely controlled through the PC.
Examples of Application
The main objective with the FishCall is to offer a new and environmentally friendly fishing technique where sound signal is used to attract fish to the sound source platform. In a study using FishCall it was shown that it's possible to use the acoustic transmitter to transmit sound signals at low frequency to caged fish, train them to respond to the sound and lead them to the sound source where they are rewarded with food. It was also shown that fish quickly learn from trained fish and follow the leader to the sound source.
Although it has only been tested in a sea cage, it should also be possible for a trained fish to lead a school of wild fish into a trap and thereby facilitating capture or ranching of wild fish in open fjords. Read more about the scientific study here.
Nature magazine published an aricle in the April 2011 issue about the FishCall. Read the article in Nature.
The FishCall can also be set at certain frequency with the aims of keeping herds of fish away from certain area. With the unique technology of a powerful loudspeaker low frequency sounder it opens up doors for various applications that marine biologists may have.
|Size (diameter x length)||20 cm x 14 cm x 22 cm|
|Housing material||Stainless steel and aluminium (non-corrosive)|
|Weight (in air/in water)||15 kg|
|Output power||250Hz 150 dB/1 µ Pa/1 m |
400Hz 154 dB/1 µ Pa/1 m
700Hz 156 dB/1 µ Pa/1 m
1KHz 156 dB/1 µ Pa/1 m
Higher output can be obtained with external power source.
|Transmitting range||~ 1.5 km in radius with reference to 80 dB (ref. 1 uPa@1 meter at 250 Hz) signal strength|
|Input voltage||48 volt|
|Beam transmitted pattern||Omnidirectional|
|Frequency||Programmable from 100 Hz to 2 KHz|
|Transmission interval||User programmable|
|Operational depth||Up to 50 meters (higer ranges available upon request)|