The following are prerequisites for effective acoustic fish herding:
- The fish species must be highly sensitive to sound - cyprinid (carp family) or clupeid (herrings, shads etc.), for example. Less sensitive species can be herded but the range of effect of the deterrents will be less and it may not be cost effective to operate the required number of deterrent devices.
- There must be ‘safe’ areas of water into which the fish can be driven.
- The water must be deep enough to allow the sound to propagate (typically > 2 m).
- Background noise should be low, i.e. not busy ports and harbours.
In fish herding applications the fish deterrent system is operated from a mobile platform such as a boat or barge. This differs from static deterrent systems often used to drive fish from a confined locality in blasting operations.
To specify an appropriate system we will need information on the species of fish to be herded, the distance/area to be covered and the water depths involved. For marine areas, water depths can be obtained from marine charts but when required FGS can also offer a rapid bathymetric survey option for river reaches.
Fish herding systems are available for short-term hire, long-term lease or purchase.