Two field studies with GenusWave's Targeted Acoustic Startle Technology system were conducted with MaREI (Marine Renewable Energy Ireland) at The Coastal and Marine Research Centre - University College Cork, Ireland and funded by Bόrd Iascaigh Mhara. These research studies were carried out under license from the National Parks and Wildlife Service.
Field Study 1
Four days of fishing trials were carried out on board the Dingle jigging vessel “Genesis”, skippered by Paul Hand.
On the first day, a number of grey seals were immediately visible. Once the system was deployed and signals commenced at depths of 5m and 7m, the visible seals moved out to between 200m and 300m away from the vessel and no fish were lost.
For the most part, the seals remained on the surface, looking at the vessel but they stayed outside an arc of at least 200m.
When the signal transmission was switched off some seals approached the vessel but gave a splash and rapidly removed themselves outside the effective range of the speakers once the transmission recommenced.
A similar pattern prevailed through the remaining days of the trial with no fish being taken by seals.
Field Study 2
Overall, the numbers of depredated fish (n=12) was extremely low, but predation was higher when the playback was switched off. No fish were depredated when the device was switched on. The data indicates that sound exposure significantly reduced the number of drifts that were predated.
The system was tested on board Tom Kennedy’s “Atlantic Fisher” (skippered by Johnny Connor) during a gill-netting trip off the Kerry and Clare coastline.
The startle device was only tested during the net hauls not while nets remained at depth.
Statistical models indicated a reduction in predation losses when the device was operating but this was only the case when fishing operations were conducted in shallow water (<160m). This may point towards deeper net deployments and hauls requiring speakers to also be deployed at depth for longer period of time, which requires further development work.