The report examined the effectiveness over a two year period of two devices in reducing seabird interactions with trawl warp wires:
- warp deflectors (pinkies) – a plastic “pinkie” buoy that is attached to the trawl warp by a clip and connected back to the vessel on a rope
- warp scarers – a rope interlaced with semi-stiff streamers that is clipped onto the trawl warp.
Nine trawl boats participated in the trial in the Great Australian Bight and Commonwealth Trawl Sectors of the Southern and Eastern Scalefish and Shark Fishery. A total of 124 trawl shots were observed to assess how well the mitigation devices worked. The trial was conducted in areas of high seabird concentration to ensure there was robust information on the effectiveness of each mitigation device.
Results from the trial showed that pinkies were most effective at reducing seabird interactions with warp wires while warp scarers had only limited success.
The trial also highlighted when seabirds were not at risk. No seabirds were observed interacting with the net itself because the net sinks rapidly and does not spend much time on the surface. Importantly, only two heavy seabird interactions occurred at night, suggesting that trawling outside of daylight hours reduces the likelihood of seabird interactions compared to trawling during the day.
AFMA have advised that they will use information from the trial to improve existing practices including:
- increasing pinkie size from 400mm to 600mm diameter (the size used in the trial)
- removing the requirement to use physical mitigation at night
- removing the warp scarer as an approved mitigation device
The Association will continue to develop and then trial bafflers and sprayers under the same methodology using funding from the Australian Government. It is hoped these new mitigations might further decrease interactions.