What is a pinger?
It is an acoustic deterrent device fitted onto a fishing net. It works by emitting a regular sonic noise which can be heard by cetaceans (dolphins, porpoises and whales) and scares them away from nets, preventing accidental entanglement.
Aims of the pinger trial project
1. To test the practicalities of using pingers on smaller fishing vessels to establish their viability as a conservation tool.
2. To measure behavioural changes of different species due to the presence of pinger.
With the assistance of four volunteer fishermen the project has been able to collect a huge amount of information on both the practicalities and the effectiveness of using pingers on small inshore vessels.
Each vessel was equipped with two acoustic monitoring devices (CPOD’s) to record the cetacean echolocation activity around nets with and those without pingers. By using acoustic monitoring we have been able to study the effect of pingers in a short time frame in a fishery with a low bycatch rate.
Results
Results are extremely positive: with a 48% reduction in harbour porpoise activity around nets equipped with pingers. Unfortunately results for common and bottlenose dolphins were inconclusive due to the very low levels of activity recorded throughout the trial. Data strongly suggests that harbour porpoises would not habituate to the pinger signal and that the deterrent would remain effective.
Fishermen involved in the trial have been invaluable in testing pingers and their experience and feedback on practical issues has been extremely constructive. Very few practical issues associated with using the pingers were recorded, though some concerns were raised about the cost and life span of pingers.
Conclusions
- Functioning pingers would be an effective bycatch mitigation method
- Fishermen have tested practical aspects of using pingers, and have found them to present very few probelms to normal fishing activity.
- Data shows no habituation of harbour porpoises to the signal given off by the pinger.
- No clear statistical conclusion can be drawn regarding common and bottlenose dolphins due to very low activity levels recorded throughout the trial.
Our thanks goes out to all the fishermen involved in the trial, who have been invaluable to this project not only providing practical support but giving the project officer and insight into the inshore tangle net fishing industry.
A final report from the project will be available for download soon.
Funding for this project
This project has received funding support from the Esmée Fairbairn Foundation, the DEFRA Fisheries Challenge Fund and from Trust members, the public and local businesses who donated through our pinger appeal. The appeal for donations was a resounding success, exceeding the £15,000 target thanks to the generosity of donors. This reflected their interest and support for the project. All funding received has ensured the project will now go ahead.
The appeal for the pinger trial was supported by the following organisations:
- Frugi, a local children's organic clothing company. Frugi have supported the Trust through the 1% For The Planet scheme for the past three years and were proud to support the appeal for donations for this project.
- NABU, our wildlife friends in Germany.
