Porpoise - PAL (pat.)

The Porpoise-PAL imitates alerting signals of porpoises at their ultrasonic communication frequency of 133 kHz. Optimised for the use in fisheries. A bycatch reduction of around 80 % in the Western Baltic Sea (Chladek et al. 2020; Fish Res) was Independently proven by the Thünen-Institute of Baltic Sea Fisheries.

Porpoise-PAL ultrasonic clicks are not audible by fish, most other animal species and seals: attraction to the nets or depredation on fish were not observed.
Key features Porpoise - PAL:
  • Waveform: narrow band porpoise clicktrain
  • Frequency:  133 kHz porpoise clicks
  • Signal Duration: 1 s
  • Signals: 1-3 random
  • Repeat Interval: 8 – 24 s randomized
  • Sound level: 145 dB re 1µPA @ 1 m peak
  • Spacing: 180 - 200 m on float line
The Porpoise-PAL has a very robust, black, UV-protected housing. To increase safety on board, it is light, buoyant and has an internal shock-absorber. Designed, manufactured and tested in Germany. Two year warranty against manufacturing defects.
Key features:
  • Proven bycatch reduction
  • Independently tested
  • Spindle shaped
  • Easy to deploy
  • Audible functionality check
  • Very durable, UV protected
  • Replaceable battery
  • Rated to 320 m depth 
Technical specifications:
  • Data recording (optional): total time, deployment time, temperature, signal generation
  • 250 g light, buoyant in water, helps pull nets open
  • 185 mm long, 60 mm diameter 
  • Dual attachment through 6 mm and 11 mm holes at each end
  • Approximate battery life (temperature dependent):
    • 4 years shelf life
    • up to 2 years typical use

Frequently asked questions

If you have any questions regarding PAL, its deployment and effect, please check FAQ here and feel free to contact us.
Proudly powered by Weebly