Sea trials are scheduled to be held off the Portuguese coast to test a new acoustic deterrent device which aims to keep orcas away from boats

A new acoustic deterrent device is to be tested in the waters off Portugal to see if it will deter orcas from interacting with boats.

For years, the mainly juvenile cetaceans have been ‘playing’ with boats along the Iberian Peninsula, touching, pushing and pivoting on vessels.

In some cases this disruptive behaviour by the orcas has resulted in damage to the stern, mainly on the rudder; three boats have also been sunk as a result of the damage.

Portuguese and Spanish scientists at Grupo Trabajo Orca Atlantica (GTOA) have been studying the behaviour of the orcas since 2020, and are working in collaboration with Instituto da Conservação da Natureza e das Florestas (ICNF), the Portuguese government department responsible for Nature Conservation and Forests, and the Cruising Association, which is gathering data on orca interactions.

orcas under boat

If the trial is successful, the orca acoustic deterrent device could be available for the 2024 sailing season. Credit: Zoe Barlow

The new acoustic deterrent device has been created by the Edinburgh-based GenusWave.

The Targeted Acoustic Startle Technology – known as TAST – is designed to trigger the instinctive startle reflex most animals have when they hear a particular sound.

This reflex, governed by the autonomic nervous system, induces an involuntary flight response, compelling targeted animals to flee the immediate area.

TAST was originally developed to deter seals from fishing nets, and has been modified to work on sea lions and orca.

In November 2021 and 2022, trials took place on fishing grounds in Kvænangen in north Norway to ascertain how effective TAST was in deterring orca from fishing boats.

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Scientists counted orca before, during, and after the fishing boat emitted a sound. Each phase lasted five minutes.

Satellite marked the animals to measure their response to the startling sounds, and the orca quickly returned to the site when the noise subsided.

The findings determined that the GenusWave signal resulted in:

  • An 85% reduction in orca sightings on the fishing grounds during playback of the audio signals compared to before playback.
  • A deterrent range that was predominately 0-50m from the sound source
  • No harm to orca from the sound
  • No lasting exclusion from the area once the sound was turned off

According to ICNF and GenusWave, if the orcas are still in the vicinity off the Portuguese coast it is anticipated sea trials will commence in mid-October.

An orca interacting with a yacht. Credit: Grupo de trabajo Orca Atlántica (GTOA)

An orca interacting with a yacht. Credit: Grupo de trabajo Orca Atlántica (GTOA)

If the trials proceed, skippers will be asked to contact the ICNF/GenusWave to alert them if orcas are spotted. Details on how to contact the ICNF/GenusWave will be released at

According to GenusWave, if the trials are successful, it is anticipated that acoustic deterrent devices for yachts will be made available for the 2024 season.

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