top of page
Spinner Dolphins

STM Dolphin Deterrent Devices

Fishing activities are the most serious threat to dolphins, being the cause of the death of thousands of specimens in a year. On the other hand, dolphins are the cause of serious economic damage to fishermen, since the predatory activities of marine mammals cause loss of capture and damage to the nets.

DDDs are to be fixed to fishing equipment (nets, longlines, etc) and are activated when they come into contact with the water. They emit trains of ultrasonic signals at random frequencies, which prevent dolphins from becoming accustomed to signals. Even the intervals between a train of signals and the next one are random, but have different average durations, depending on the models suitable for the various types of fishing. The emission power is 165 dB (decibel), the highest existing, obtained thanks to a particularly sophisticated technology.

VOLTester High.jpg

Models & Downloads

Selection Guide


Refer to this guide to assist in selecting the correct model for your application

phpThumb_generated_thumbnail (1).png

 DDD 03H


Dolphin Deterrent Device

Usage: short gillnets, trawl nets, purse nets, longlines.
Average battery charge duration: 40 hours.
Horizontal distance between two devices: between 300 and 500 m.
Vertical distance between two devices (on the long lines): from 60 to 80 m.

 DDD 03U


Use: on single longlines.
Average battery life: 8 - 12 hours.
Vertical distance between two devices: from 40 to 60 m.

phpThumb_generated_thumbnail (1).png



Dolphin Deterrent Device

Usage: aquaculture, harbours, wind fields, marinas, with a minimum of 5 pieces.
Average battery charge duration: 300 hours.
Horizontal distance between two devices: from 200 to 400 m.



Dolphin Deterrent Device

Usage: long fixed- or drift-nets, minimal length 1 km, with a minimum of 5 pieces.
Average battery charge duration: 120 hours.
Horizontal distance between two devices: from 200 to 400 m.

phpThumb_generated_thumbnail (2).png

DiD 01


Dolphin interactive Deterrent

The DiD (Dolphin interactive Deterrent) is an equipment able to keep the dolphins away from fishing nets, thanks to an efficient technique of interaction with their echo-localization system (sonar).

It produces the ultrasounds only when it detects the presence of the dolphins in the area, by means of its “hearing” circuitry, that is activated by the “clicks” emitted by the mammals.

STM Products Fishing Technology

STM Products is an Italian company established in Verona that has been designing and producing industrial electronics since 1983, overseeing internally every strategic phase: research, design, software, hardware and mechanical development, both according to customers' specifications and standard, and the mass production.

The DDD, Dolphin Deterrent Device, are electronic devices resulting from a long project activity, in collaboration with prestigious research centers, such as the Institute of Marine and Environmental Research (IRMA) of the CNR of Mazara del Vallo and the Institute of Marine Research in Moscow. DDDs keep dolphins away from their greater danger, interacting with their eco-localization system (sonar), thus protecting the equipment and profitability of the fishing industry.

The DiD, Dolphin interactive Dissuasor, an evolution of the DDD models, produces ultrasound only when the presence of the mammals in the area is detected, through a special circuit, that "hears" the clicks emitted by them.

The devices comply with the Regulation of the European Union Council (EC) 812/2004 of 26 April 2004, Annex II.

The emission level of both devices, DDD and DiD, doesn’t produce any harm to mammals or fishes; these last are insensitive to the frequencies emitted.

The DDD / DiD pingers have proven their effectiveness in the seas of many areas of the world, since 2004, in tens of thousands of pieces.

bottom of page