Improvements in the use of 'pingers' which assisted their deployment in commercial fisheries

Between 2005 and 2007 we carried out trials to assess if acoustic devices called ‘pingers’ to be deployed on gillnets were suitable for use during commercial fishing activity.

Pingers, proven to greatly reduce porpoise by-catch by emitting a relatively low frequency signals that deter purposes from the area, were subsequently made a legal requirement on Irish commercial fishing vessels of 12m or over in the Celtic Sea.

Project aim: To assess the suitability of the device

The aim of the trial was to assess the suitability of the device, ease of handling of nets fitted with the device and their impact on fishing operations.

Our Methods: Trialing the pingers with industry during comercial fishing activity

In co-operation with industry we trialed four models of pingers (by different manufacturers) on gillnets on commercial fishing vessels in the Irish Sea.

 Key issues encountered during the trials included:

  • Major tangles of the devices in gear
  • Heavy damage to pingers due to collisions during fishing operations and poor general durability of pingers
  • Negative buoyancy of pingers - negatively affecting performance of fishing gear
  • Danger caused by lithium batteries being exposed to seawater in ruptured pingers

BIM addressed these issues by:

  • Developing a modified attachment system which primarily consisted of mounting individual pinger units between floats, in bait bag tubing, and attaching the customised device at the interface between sheets of netting known as the ‘joins’.
  • Reducing the impact of heavy collisions by the addition of net floats.
  • Preventing the tangling of pingers in the fishing gear as the modified system was larger than the meshe size.

We also conduced trials on the effectiveness of the pingers at various distribution densities.

pinger image

BIM's modified pinger attachment method was trialed on Irish commercial fishing vessels

Seeing the benefits: Economies in cost and handling of devices achieved

Our modified attachment method increased the durability of pingers.

Trials on the spacing of gillnet pingers demonstrated effective spacing of up to 500m instead of 200m which was subsequently legally permitted.

This  resulted in:

  • Reduced environmental pollution from lost or damaged pingers
  • Reduced noise pollution and associated potential porpoise habitat limitation
  • Improved economies in cost and handling of devices for fishermen

BIM also used data on bycatch of cetaceans from nets without pingers during the trials to provide an updated bycatch estimate for porpoises in the Celtic Sea in 2006. A major observed reduction in bycatch rates since 1993 was attributed to a major drop in gillnet fishing effort in the Celtic Sea over this period.

Full Report

Read the full report on the pinger trials (pdf 180Kb)  

Contact Us

To learn more about this project, contact:

Ronan Cosgrove
Direct: 091 564318

Daragh Browne
Direct: 091 564318