signal line

fishing

Also known as: herring telephone

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 13, 2026

Quick Summary

A signal line, also known as a "herring's telephone," was a traditional method used in fishing to locate prey in deep waters. This involved dropping a long wire from a boat, and the fisherman could feel vibrations caused by fish touching the line. While this method was effective for certain fish, modern industrial fisheries have largely moved towards more advanced techniques.1

Modern fish finding relies heavily on technology. Echo sounders and sonar systems use sound pulses to detect fish, providing information on their size, abundance, and movement. Position-fixing equipment like GPS helps fishermen return to productive spots or specific locations. These technologies are often integrated into a single display, offering skippers comprehensive data for efficient fishing operations.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

commercial fishing
Fish finding
Herring fishermen used signal lines to find their prey in deep waters. These were long wires dropped from a boat; the fisherman holding the line in his hand could feel the vibration caused by the fish touching the line, which was named the herring’s telephone. Other fish were…
Read More
Herring fishermen used signal lines to find their prey in deep waters. These were long wires dropped from a boat; the fisherman holding the line in his hand could feel the vibration caused by the fish touching the line, which was named the herring’s telephone. Other fish were…
Read More