Research Document 1997/72

Standardization of Otter Trawlers Participating in the Sentinel Fisheries in the Northern Gulf of St. Lawrence in 1996

By Alain Fréchet

Abstract

The mobile gear sentinel survey follows a stratified random survey protocol similar to what is used in regular DFO conducted surveys. In contrast to these latter surveys, the sentinel surveys are done with multiple vessels. Each boat has a specific area to sample. It is thus necessary to standardize the fishing gear, the wing spread in particular. We present here results of calibrations done with a restrictor cable.

The calibration done with the restrictor cable allowed to reduce the inter-vessel variability of 25% to 6% with no bias due to depth. In the future, all nine sentinel boats using otter trawl will use these restrictor cables. The calculation of abundance indices will use 16.5 meters (54 feet) as wing spread distance for all boats.

 Complete PDF document
(10 pages; 533K)

Accessibility Notice:

This document is available in PDF format. If the following document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.

Offer to produce in both official languages:

This report uses scientific and technical terms and is published in the official language of the working group or scientific expert that produced the document. If this document is not accessible to you in the official language of your choice, please contact the Secretariat.

Date modified: