Survival of saithe (Pollachius virens L.) escaping through trawl meshes

Abstract

A pilot study to estimate the survival of saithe escaping from a cod-end with 145 mm diamond meshes was done in April-May 1992 north of the Faroes. Escaped fish were collected in fine meshed net cages (2x2x5m aluminium frame) mounted aft on a cod-end cover. After one hour trawling below 150m depth the cages were released by means of an acoustic release system and slowly hauled up to 40m below sea surface for UTV observations ( 6-7 days). The net cages were drifting freely with the current in the area north of the Faroes and located by means of radio tracked buoys. Preliminary results indicate that saithe can withstand almost the same sorting as cod with low mortality. However, more experimental work is needed to draw more firm conclusions on survival rates of saithe escaping from a cod-end.