Sampling Atlantic salmon in the NE Atlantic during summer: methods of capture and distribution of catches

Abstract

In July/ August 1991 the Institute of Marine Research (IMR, Norway) performed a pairtrawling (two boat trawl) experiment with a surface trawl to catch young herring in the northem Norwegian Sea. 34 postsmolts and two 1- sea-winter salmon were caught as bycatch. This was the first time that postsmolts were recorded in larger numbers during fishery in open sea in the North East Atlantic, although the area is believed to be the one of the main feeding areas for salmon during summer. A (one boat) pelagic research trawl has been developed by IMR for scientific surveys of the pelagic fish stocks. This trawl, an Åkra trawl, can be rigged both for mid water and surface trawling (0- ~ 25 m), and is currently in use on all pelagic research cruises. In 1993 a study was made to test whether the new trawl would catch salmon. This study proved successful, and consequently, Atlantic salmon was included in a large scale ecology study in the Norwegian Sea, the so called "Mare Cognitum Programme" (MCP). In 1995, the first year of salmon surveys in the MCP framework, in addition to the trawl surveys, otter- board salmon trolling and salmon drift line fishery with an experimental line with 200 hooks were developed and tested from the R/V "Johan Hjort". A total of 157 postsmolts and nine 1-sea-winter salmon have been caught in surface hauls since 1991. The fish have been caught in an area stretching from west of Scotland and the Hebrides up to 75°N and 18°E. The samplings have been performed from June to mid August.