Tagged fish provide information to scientists that will aid the research and conservation of fish stocks.
The North-East Atlantic Fisheries Commission, of which Ireland is a member, has in recent years expressed serious concern regarding the levels of exploitation of salmon fishing grounds off the coasts of Greenland, the Faroe Islands and Norway.
The commission believes that unregulated fishing could reduce Atlantic salmon stocks to unsustainable levels.
A series of measures designed to conserve fisheries came into effect on 1 January 1971 and are being observed by Belgium, France, Federal Republic of Germany, Iceland, Ireland, Netherlands, Norway, Poland, Portugal, Spain, Sweden, the Soviet Union and the United Kingdom.
These include prohibiting fishing for salmon in two geographical locations of concern, a ban on salmon fishing in those areas for specific periods, and restrictions on the size of fish caught.
Dr Arthur Went explains how the tagging of salmon in Irish waters since the turn of the century has provided scientists with sufficient data to establish that
Fish from Ireland are going over a very large range.
An RTÉ News report broadcast on 7 January 1971. The reporter is Barry Linnane.
