The catch statistics for salmon in 2014 confirmed that the rod catch was the worst since consistent records began in 1952.
A total of 45,175 salmon were caught by anglers, compared with 67,500 in 2013, while the five-year average was 85,000.
Of the rod catch, 37,139 (82 per cent) were released back into the water by anglers, but 8,036 (18 per cent) were killed.
The Salmon and Trout Association (S&TA) in Scotland has called for a “robust system” to ensure stocks are not exploited further, saying the numbers killed had been “dwarfed” by the 17,778 killed by nets.
It is backing moves to introduce a “kill licence”, which would mean anglers having to release fish back into the wild.
Chairman Hughie Campbell Adamson said: “Salmon runs are fickle and clearly conditions can impact on rod catches, but it would be irresponsible not to take heed of the significant downturn in the last two years which is mirrored across the North Atlantic.
“The figures underline why Scotland needs to have a robust system in place to ensure that any exploitation is limited to those stocks which have a discernible surplus. In this context, S&TA Scotland supports the principle of a kill licence system, as is currently being consulted on by Scottish Government.”
The S&TA has repeatedly called for tougher sanctions on netting operations throughout Scotland.
The Marine Conservation Society’s latest advice is that wild salmon taken in Scotland’s coastal nets are among the “least sustainable fish to eat and should be avoided”.
Government body Marine Scotland Science said: “Trends in total rod catch vary. Spring salmon catch [defined as multi-sea winter fish taken before 1 May] shows a general decline since records began.
“Although there is some indication that spring salmon catch has stabilised in recent years, it remains at a historically low level. Overall catch of salmon and grilse in later months showed a general increase up to 2010, after which it has fallen sharply.”
In order to regulate and thus limit salmon exploitation, the Scottish Government is consulting on the early introduction of a scheme under which the killing of salmon would be permitted only under licence.
Announcing the publication of the 2014 figures, Dr Aileen McLeod, minister for environment, climate change and land reform, accepted there had been a worrying decline in stocks in the last few years.
She said: “We are conscious of the concerns around the long- term health of fish stocks which is why we have brought forward statutory conservation measures over the last year and we are currently consulting on a proposed ban on the killing of wild salmon except under licence.
“We recognise that this has been a challenging year for rod fisheries, however it is good news that the proportion of fish returned to the water continues to rise.
“I would encourage all those interested in the future of our salmon stocks to share their views on how we might manage and conserve Scotland’s salmon stocks by responding to our consultation by 30 April.”
The S&TA was established in 1903 to address the damage done to rivers by pollution dating back of the Industrial Revolution.