The decline in salmon numbers on Scotland's rivers has been a concern for many years, leading to strict conservation measures. The unusually high levels come after a poor year for spring salmon, which play a key role in the salmon stocks for the rest of the year. The new figures came from research being carried out by the Association of Salmon Fishery Boards (ASFB) and the Rivers and Fisheries Trusts of Scotland (RAFTS). A spokesman said: "We need to be cautious about what catches are telling us about fish stocks. "Salmon are still nowhere near as abundant as they were 50 years ago." According to research published by the Scottish government in 2010, there was a 67% release rate for fish caught by rod in Scotland. That figure stands at 82% for spring salmon.