Total catch-and-release policies for salmon on all Scottish rivers for the remainder of the spring run is the urgent plea from the Association of Salmon Fishery Boards (ASFB).

And the 100% return policy should cover all sea trout throughout the 2009 season, they urge.

The call for maximum restraint for the next two months follows an alarming drop in 2009 catches during the first few weeks of the new season.

Hugh Campbell Adamson, ASFB chairman issued the call on a “precautionary basis” noting that the “scarcity of spring salmon so far this season appears to be a cause for serious concern.”

Returns on the River Tweed, one of the most prolific Atlantic salmon runs, are understood to be down by 50% on 2008 levels.

Nick Yonge, clerk to the River Tweed Commission, said: “Something has clearly happened at sea to upset this very fragile component of Scottish salmon stock and the Commission has already written to all beats urging themt to spare as many spring caught fish as possible.”

Yonge points out that two-thirds of Tweed spring catches have been released in recent years.  “This has given it a run which is just large enough to provide spawning fish to sustain the spring stock.”

Unfortunately for the ASFB, the plea comes just five weeks after the association published its first annual review in which it said it was clear that rod catch levels were stabilising.

Andrew Wallace, the ASFB’s managing director says the 2009 results are “most disappointing”, adding:

“It suggests that the recovery is fragile and hence the need for special measures to be adopted immediately. There can be little doubt that marine survival of this year’s spring salmon has been particularly poor.”

The Scottish Government’s Fisheries Research Services (FRS) long-term analysis of marine survival levels indicates that in the 1960s between 25-30% of juvenile smolts would survive at sea to return to spawn.  Today the level is around 10%.

The ASFB says the decline is “almost certainly related to climate change and its impact on the abundance and availability of the species on which salmon feed at sea.”

The association called for coastal netsmen not to begin fishing until the end of June.