Post-season changes have been announced for three of Scotland's salmon rivers – and reveal something of a north-south divide in salmon stocks.

The proprietors and management of the Thurso have opted not to operate the river’s hatchery this winter …. as they believe that stocking next spring will be superfluous. This move is in response to the large number of salmon currently in the river – and now spawning. 2011 has seen an excellent run of multi sea-winter salmon.

Eddie McCarthy, Thurso River Superintendent, said: “We have decided that, because there are so many fish around, we will leave it completely to nature this year and mothball the hatchery”.

Typically, between 150,000 and 300,000 fry of hatchery origin are planted out annually on the Thurso.

The Thurso’s decision follows the Spey Fishery Board’s recent announcement that, following genetic analysis of the efficacy of its hatchery operations and subsequently a thorough review of its stocking policy, it is reducing significantly its hatchery output for 2012 to between 250,000 and 300,000 eggs (this compares with 1.1 million in 2011 and 2.2 million five years ago), allied with a more targeted approach to stocking that can be effectively monitored

Meanwhile, from opening day until June 1, anglers will have to adhere to a strict new catch-and-release policy on Stirling Council's beats on the rivers Forth and Teith. Following a recommendation by the Forth District Salmon Fisheries Board, the Council has introduced this in an effort to halt the decline of spring salmon and sea trout.

The council has called on private beats on the river to do the same. Fisheries Officer, David Jones, said: "We are working closely with the Forth District Salmon Fishery Board and the Forth Fisheries Trust in an effort to improve the spring run. Mandatory catch-and-release will play a significant part towards achieving this.”

Anglers must also use barbless or debarbed hooks once they have used their allocated tags.