The salmon fishing season on the River Tay is beginning with a warning that stringent conservation measures are needed.
Anglers are being urged to release the first salmon they catch each day
The Tay District Salmon Fisheries Board hopes new guidelines will double the number of fish released to continue their upstream migrations to spawn.
The board is recommending that until the end of May, the first salmon caught by every angler each day is released.
The anglers should then only keep one other fish that they catch per day.
From 1 June to the end of the season all female fish and half the male fish should be released.
All coloured fish should be let go throughout the year.
The use of worms will only be permitted from June to August.
John Milligan, chairman of the Tay District Salmon Fisheries Board, said: "All rivers are having to deal with the problem of increasing mortality of salmon at sea, which is caused by factors beyond our control relating to climate change.
"On the Dee over 90% of salmon caught by anglers are released and on the Spey over 70%.
"There is absolutely no reason why Tay anglers should not achieve similar figures so that many million more eggs can be laid in the river.
"We are optimistic that anglers will heed our appeals. We have no desire to seek mandatory powers to compel anglers to release fish but we will not hesitate to do so if the new recommendations are not closely adhered to."