The traditional start to the salmon fishing season is to be delayed by two weeks in parts of Perthshire because anglers have claimed it is too early.
The salmon fishing season on the Tay begins in mid-January
The head ghillie on the Newtyle beat of the River Tay said they must respond to climate change.
He said the traditional mid-January start was creating too much stress for the salmon whose spawning patterns seem to have been delayed by warmer winters.
Other fishing beats will begin the season as normal.
At Kenmore on the upper Tay the season has begun with a party in mid-January for almost a century and a half.
Tay District Salmon Fisheries Board sees no reason to change the practice, as breeding or spawning is usually over by then.
Fisheries manager David Summers said: "The Tay has some of the earliest runs of fish in Scotland and that's the reason why even since the 1860s it was felt appropriate to have a very early start in the Tay season."
However, about 20 miles downstream on the Newtyle beat at Birnam, while they still intend to throw a party, they have decided not to fish until 1 February.
The head ghillie for the area, John Monteith, said a heavy frost was needed to trigger the breeding season.
"This winter we had grass growing quite profusely into November and very few fish since then," he said.
"Hence the reason we've got a lot of fish in the river due to mild water temperatures, but they have not had the big nudge from mother nature yet to get about their business."
Richard Shelton, research director of the Atlantic Salmon Trust, said anglers should delay the season even longer.
"Although there are plenty fish late on in the season, early on in the season there are not and there isn't really an exploitable surplus," he said.
"The way round it economically and socially, and adopted in the Aberdeenshire Dee, is catch and release."
Fisheries manager Mr Summers said he did not believe there was any reason to postpone the season, although he did not criticise individual owners for doing so if they believed there were still spawning fish on any particular beat.