A Scottish fishery board says it has taken the "first ever footage" of a non-native species of salmon spawning in UK waters.
The pink, also known as humpback, salmon were filmed using Ness District Salmon Fishery Board's underwater cameras in the River Ness.
The fish are native to Pacific Ocean waters.
Pink salmon have recently been caught by anglers in the rivers Ness, Dee and Spey.
They were filmed on the River Ness near Inverness.
The fish are believed to be related to pink salmon introduced to rivers in Russia in the mid-1950s.
These fish have since gone on to be found in rivers in Scandinavian countries, including Norway.
Chris Conroy, the board's director, said: "This is undisputed proof that these non-native fish are attempting to spawn in our waters.
"We are forwarding this film to Marine Scotland to keep them aware of what is happening.
"It is, however, important to note that conditions in our rivers mean that the pink salmon eggs may not go on to successfully hatch - we will monitor the situation over the coming months."
Mr Conroy added: "We don't know why they are here or whether this is a one-off year for them or, ominously, a more regular feature.
"While the risks are unknown in terms of their interaction with Atlantic salmon and other Scottish fish, they are unlikely to have a positive impact."
Salmon and Trout Conservation UK and Prof Eric Verspoor, director of the Rivers and Lochs Institute at Inverness College UHI, have warned of the potential risk to native salmon.
Threats include competition for food.