URGENT action is to be taken to replenish salmon stocks on a Highland river after it emerged the fish population is close to vanishing.

The River Garry in Inverness-shire has been stripped of its stock over the past 50 years, with just 60 upstream Atlantic salmon counted last spring.

This compares with some 800 fish recorded in the same area in the late 1950s.

The total number of fish running into the River Ness system has also fallen dramatically, with catches down for the sixth year in a row.

The arrival of large numbers of goosander and meganser ducks and predatory fish species, including pike, are thought to be behind the changes.

The Ness District Salmon Fishery Board said the population changes were of significant concern given that salmon fishing has long been a major economic benefit to the area, supporting hundreds of jobs and generating large sums in tourism income.

It described research into the state of the river, carried out by Dr Eric Verspoor of the Rivers and Lochs Institute of the University of the Highlands and Islands, as disturbing.

Michael Martin, chief executive of the fishery board, said: "There are genuine threats emerging to salmon stocks in the area and we're keen to make progress in addressing them.

"The decline of the once famous early-running River Garry spring salmon has been felt along the entire length of our system. The stocks of these fantastic fish are now at a perilously low level and addressing this is a top priority."

He said the board hoped to work with Scottish & Southern Energy, which operates the Invergarry Dam and has responsibilities to the surrounding environment, to bring salmon numbers back up in the area.

Migratory ducks pose a significant risk to the salmon stocks, with around 90 birds, which eat salmon fry and parr, appearing during the breeding season. Farmed salmon are also known to have diluted the genetics of the wild species, leaving them less able to survive the natural conditions. Nets at the mouth of the Garry are also believed to have strained populations.

Work undertaken this year on replenishing stocks would not have an impact until 2018.

Mr Verspoor said scoping the necessary biological and engineering work to improve the habitats was required. He added: "Given this long timeframe, there is a need to move forward positively as quickly as possible with a carefully crafted programme of habitat and stock enhancement."

Andrew Graham-Stewart, director of the Salmon and Trout Assocation, said he was aware of issues on the River Ness but was unable to comment specifically on the research. He added: "On the east coast and the north coast, after two to three decades of decline, the stocks seem to be fairly stable.

"In the west Highlands and islands, where salmon farming is prevalent, there has been a significant decline in the wild salmon population."

A spokesman for SSE said: "We have long-standing and regular contact with the Ness District Salmon Fisheries Board and are supportive of moves to increase the numbers of salmon in the upper Garry. We will continue to work with the board to investigate options and identify what role SSE can play in this process."