David Attenborough Wild Isles TV programme to highlight plight of Scotland’s wild salmon

It will highlight the plight of the species, which has been disappearing at a frightening rate. Scotland’s total population of wild Atlantic salmon has dropped to a quarter of the 1980 level in the past 30 years.

Experts have warned it could become endangered in the next few years if declines continue at the current pace and may vanish entirely within the next two decades.

Many factors have been blamed, including attacks from predators, aquaculture, over-fishing, pollution, man-made barriers in rivers, disease and the effects of climate change. The declines are bad news for salmon, but also rings warning bells for other wildlife and habitats.

According to conservationists, the unusual ability of Atlantic salmon to dwell in both rivers and oceans and the long distances travelled means the species acts an important indicator for the overall health or otherwise of freshwater and marine environments across many regions.

So – perhaps no surprise – we can conclude that neither our rivers nor our seas are in great shape.

The fourth episode of Wild Isles will be aired this Sunday, not long after the Scottish Government was rapped over long-term failures to safeguard wild salmon from the negative impacts of fish farming, including pollution, pests and diseases and interbreeding with escaped domestic fish.

A new report by the inter-governmental North Atlantic Salmon Conservation Organisation, of which Scotland is a member, concludes “few effective measures have been translated into practical action to manage the adverse effects of salmon farms on wild Atlantic salmon stocks”.

A Scottish Government spokesperson said the issue of declining native salmon stocks is being taken “very seriously” and work is ongoing at home and abroad “to safeguard this iconic species”. But it’s clear more needs to be done – and fast – if we don’t want to lose our ‘king of fish’ for ever.