Campaigners are calling for an urgent investigation into Scottish salmon farms to prevent a "summer surge of deaths".

They delivered a petition with 40,000-signatures to the Scottish Government calling for emergency inspections of all commercial salmon farming operations.

The petition, by consumer watchdog SumOfUs, cites evidence of serious welfare abuses at some of the farms.

Campaigners are now demanding urgent action with disease among salmon populations increasing as sea temperatures rise during summer months.

Secret footage captured last month showing caged salmon near Loch Shieldaig, forced Marine Scotland to carry out an emergency inspection.

The footage was filmed by salmon welfare campaigner Don Staniford.

Anna Liberadzki, Campaigner at SumOfUs, said: "For years, we've known that Scottish salmon cultivation is as horrific as battery farming. Recent footage of the terrible conditions on salmon farms shows that the problem is only getting worse.

"As long as the megacorporations who own Scotland's salmon farms can get away with it, they will allow the fish to suffer, while raking in huge profits for a so-called 'sustainable' product.

"Marine Scotland must step in. The alternative is a summer surge of salmon deaths and disease,"

Don Staniford, director of Scottish Salmon Watch, said: "Salmon farming is a welfare nightmare. We know from the Scottish government's own surveillance that Scotland's salmon farms are riddled with infectious diseases, pathogens and viruses. Unannounced inspections of salmon farms are urgently needed to prevent further mass mortalities and welfare abuse."

A protester told STV News: "Scottish salmon is an icon to Scotland, but that's not the truth anymore. This is a battery, factory, caged product. We're bringing shame globally to Scotland.

"Campaigners are calling on the Scottish Government and Marine Scotland to conduct immediate inspections of salmon farms. We think that salmon farms are slipping through the net.

"The Scottish Government are not doing anything. They have only conducted one or two unannounced inspections in the last year. We don't think that's good enough. So if the Government won't do it, I think public citizens need to step in and do some filming in and around salmon farms themselves.

"There's a huge disease crisis in salmon farming in Scotland."

In October 2018 Cabinet Secretary for the Rural Economy, Fergus Ewing, revealed there had been only two unannounced site inspections of fish farms "in the last year".

Hamish Macdonell, director of strategic engagement for the Scottish Salmon Producers Organisation, said: "The Scottish salmon farming sector operates to a level of transparency that is unparalleled in other food production sectors.

"The sector is supportive of legitimate independent scrutiny, it is what helps businesses and the sector improve and grow.

"The Scottish government's fish health inspectorate has powers to make unannounced visits at any salmon farm. In addition, farms undergo audits and inspections from retailers, UK and international certification schemes, regulators and other stakeholders so there is seldom a week goes by that their operations are not scrutinised."

The Fish Health Inspectorate has a statutory requirement to carry out "unannounced site inspections".

A flotilla protest against welfare abuses on Scottish salmon farms, organised by Scottish Salmon Watch, will take place on September 1 at various locations on the west coast of Scotland.