Enormous shoals of sprat can be found in the North Sea

The smell, which has been described as intolerable by local residents, began when huge numbers of the dead fish floated to the surface.

So far, eight tonnes of sprat have already been removed from the surface of the water but there are still up to 10in of rotting fish below.

Yard owner, Babcock Rosyth, has held emergency meetings with Fife Council and the Scottish Environmental Protection Agency to find a solution to the problem.

So far the company has used one of its own suction tankers to remove some of the dead fish and has pumped oxygenated water into the basin to dilute the smell.

East of Scotland Water has also recommended that a deodorising agent be added to the water and that is likely to be tested over the next few days.

A proposal has been also been put forward to use a specialised vacuum dredger to remove the dead sprat from the sea bed but it could be up to two weeks before this is available.

'Health hazard'

Speaking on BBC Radio's Good Morning Scotland programme, North Queensferry Councillor, Jim Cook, said winds were carrying the smell well beyond the Rosyth docks.

"It's pretty bad. It's coming right up through North Queensferry and Inverkeithing," he said.

"It's a nauseating sort of smell. One which I'm a bit worried as to whether or not it's a health hazard."

Councillor Cook said that the smell resembled a gaseous emission from sewage and said that he was concerned it may affect people's health.

He added: "I think it's about time it was cleared."

Sprat average between 8cm and 10cm in size. They usually swim in enormous shoals and are common in the North Sea.

Commercially the fish is an important raw material for the canning industry, where it is marketed as sardines and anchovies.