SCOTLAND'S anglers are claiming wild sea trout are being "eaten alive by fish-farm parasites in an area where sea lice numbers are nine times industry lice thresholds.

The Salmon & Trout Association (Scotland) (S&TAS) says monitoring in June of juvenile wild sea trout in Little Loch Broom in Wester Ross has revealed fish carrying huge and probably lethal numbers of the parasitic sea lice Lepeophtheirus salmonis.

Some 46 juvenile sea trout were monitored over six days and the average number of sea lice per fish was 133 with many carrying more than 200 and two more than 500.

A burden in excess of 13 pre-adult sea lice is known to compromise severely the survival of juvenile sea trout, according to the organisation.

It says this comes from information supplied by the farms themselves, published by the industry body the Scottish Salmon Producers' Organisation (SSPO) which provide area, but not farm-specific, sea lice count data.

The S&TAS says it is impossible to identify definitively the source of this "explosion of juvenile lice numbers in Little Loch Broom".

However it believes that it is aware of the likely source of the lice.

However, Dr John Webster, SSPO's technical director, said the farm in question did not want to comment but was already planning improvements.

"However, over the last four or five years the S&TAS has accused salmon farming, wherever it is, of devastating sea trout and salmon," Mr Webster said.

"We have published the figures they have been seeking and all they can do is to pick out one farm from hundreds and says it proves their case.

"They are making no comment on all the data from all the others It is just more of the same."