Grieg lice numbers down nearly 90%
SHETLAND based Grieg Seafood has recorded a drop of nearly 90 per cent in numbers of adult female sea lice over the last year.
Managing director Grant Cumming said a variety of factors, including new farming methods and colder sea temperatures, had helped to cut numbers of the parasite.
Grieg Seafood harvested 1,201 tonnes during the first quarter of 2018 in its region, which includes the isles as well as Skye, compared to 1,293 tonnes the previous year.
‘We produced a loss for the first quarter, which is disappointing, but we had a very low harvest volume, which is the main reason for showing a loss,’ Cumming said.
But there was an 87 per cent reduction in adult female sea lice in Shetland compared to the first quarter of 2017.
‘We’re making a lot of changes to how we farm fish,’ said Cumming, who recently appeared before the Scottish parliament’s Rural Economy and Connectivity committee, as part of its investigation into salmon farming in Scotland.
He explained to MSPs that he had consolidated Grieg’s operations, reducing the number of active farms, to help bring lice numbers under control, and creating longer fallow periods,
‘But in addition to that, being able to treat our sea lice with freshwater has made a big difference to us too,’ he told Shetland News. Cumming added that the sea in and around Shetland has been colder than the last four or five years, which has stunted the growth of lice. He said they are
also using ‘a lot of cleaner fish’.
‘And most of the sites are being stocked as well with something called a sea lice skirt, which is a six metre deep tarpaulin which goes around the pen.’