Lice levels hit 6-year high
The numbers of adult female sea lice in Norwegian farms was at its highest level for week 28 since 2010.
According to the latest lice data, during week 28 the country’s average lice level was 0.17 sexually mature female louse per fish – the highest level since 2010 when it was 0.27 in the corresponding week. However, it is slightly below the average for 10-year period before (2006-2015).
As usual louse densities varied considerably, with the highest levels in the three southernmost counties. Hordaland was the highest, with an average of 0.28, while South Trøndelag averaged 0.24 sexually mature females.
Meanwhile More og Romsdal saw a marked decline, with 0.16 sexually mature females, compared with 0.26 the same week last year.
Water temperature
The water temperature is also slightly above the average for the last ten years, averaging 12.6°C – the highest level in week 28 since 2009, when it averaged 12.7°C.
However, this can’t be the only reason behind the lice levels, as the largest deviations above average were in More og Romsdal and north, while the temperatures south of the Sognfjord are actually below their average.
