Norway salmon farms told to urgently find solutions to rising sealice levels
October 6, 2014, 6:18 pm
Throughout the summer, farms overall kept the lice levels below the regulated limit of 0.5 adult female lice per salmon.
However, in any given week, an average of 7.5% of farms were above the limit, ranging from 2% to 15%, said NFSA.
Many farms have at some point exceeded the prescribed limit at some point, said the authority.
“The level of excess varies significantly, but that 10 to 15% of farms during some periods are above the allowed limit is too much,” said NFSA’s supervisory director Kristina Landsverk.
The rising pressure means heavier costs in the form of more treatments, more medications, worse fish health and also rising pressure for wild trout, said Landsverk.
Increasing resistance to drugs means in many instances, farmers’ only left resort to combat the lice is harvesting.
Preliminary data from Norway’s Institute of Marine Research indicates that most of the wild salmon smolt found its way to the sea without too much impact from sealice.
However, levels on wild trout increased significantly in June and July, in large areas from Hordaland to Helgeland in Nordland.
The lice pressure on wild trout was generally high during the summer, said NFSA.
The authority said it has renewed its focus and efforts on monitoring lice.
“The sealice situation is starting to get out of control in many areas,” said Landsverk. “NFSA will therefore consider reducing the number of fish in the sea in critical areas.”
Alternative solutions to combat lice are urgently needed, she added. “Work on this must be further intensified.”