Aquaculture equipment manufacturer Egersund Net has patented its ‘snorkel net’ system for farming salmon deep below the surface of water – where sea lice levels dwindle significantly – while still allowing them access to air.

Patented in Norway as the ‘TubeNet’, the technology is now available commercially, though Norway’s Institute of Marine Research (IMR) continues to run new tests, researcher Lars Stien told Undercurrent News.

Testing at new and varied depths, preliminary data once again looks promising, he said.

In summer 2014 tests with the snorkel nets yielded results of less than 0.5 sea lice per fish, compared to results of an average 11 sea lice per fish in control pens.

Patents on the TubeNet are pending in several other countries, said Egersund Net R&D manager Geirmund Vik, and several locations on the south coast of Norway have been utilizing the installations in 160m cages as of May 2014.

“The positive findings from the trials at IMR in 2011- 2014 are now verified in full-scale farming,” he said. “The Egersund TubeNet has experienced hurricanes, and has proven to withstand the forces of nature.”

“The sea-lice pressure have been low so far this winter, but sea-lice levels are lower than reference cages. The real proof will come in the next few months, and we are sure it will be good.”

Three more farms are in the testing stage, and improving the system is a continuous process, he noted.

The commercialization process starts just as Norway is investigating the escapes of at least 120,000 salmon following the winter storm Nina, that hit the west of the country in early January.

Coupled with a continuing struggle to keep sea lice levels manageable, now is a good time to be selling a secure and environmentally-friendly answer to the pest problem.

Last week farmers Bremnes Seashore and Nova Sea were told the total allowable biomass at three of their sites would be cut in half due to sea lice numbers.

The move is part of tough new measures introduced by the Norwegian Food Safety Authority to fight sea lice.