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Tough Tactics Against Sea Lice & Fish Escapes

A new study by Norway’s Institute of Marine Research shows that sea lice and escaped salmon pose the most important risk factors to the sustainability of Norwegian fish farming. The government has taken a proactive approach and is in the...

The Institute’s report, published in January, found that the sustainability of the Norwegian aquaculture industry between the counties of Rogaland and Troms is being challenged by infection pressure of sea lice on wild salmonids and the possible genetic impact of escaped salmon.

Fish escapes happen for many reasons. The main ones are facility lapses and breakdowns, but they also occur because of flotsam in the sea, predators and boats running into the facilities, according to the Norwegian Seafood Federation.

Norway has been successful in dramatically bringing the numbers down. After reaching a peak of 921,000 salmon escapes in 2006, the Seafood Federation declared in 2007 a zero vision for escaped fish. By the end of that year, the numbers dropped to 290,000.

Norway is in the process of tightening its comprehensive
technical standards for fish farming installations.
© Norwegian Seafood Export Council/Per Eid

Combating Escapes

However, there is still reason for concern. There has been a recent spike from 2008 to 2010, during which the number of escapees rose from 111,000 to 252,000, according to the Norwegian fisheries directorate. As a result, Norway’s Ministry of Fisheries and coastal Affairs in January proposed a new legislation that will tighten Norway’s already strict regulations on floating fish farm installations.The country currently has the world’s most comprehensive technical standard for fish farming installations based on the NYTEK standard from 2004, according to Yngve Torgersen, deputy director general at Norway’s ministry of fisheries and coastal affairs. NYTEK requires that all new fish farms have a product certificate that shows they are in accordance with the technical requirements in NS 9415. These requirements outline how the different components of floating fish farms should be produced in order to withstand wind, waves and sea currents.The requirements were revised in 2009, thus prompting the need to change the NYTEK legislation. The government’s new proposal takes into account the experience from the past 5-6 years and calls for moorings to be subject to product certification, rather than manufacturer certified, as it is today. It also requires a complete farm certificate for assessing the totality of the floating installation, an assessment of the site and mooring by an accredited body before the floating installation is installed, and repairs of the net pen to be done by a certified repair shop.

“It is also very important to strengthen the work with preventing farmed fish escapes,” said Lisbeth Berg-Hansen in her speech at the Seafood Days conference in January where she proposed the new regulations. “After several years with a fall in escapees, we have seen in the past three years a small rise in the number of escaped salmon…The most important thing is that there are put demands on an installation certificate for all floating installations.”

The Institute of Marine Research recently successfully
mapped the salmon louse genome. Pictured here is
an auto-fluorescent image of a sea louse.
© Institute of Marine Research/Sussie Dalvin’ 

Preventing Disease

The Minister simultaneously announced a government proposal that calls for increasing the weight of fish up to 1 kilogram in 20% of the production capacity of smolt production licenses for salmon, rainbow trout and trout. That means fish would spend more time in the land-based smolt production plant. This could reduce the risk of escapes because fish would be more robust before they are transferred to sea, which could in turn reduce problems with disease and mortalities. The risk for sea lice, for example, is largest in the fishes’ early growth phase.The sea louse is one of the biggest problems plaguing the aquaculture industry. It is a naturally occurring external parasite that uses salmonids (salmon, trout, rainbow trout and Arctic char) as its host. It attaches to the skin of the fish, where it can cause wounds that lead to problems with the salt balance and result in infections.The Norwegian seafood industry has taken several measures to tackle the growing problem. Last year, the government spent NOK 40 million on research and development on salmon lice. The Norwegian Research Council and the Fishery and Aquaculture Industry Research Fund have put NOK 66 million toward sea lice projects. In addition, Norwegian companies such as Marine Harvest, Nordlaks, Aqua Gen and Seafarm Pulse Guard have helped finance R&D efforts.

Marine Harvest recently funded a project by researchers at the Institute of Marine Research, the University of Bergen and Max Planck Institute for Molecular Genetics to map the salmon louse genome. The mapping was completed in January and made public. The data is expected to play a major role in the development of a salmon louse vaccine and chemical lousing treatments. A genome database could save researchers time when developing new delousing methods.

Another example is a project established in January by the Norwegian Research Council to test the Seafarm Pulse Guard technology developed by Norwegian company SFD. The system works by creating an electrical current in the sea around the fish farming plants to stop sea lice from entering the cages and infecting the salmon. If successful, the Seafarm Pulse Guard could become a chemical-free alternative that may reduce the use of medical treatments for sea lice.

The Norwegian Research Council will also be active in establishing a Salmon Louse Research Center at the University of Bergen, which was newly created in December. The aim is for the centre to become the world’s leading research institution on sea lice and similar parasites and shorten the time from research and development to products ready for implementation. The Norwegian School of Veterinary Science and the Institute of Marine Research will participate as research partners, and Novartis Animal Health, EWOS Innovation, PatoGen Analyse, Marine Harvest and Lerøy Seafood Group as participating companies