ISA suspected at Norway salmon farm [Norway]

Undercurrent News
September 30, 2014

Infectious salmon anemia is suspected at a farm owned by Nordlaks Oppdrett in Nordland, Norway, said the Norwegian Food Safety Authority.

The veterinary institute informed the NFSA about the suspicion after a sample tested positive on Sept. 26. New tests are being taken to verify the initial finding.

Norway recorded ten outbreaks of ISA in 2013 of which eight were in Nordland. That was up from just two in 2012, and the highest level seen since at least 2009, when there were nine.

Nevertheless, pancreas disease remains the biggest viral disease affecting salmonid farms in the country. PD outbreaks were down 28% in 2013, but remained significant with 99 instances recorded during the year.

Read the full article in Undercurrent News.

Posted September 30th, 2014

Scientist makes breaktrough in sealice research [Norway]

Undercurrent News
September 30, 2014

A scientist has detected a gene that that is responsible for making sealice resistant to anti-lice products, in a breakthrough finding that has allowed reported the Norwegian newspaper Dagens Naeringsliv.

The finding has led to a method that allows farmers to quickly detect resistant lice and adapt delousing processes accordingly.

Molecular biologist Kiran Kaur at the Norwegian School of Veterinary Science (NVH) found that the mutated gene is responsible for lice’s increasing resistance to the most widely used anti-lice products, Salmosan and Trident, said the newspaper.

She found the mutation while investigating the difference between resistant and non-resistant sealice.

Using her findings, the biotechnology firm Patogen Analyse then developed a method to be able to detect the mutation in a speedy and simple way.

Former methods to identify resistant lice took long time, were fraught with errors and required the lice to be alive for testing.

In contrast, the new method allows farmers to put the lice in ethanol, send it by post and receive the results within two to three days.

Read the full article in Undercurrent News.

Posted September 30th, 2014

Harmful Algal Bloom Causes Big Losses at Marine Harvest Salmon Farm

The Fish Site
September 30, 2014

Marine Harvest Canada (MHC) is estimating a loss of up to 280,000 fish of an average weight of 4.1 kilograms due to a harmful plankton bloom at Marsh Bay near Port Hardy, BC.

Harmful plankton bloom reported at Marine Harvest Canada salmon farm

The harmful algae, Heterosigma akashiwo, are common plankton known to kill salmon.

Originally reported on MHC's website on May 27, the company's salmon farms have been on high alert for harmful plankton all summer.

"We've had over three months of sunny days, and have watched the plankton grow in many of our operating areas over this time," said James Gaskill, Production Director.

"Our mitigation systems, which include tarps and aeration, have worked very well in all other regions but just couldn't overcome this extreme and rare bloom."

A recent change in weather has reduced concern of further blooms, and mortality has ceased at Marsh Bay.

The company maintains insurance to cover this type of rare event.

MHC is British Columbia's leading salmon aquaculture company, producing 40,000 tonnes of fresh, farm-raised salmon at sites on and around Vancouver Island.

Read the full article on The Fish Site.

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Posted September 30th, 2014

Crack in Mount Polley mine’s dam noted in 2010 inspection report (with report)

Vancouver Sun
September 26, 2014

A 2010 dam safety inspection at the Mount Polley gold and copper mine identified several concerns, including the discovery of a 10 to 15-metre long “tension” crack in the earthen dam.

The crack was discovered in the perimeter wall, the same embankment where a section failed Aug. 4 of this year, releasing millions of cubic metres of water and tailings containing potentially toxic metals into Hazeltine Creek and Quesnel Lake.

“A tension crack does not necessarily indicate a plane of weakness in fill materials but it can’t be ignored either,” Knight Piesold, the company’s geotechnical engineering firm at the time, said in its report obtained by The Vancouver Sun.

Knight Piesold recommended a stability assessment be carried out, and told the company the crack should have been reported to them immediately. It was noticed by a grader operator two months before the engineer’s inspection on Oct. 7, 2010, and had been partly covered over with dirt.

No signs of distress were identified at the tailings embankments other than the tension crack, the report said.

Other concerns identified by Knight Piesold included that 40 per cent of 92 instruments that measure water pressure in the dam were broken and needed to be replaced before the height of the dam was raised. The height of the dam is raised on an almost continual basis to contain rising levels of water and tailings.

Replacing the instruments, called piezometers, had already been identified as an issue in 2006 during a more detailed dam safety review conducted by engineering firm AMEC.

The 2010 report offers the first documented details of concerns that had been raised specifically about the tailings dam at Mount Polley mine.

Until now, concerns raised after the dam’s collapse have focused on the challenges the mine faced in dealing with too much water in the tailings storage facility.

It is unknown if the concerns raised in 2010 were addressed by Imperial Metals.

Read the full article in the Vancouver Sun.

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Posted September 26th, 2014

MSD Animal Health Shows Benefits of Treating Salmon Sequentially with SLICE® and Hydrogen Peroxide

The Fish Site
September 26, 2014

MSD Animal Health (known as Merck Animal Health in the USA and Canada) recently presented results from a study assessing the benefits of treating salmon with SLICE® (emamectin benzoate) followed by hydrogen peroxide to reduce sea lice infestations and re-infection in sea lice populations that have demonstrated resistance to emamectin benzoate.

The study found that a sequential treatment approach provided effective clearance of existing sea lice infections and subsequently reduced resettlement of an emamectin benzoate-resistant sea lice strain, more effectively than treatment with hydrogen peroxide alone. Results were presented at the 10th International Sea Lice Conference being held 31 August to 5 September in Portland, Maine, USA.

“Sequential treatment with SLICE and hydrogen peroxide has been adopted by a number of veterinarians and producers to improve sea lice control, particularly in sea lice populations that have shown resistance to the treatments,” said Dafydd Morris, MSD Animal Health.

“We are pleased to present this important research to help producers optimise their sequential treatment approach, thereby improving the effectiveness of their control strategy and reducing re-infection.” 

In the study, mixed-sex Atlantic salmon were challenged with infective sea lice copepodids from a population that is resistant to emamectin benzoate. After four weeks, the fish were randomly allocated to 28 identical treatment tanks. On Day 36, the fish were challenged with a second cohort of sea lice copepodids to ensure a mixed-stage sea lice population on the fish. 

Read the full article on The Fish Site.

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Posted September 26th, 2014