Unprecedented spread of salmon disease 12/10/12
Amoebic Gill Disease (AGD) exists in warm climates such as Australia, USA, Chile, Spain and France for many years but only turned up as a threat in the UK and Ireland very recently.
Scientists are puzzled at the rapid spread of the disease in Scotland and theorise if the parasite has changed or if environmental conditions have altered.
Water temperature and salinity levels are contributing factors.
The dry summer in the north of Scotland with little rainfall leading to increased salt levels in sea lochs has apparently created the crisis.
AGD is rife in virtually all sea farms across Lewis, Harris and Uist. It is also affecting Skye, Argyll, Shetland and Orkney.
Industry body, the Scottish Salmon Producers Organisation (SSPO) said: “The treatment being used, highly diluted Hydrogen Peroxide (H2O2), transforms to water and oxygen in the water and is entirely safe for both fish and the marine environment.”
Marine Harvest spokesman Steve Bracken said: “In June and July weather conditions in the Western Isles were very unusual. As a result we experienced much higher seawater temperatures and higher salinity levels than is the norm which has led to an increase in amoebic gill disease (AGD).
“Although the amoebae is harmless to humans, and present in seawater all over the world, high levels of it would eventually suffocate the fish, so it can’t be left untreated.
“AGD is treated using either freshwater or hydrogen peroxide. The hydrogen peroxide is harmless and is often used in toothpaste and shampoo. In the salmon pens it rapidly breaks down into water and oxygen.
“As it’s an oxidising agent it has to be transported in specialist tankers and we have taken steps to explain to the local community why there are additional tankers on the road.”
A spokesperson for The Scottish Salmon Company said: “Amoebic Gill Disease (AGD)
is a naturally occurring water-
“Once present, AGD can take hold and cause significant loss of fish and there have been instances of AGD affecting fish health across the industry recently.
“At The Scottish Salmon Company we take the health and wellbeing of our fish very
seriously and work rigorously to protect the natural environment and eco-
“We undertake daily health checks and where an incidence of AGD is discovered we act quickly in accordance with industry best practice guidelines, our own exacting veterinary procedures and Government regulation through our Marine Scotland licence.”
The SSPO says salmon farming is one of biggest private employers in the Highlands and Islands of Scotland.
The industry has injected over £1.4 billion into the economy during the last four years with over 500 new jobs created during the last three years.
Salmon farming in Scotland directly employs 2,124 people and thousands more jobs in the salmon supply chain.