Another Scottish island has been advised to ban tourist landings in a bid to stop the spread of avian flu amid the deadliest outbreak in two decades.
The latest in a string of islands asked to close their gates, Mousa in Shetland is home to around 11,000 breeding pairs of European storm petrels, representing 2% of the entire global population of the birds.
The Mousa Boat will stop running trips to the island from July 30 for the remainder of the 2022 breeding season. Historic Environment Scotland is also going to close the island’s famous Iron Age broch until mid-October.
NatureScot has declared that the risk of visitors moving the avian flu virus around the island on their footwear and inside the broch is too great.
Storm petrels rarely mix with other seabirds, as they feed far out to sea during the day and only come ashore under the cover of darkness.
The virus that causes avian flu can survive for many days on bird faeces and soil, and there is a high risk of petrels landing and picking up the virus where visitors have walked both inside the broch and at other places where they nest on the island.
Eileen Stuart, NatureScot’s deputy director of nature and climate change, said: “Restricting visits to Mousa was not an easy decision, but we are increasingly concerned about the terrible effect avian flu is having in Shetland’s seabird colonies.
“Together with the Scottish Government and the Animal and Plant Health Agency, we have looked at biosecurity measures to allow the broch to remain open to the public while the storm petrels are nesting. However, the logistics of getting enough clean water out to the broch and ensuring that visitors can clean and disinfect their footwear adequately has proved too challenging for this season.”
Mousa becomes the 24th Scottish island to bar visitors from setting foot ashore over the outbreak.
Helen Moncrieff, RSPB Scotland’s Shetland manager, said: “We greatly appreciate the decision to stop running the boat service to Mousa to give the precious seabirds on the island the best chance of survival during this devastating outbreak of avian flu. Storm petrels breed all around the island, including the Broch, and draw thousands of visitors to the reserve.
“The impact avian influenza is having on tour operators is incredibly tough, particularly after the last few years. We are grateful for the sacrifices that The Mousa Boat company, and other tour operators elsewhere in Scotland, are making to help limit the spread.”
NatureScot said it will review its risk assessment in March 2023 in light of research into how avian influenza virus spreads on different surfaces and information about the predominant strain of the virus circulating in wild bird populations.
This information will be used with the aim of devising effective biosecurity measures to keep Mousa Broch open to visitors while protecting the storm petrels from avian flu.