The latest avian flu outbreak, which has led to the deaths of millions of domestic birds in the United States, has spread to wild seabird colonies in the United Kingdom. At least a thousand northern gannets in the world’s largest colony of such birds, in Scotland, have died from the illness. Avian flu has also spread to wild birds in Norfolk and the Farne Islands in England.
Seabirds already face multiple human-generated threats, including climate change, habitat destruction, prey shortages, invasive species, mortality in fishing gear and poorly sited wind turbines, Paul Walton, from the Royal Society for the Protection of Birds (RSPB), says in a Natural History Museum statement.
“Now, a highly mutable form of avian influenza, which originated in poultry, is killing our wild seabirds in large numbers,” he tells the museum. “We urge the U.K.'s governments to develop a response plan urgently—to coordinate surveillance and testing, disturbance minimization, carcass disposal and biosecurity.”
Seabirds are particularly vulnerable because they are long-lived with low reproductive rates, so even after the outbreak ends, the birds may take a while to recover, reports New Scientist’s Adam Vaughan. Many also nest closely to one another, increasing the chance that disease will spread.
“All seabirds have some type of influenza at some point in their life, and it's not that uncommon,” principal curator and curator in charge of birds at the Natural History Museum Alex Bond says in the statement. “This outbreak has become notable because of its large geographic spread and significant chick mortality. It's not just seabirds which are being affected either, but also waterfowl, waders and other birds which live in close proximity to one another.”
About eight million seabirds from 25 species call Britain and Ireland home, including 90 percent of the world’s manx shearwaters, 68 percent of northern gannets and 60 percent of great skuas. The Bass Rock houses over 150,000 gannets—a large seabird native to both sides of the Atlantic coast—in peak season.
The Farne Islands, which sit off the coast of Northumberland, England, announced a closure to visitors starting July 3 to reduce the risk of disturbance to the birds that live there.
"While we have no confirmed test results from the islands, we are now starting to see the terribly sad and distressing impact of avian influenza on our internationally important and threatened seabirds who make the islands their home,” per the announcement. “Seabirds such as Arctic terns nesting in dense colonies, most of which are already in decline in the U.K., are particularly vulnerable now as they have returned to the islands in their thousands to breed, nesting in close proximity to each other.”
Some Scottish islands have also closed to the public due to the outbreak: the Isle of May and Noss National Nature Reserves in Fife and the Isle of Noss in Shetland.
The avian influenza spreading in poultry and wild birds in the U.K. is an H5N1 subtype virus, which generally is confined to birds but has spilled over from time-to-time to humans. Human vaccines for the virus already exist and have been stockpiled by various governments.
The risk this bird flu poses to humans is low right now, with only two cases reported since October, Nature's Brittney J. Miller reported last month. But a mutation could make the virus more transmissible.
“These viruses are like ticking time bombs,” Ian Barr, deputy director of the World Health Organization, tells Nature. “Occasional infections are not an issue—it’s the gradual gaining of function of these viruses.”