For the Birds Radio Program: Bird Tragedies
The sandeel population in the northern Atlantic crashed, probably more due to warming waters than overfishing, and this led to an unprecedented crash in seabird breeding in many places.
July was a tragic month for birds. Hundreds of thousands—perhaps more than a million—Scottish seabirds failed to breed this summer in a wildlife catastrophe which is being linked by scientists directly to global warming. The massive and completely unprecedented collapse of nesting attempts by several seabird species in Orkney and Shetland is being attributed to a rise in sea temperature, which is believed to have led to the mysterious disappearance of the sandeel, a small fish whose huge numbers sustained larger fish, marine mammals and seabirds in their millions.
In Orkney and Shetland, sandeel numbers have been shrinking for several years, and this summer they disappeared completely, leading to mass starvation for the seabirds. Guillemots, elegant birds of the northern seas that look like slender penguins, produced almost no young at all according to the Royal Society for the Protection of Birds. In 2000, more than 172,000 breeding pairs of guillemots were recorded in the islands, so zero production of young is shocking. Martin Heubeck of Aberdeen University, who has monitored Shetland seabirds for 30 years, said: “The breeding failure of the guillemots is unprecedented in Europe.” More than 6,800 pairs of great skuas—the largest jaegers—were recorded in Shetland in the same 2000 census; this year they have produced fewer than 10 chicks, while the arctic skuas failed to produce any surviving young at all.
The 24,000 pairs of arctic terns, and the 16,700 pairs of tiny gulls called Shetland kittiwakes have “probably suffered complete failure.” It is likely that Atlantic puffins that nest in this area will also have suffered massive breeding failure but because they nest deep in burrows, this is not immediately obvious.
But the astonishing scale of what has taken place is already clear - and scientists are openly making a link to climate change. Apparently the microscopic plankton on which the tiny sandeel hatchlings feed are moving northwards as the sea water warms, leaving the baby fish to starve.
This is being seen in the North Sea in particular, where the water temperature has risen by 2 degrees Centigrade in the past 20 years, and where the whole ecosystem is thought to be undergoing a fundamental alteration in the interaction of its component species. Euan Dunn of the Royal Society for the Protection of Birds writes, “Think of the North Sea as an engine, and plankton as the fuel driving it. The fuel mix has changed so radically in the past 20 years, as a result of climate change, that the whole engine is now spluttering and starting to malfunction. All of the animals in the food web above the plankton, first the sandeels, then the larger fish like cod, and ultimately the seabirds, are starting to be affected.”
Although over-fishing of sandeels has caused breeding failures in the past, the present situation could not be blamed on fishing, he said. The Shetland sandeel fishery was catching so few fish that it was closed as a precautionary measure earlier this year. “Climate change is a far more likely explanation.”
The spectacular seabird populations of the Northern Isles have a double importance. They are of great value scientifically, holding, for example, the world’s biggest populations of great skuas. And they are of enormous value to Orkney and Shetland tourism, being the principal draw for many visitors. The national and international significance of what has happened is only just beginning to dawn on the wider political and scientific community, but some leading figures are already taking it on board.
“This is an incredible event,” said Tony Juniper, director of Friends of the Earth. “The catastrophe [of these] seabirds is just a foretaste of what lies ahead. It shows that climate change is happening now, [with] devastating consequences here in Britain, and it shows that reducing the pollution causing changes to the earth’s climate should now be the global number one political priority.”
There are a great many people who don’t consider the loss of birds, even entire species, a tragedy. But like canaries in a coal mine, these oceanic birds are giving us a preview of what can happen to us if we don’t get to work reducing the pollutants that cause warming. The earth’s human population continues to grow. As more and more oceanic fisheries crash, more and more people will starve, and global unrest will grow. The greatest strides of our society, from inventing electricity to putting people on the moon, were made only because we took scientists seriously. We ignore them now at our peril.