Big trouble for seabirds
Analysis of this year's seabird breeding data on RSPB (BirdLife in the UK) coastal reserves shows that Black-legged Kittiwake Rissa tridactyla, Arctic Tern Sterna paradisaea and Parasitic Jaeger Stercorarius parasiticus – more commonly known as Arctic Skua - have had a terrible season, with virtually no chicks reared to fledging in the far north of the UK. Changes in food supply, which may be linked to climate change, could threaten the future of these species in the UK.
The UK is internationally important for seabirds. Scotland alone is home to over three million seabirds, which is around 45% of the European Union’s breeding seabird population. Earlier this year, the RSPB issued a grave prognosis for the breeding season. Many internationally-important colonies had abandoned nests, and empty cliffs which should have been teeming with tens of thousands of seabirds were very quiet.
The new RSPB data confirm that many northern species have suffered major collapses in breeding success. Worryingly, the evidence again suggests that repeated annual breeding failures are now substantially reducing populations of those species worst affected.
While Black-legged Kittiwakes, Arctic Terns and Arctic Skuas have been hit very hard and face important declines, some other seabird species appear to be weathering the storm on RSPB reserves. Great Skua Catharacta skua, Northern Gannet Morus bassanus and Great Cormorant Phalacrocorax carbo have experienced modest increases in their numbers, while Herring Gull Larus argentatus have remained stable.
Although direct evidence is still lacking, increased winter sea surface temperatures disrupting the food chain are thought to be driving the declines.
Douglas Gilbert, an ecologist with RSPB Scotland, said: "RSPB reserves are acting as an indicator of the wider fortunes of seabirds around our coasts. The outlook for some species such as Arctic Skua, Black-legged Kittiwake and Arctic Tern is dire, and there are problems with other species like Common Guillemot Uria aalge and Atlantic Puffin Fratercula arctica in some areas too. Unless conditions change to allow these birds the chance of successful breeding, the long-term future for them is bleak. The evidence that this is linked to changes in sea surface temperatures is now growing”.
Icelandic seabirds are also experiencing similar problems. Fuglavernd (BirdLife in Iceland) reports that many seabirds have had extremely bad breeding seasons over the last four years. Icelandic seabird declines have coincided with a period of rapid increases in sea temperature - especially in south and west Iceland which is most exposed to the warming waters of the Gulfstream.
As in the UK, species which have suffered most are Arctic Terns, Black-legged Kittiwake, Atlantic Puffin, Great Skua and Northern Fulmar Fulmarus glacialis. Due to climate change, 18 new bird species have arrived in Iceland since the 19th Century.
Konstantin Kreiser, EU Policy Manager at the BirdLife European Division, commented: "This is an especially shocking example showing how urgently we have to strengthen our complex ecosystems in times of climate change. If governments do not take action against overfishing, pollution and greenhouse gases, we will face many more terrible surprises"
Created: 27th Nov 2008