Two major oil spills occurred in the last fiveyears in European Atlantic waters: the Erika, off Brittany in 1999 and the Prestige off Spain in 2002. Each killed many thousands of seabirds, principally guillemots, razorbills, puffins and gannets.

The Prestige alone may have killed 200,000 seabirds and out of a sample of 23,500 corpses checked by ornithologists, 132 bore rings that had been fitted to the birds by researchers at Irish and British colonies.

By far the largest proportion of these came from Great Saltee in southeast Ireland and most were ringed as young the previous summer. This tells us that there is a major movement, or migration, of our young birds to wintering areas off western France and Spain including the Bay of Biscay.

Luckily, adult birds tend to stay closer to home and they escaped the worst of these marine tragedies. Most seabirds, guillemots and razorbills included, do not start breeding until they are at least three years old.

However, counts of colonies in Ireland known to have been affected by these oil spills between 2002 and 2004 have not shown any real change in numbers and the conclusion appears to be that a very large proportion of birds raised must die, from natural causes or oiling, before they reach breeding age anyway.

Nevertheless, new European regulations insisting on double-hulls for tankers can only be good news for seabirds.

Photo above: pollution victim - a puffin found oiled on the Louth coast. Photograph: BirdWatch Ireland.