The number of seabirds is falling because there is not enough protected sites for them to feed in the North Sea, the RSPB has warned.

The conservation charity is concerned about the future of birds such as puffins, shearwaters, kittiwakes, terns and gannets off the coast of East Anglia. It said not enough consideration is being given to feeding sites amid the hive of activity off the east coast, which includes shipping, renewable energy projects and the ship-to-ship oil transfers off Lowestoft to Southwold.

Mike Jones, an RSPB Conservation officer in the east, said seabirds numbers were falling because of the 'woefully inadequate' number of protected feeding sites.

'Thankfully, most seabird nesting sites in the region like North Denes in Great Yarmouth and the Alde Ore Estuary in Suffolk are already protected, but the areas where seabirds feed at sea are not, meaning that species like little terns, lesser black-backed gulls and sandwich terns are only generally afforded protection on land,' he said.

'This is nonsense – it's like having robust laws preventing burglary, while having no laws preventing mugging. It is astonishing that none of the sea, from Great Yarmouth to Felixstowe, has been put forward as a marine conservation zone.'

The sign the RSPB petition urging Government ministers to protect seabirds visit www.rspb.org.uk/marinepetition.

Defra said it is working to deliver a 'robust network of marine protected areas' to support a range of species and habitats using the sea.