The fish-eating guillemots have been washing up on beaches in the Netherlands
However the sudden bird deaths have not been reported in Belgium or Germany
Scientists are planning a mass autopsy in an effort to shed light on the mystery
PUBLISHED: 15:20, 6 February 2019 | UPDATED: 15:46, 6 February 2019
Dutch scientists have been left baffled after 20,000 dead or dying seabirds washed up on North Sea beaches in a phenomenon not seen for decades.
The fish-eating guillemots have been washing up between the northern Wadden Islands and southwestern Zeeland - all showing symptoms of severe starvation, a marine biologist said.
However the bird deaths are confined only to Dutch shores, with nothing reported in Belgium or .
Scientists are now planning a mass autopsy of hundreds of dead birds next week, hoping to shed more light on the mystery.
'What's killing them is the million-dollar question,' Mardik Leopold, a maritime researcher for Wageningen University, told AFP.
'And we still don't know what the answer is. It's an alarming situation,' he added.
'The last time we saw high mortality rates like this was in the 1980s and 1990s.'
High winds and stormy winter seas also could affect the birds' feeding patterns on herring and sprat as they become too fatigued to eat, Leopold said.
'But again, why are the deaths only localised to the Netherlands? Surely we're not the only place experiencing winter weather?' said Leopold.
Dutch media have raised the question of whether the deaths may be linked to a recent container spill, littering the Dutch and German coast lines with debris, including plastic toys, polystyrene, shoes and at least one bag with a dangerous powder identified by authorities as 'organic peroxide.'