WATER and plankton collected from seas off the east coast of Scotland are being analysed by Scottish Government experts in a bid to solve the mystery of why over 1,000 dead seabirds have washed up in recent weeks.

An “unprecedented number” of seabirds -- mostly guillemots and razorbills -- have been found starved to death on beaches from Orkney down to the north and east of England since late August.

There have also been reports of large numbers of the same species feeding unusually close inshore, and venturing several miles up Scottish rivers searching for fish to eat.

The Marine Scotland directorate of the Scottish Government has now collected water and plankton samples from the seas off eastern Scotland from Aberdeenshire down to the Firth of Forth to investigate the possible presence of harmful algal species.

An algal bloom said to be “the size of a large county” has been identified off the north-east coast. Close to some key seabird feeding hotspots, one theory is that some of the beached birds may have been feeding there and picked up algal toxins via the food chain.

Samples collected by the marine protection vessel (MPV) Hirta are currently being analysed at the Scottish Government’s Marine Laboratory in Aberdeen to determine whether they contain toxic algae.

Scientists from the Marine Scotland directorate are also collating information on the abundance and quality of key prey fish populations to see if prey availability is a potential factor.

Tests carried out for avian influenza on a sample of the dead seabirds have returned negative results.

A Scottish Government spokesperson said: “We are aware of reports of unprecedented numbers of seabirds stranding on the Scottish coastline.

“We are working closely with a range of other organisations to investigate a number of potential causes of this unusual event.

“Vessels from the Scottish Government’s Marine Scotland directorate, collected water and plankton samples from the east coast of Scotland to investigate the presence of harmful algal species.

“These samples are currently being analysed and we will report the findings in due course.

“Further work is also ongoing to explore whether changes in prey abundance or quality are a potential factor.”

Dr Francis Daunt, seabird ecologist at the UK Centre for Ecology & Hydrology (UKCEH), said this week that the number of dead guillemots and razorbills reported had exceeded 1,000.

Dead birds were found to weigh 550 grams on average -- just half their usual body weight of 1,000-1,100 grams -- suggesting they starved to death at a time when conditions are generally good for the species.

Guillemots have also been reported searching for fish in very shallow waters, among swimmers and people wading in locations such as Portobello and Cramond, in Edinburgh.

Dr Daunt added: “This is very unusual behaviour not really seen before and, coupled with this tameness, we’ve also seen a lot of birds heading up rivers.

“We’ve had birdwatchers who have been following their patch for 20 years and they’ve never seen them before.

“We’ve even had some further upriver from Stirling -- a long long way from the sea. These birds seem to be desperate. They are calling, sitting on the river shore, not really doing anything because they are probably starving and they’re not able to find any food.”

The phenomenon comes on top of an already serious situation for Scotland’s globally important seabird populations.

 The latest NatureScot indicator, which tracks 11 seabird species, showed an overall decline of 49 per cent since 1986, which has been linked to climate change.

Members of the public who find sick seabirds should report their whereabouts to the Scottish SPCA.

Dead seabirds should be reported to the UKCEH.

The Scottish Government spokesperson added: “Wild birds can carry several diseases that are infectious to people, so members of the public should not touch or pick up any dead or visibly sick birds that they find along the Scottish coastline.”

  • Anyone who finds a sick or injured seabird in Scotland is urged to contact the Scottish SPCA on its dedicated animal helpline 03000 999 999. Dead seabirds should be reported to the UKCEH, which is collating data on the event, at https://www.ceh.ac.uk/form/general-contact-us