Arctic Tern with sandeels at Deerness View more photographs at www.orkneyphotographic.co.uk
by Hamish Auskerry
The seabird population across the UK has fallen by over half in the last 25 years with some of the worst declines seen on the cliffs of Orkney.
One of these areas is Noup Head on Westray where the formerly 150 pair-strong population of Guillemots and Kittiwakes failed to successfully breed a single chick in 2012.
The Kittiwake was seemingly the worst affected species, with recent research carried out by the RSPB and The Joint Nature Conservation Committee (JNCC) on the so called, ‘seabird cities' showing an alarming decrease of 82% among breeding pairs in just over a decade.
Experts believe that the decline in seabird populations is an indication of the poor health of the ecosystem and that the temperature increase in North Sea waters is due to global warming.
Former RSPB Scotland’s Orkney Area Manager Eric Meek told ONT: "This is going to have a knock on effect, not just for seabirds, but for the whole environment, of which man is a part.
"At the moment, the marine ecosystem is in a very poor state".
Further research also shows a decrease of two-thirds of the Scottish population of Kittiwake since the mid 1980s and by over half across the UK as a whole.
The last full census of all the UK's seabirds also revealed a decline in numbers at the Marwick Head reserve in Orkney of over 50% since the year 2000 and a 22% decline since the last colony count in 2006.
As part of their ‘Single Outcome Agreement', Orkney Islands Council have stated that the indicator of a healthy marine ecosystem is an average of one successfully bred Kittiwake chick per adult pair each year, however, that level has now dropped to 0.3 per pair per year.
The reason for this decline has been attributed to the lack of availability of sandeels for seabirds in North Sea Waters.
Rising sea temperatures
Steve Sankey of ‘Orcadian Wildlife', who has run nature tours around Orkney for 10 years, told Orkney News Today: "The sea temperature has risen by about a degree and that seems to have been enough to move the sandeels away, or they have just failed to breed".
Chris Booth, the Orkney Recorder for Cetaceans and a bird counter in Orkney for the British Trust for Ornithology for over 40 years said: "It's still too early to say about Climate Change and how much of an affect it is having on different species, but it's almost certainly a factor."
Sandeels, which feed on Plankton, are key to the North Sea ecosystem and a severe depletion of stocks will have considerable knock on effects for local tourism, the fishing industry and seabird survival.
Wildlife contributes millions of pounds to Orkney’s economy
In 2000, the RSPB estimated that Wildlife tourism accounted for £1.3 million (7%) of the £18 million made in revenue from the 81,000 summer visitors to Orkney that year.
"I strongly suspect that the overfishing of sandeels has had an effect; they underpin the whole food chain, second only to Plankton", Steve Sankey told ONT
"The present-day trawlers can catch so much in one go, they've taken away a lot of the adult fish so you don't have the breeding fish anymore" said Chris Booth.
A recent report by the International Council for the Exploration of the Sea (ICES), who advise the European Union on fishing quotas, advised that catches of sandeels in 2013 in the waters off the East coast of Scotland should decrease by a "precautionary buffer of 20% in relation to the 2012 catch, leading to catches of no more than 2041 tonnes".
This comes after their figures showed a high breeding success of sandeels in 2009, followed by much lower breeding success. They say that recent catches have been very low despite some increase in 2012.
The ICES have said a local depletion of sandeel stocks at a distance less than 100 km from seabird colonies may affect some species of birds, especially ‘splash divers' such as Kittiwakes and Arctic Terns, whereas the deeper diving seabirds and fish may be less vulnerable.
Despite this, Guillemots, which are deeper diving seabirds, have also struggled in the last decade.
Their numbers seemed to hold up for longer than some of the other species of seabird but in 2004, their breeding success halved and although numbers were better in 2005/06, another disastrous summer the following year opened up large gaps in the once thriving colonies at Marwick Head and Copinsay.
Arctic Tern numbers have suffered over recent years
Arctic Terns have also suffered: "I remember when I first came to Orkney, if you went to Papa Westray, you would struggle to see the sky for the blizzard of Terns", said Steve Sankey.
However, their 33,000-strong population of breeding pairs recorded in Orkney in 1980 have crashed by three-quarters over subsequent decades. In light of recent studies linking low sandeel availability to poor breeding success of the Kittiwake, all commercial fishing in the Firth of Forth has been banned since the millennium, except for a limited opening to fishing in May and June of each year to monitor the stock.
There has never been a significant sandeel fishery near Orkney, however some Shetland boats did try fishing in Orkney waters on occasion when there was a Shetland based fishery back in the 1980s.
Nearest sandeel fishery to Orkney was off Fair Isle
The nearest grounds to Orkney that were fished were to the east and west of Fair Isle. However, there have been virtually no reported catches either there or in Shetland waters since 2004.
Sandeels are also caught for use as fishmeal and have been used in power stations in Denmark but the number of Danish and Norwegian vessels looking to catch sandeels has fallen by over half and two thirds respectively in the last decade.
According to the RSPB the seas around the UK's coast are: "increasingly overfished, over-trafficked and over-developed, but crucially under-protected".