Blog post by Sabine Schmitt, Senior Resarch Assistant, RSPB Centre for Conservation Science.
Volunteers out in force
Over the last two weeks almost 600 volunteers have braved the elements and surveyed around 2,000 km of UK and Channel Island beaches. Why?
It’s all part of the UK Beached Bird survey. The intrepid volunteers have been recording the numbers and species of seabirds found dead on these beaches. Added to this, they record the presence of oil on the birds and/or if there was any oil on the beaches they surveyed.
Once surveyed, they send their findings to us, and these are collated giving a picture across the whole UK. While this year’s results won’t be available for some time, we are hopeful that the trend of a decline in dead and oiled seabirds found during the survey will continue.
Last year’s survey found the fifth lowest density of dead seabirds since 1991 and the third lowest oiling rate in 27 years.
Trends in overall density of dead auks, gulls and cormorants/shags recorded between 1991 and 2017 – note the mass-mortality events of 1994, 1996 and 2014
Chronic oil pollution
In early January this year the collision of the Sanchi and the CF Crystal in the East China Sea led to an oil slick of more than 300 sq km. Major shipping accidents such as this, where a relatively large amount of oil is released at one site, grab the headlines and have unfortunately happened off the UK’s shores in the past.
However, the analysis of oil samples taken from oiled birds shows that most oil pollution in the North Sea can be assigned to illegal discharges of oil-sludge during shipping operations and leakages of oil by off-shore installations. And it is this chronic oil pollution which the UK Beached Bird Survey was set up to monitor in the 1970s.
The survey has been running in its current format of one annual mid-winter survey since 1991, and is organised by the RSPB and in Shetland by the Shetland Oil Terminal Environmental Advisory Group (SOTEAG).
A shag, one of the species recorded during the Beached Bird Survey
Monitoring contributing to a reduction in oil pollution
Systematic surveys of beached bird corpses have documented the effect of oil pollution around the North Sea coast for decades.
They have delivered useful information on the state, causes and extent of marine pollution and contributed to a number of measures to reduce oil pollution in the marine environment. These include the installation of oil reception facilities in all major ports around the North Sea and the designation of the North Sea as a Special Area according to MARPOL Annex 1 in 1999.
A gannet in flight, another one of the species looked for during the Beached Bird Survey
When the systematic beached bird surveys started along the Belgian North Sea coast in 1962 the oiling rate of all seabirds washed ashore there was over 90%. According to a recent study, this has now fallen to less than 20%. A similarly drastic decline was noted in The Netherlands.
For the whole of the UK coast oiling rates were never that high as the survey includes large areas of coast less polluted than the English Channel, the busiest shipping lane in the world. Nevertheless, the reduction in UK oiling rates from an average of 15% throughout the 1990s to now less than 5% of all dead seabirds found is still remarkable.
We will continue to monitor chronic oil pollution through the Beached Bird Survey and hope to see a further reduction in the number of oiled seabirds washed ashore in future.
For more on our science, check out the RSPB Centre for Conservation Science web pages.