The biggest population declines were in the Northern Isles, with reserves in Orkney showing significant drops in populations of sensitive species such as Arctic Terns and Kittiwakes. A full colony count at Marwick Head reserve on the Orkney mainland showed a staggering 53% decline in the total number of seabirds present since the last full census of the UK's seabird populations in 2000, and a 22% decline since the last colony count in 2006.

The Arctic Tern - Sterna paradisaea - is strongly migratory, seeing two summers each year as it migrates from its northern breeding grounds along a winding route to the oceans around Antarctica and back, a round trip of about 70,900 km each year. This is by far the longest regular migration by any known animal. They are mainly grey and white plumaged, with a red beak and feet, white forehead, a black nape and crown (streaked white), and white cheeks. The upper wing is grey with a white leading edge, and the collar is completely white, as is the rump. The deeply forked tail is whitish, with grey outer webs. The hindcrown to the ear-coverts is black.

The kittiwakes – genus – Rissa -  are closely related to the gull family Laridae. They have a white head and body, grey back, grey wings tipped solid black and a yellow bill.