What was done
The authors analyzed population sizes and phylogenetic and spatial structures of British and Irish seabirds based on "(1) presence or absence of the seabird species in the different counties of Britain and Ireland between 1875 to 1900 and 1968 to 1972, (2) seabird breeding censuses of Britain and Ireland from 1969 to 1970, 1985 to 1988 and 1998 to 2002, (3) at-sea abundance and distribution surveys of seabirds in the North Sea from 1980 to 1985 and 1990 to 1995, and (4) a bioenergetics model to estimate energy expenditures for 40 seabird species."

What was learned
Grandgeorge et al.'s work revealed, in their words, "a marked expansion in the breeding range of seabirds in Britain and Ireland between 1875 and 1972." In addition, they report that "total seabird numbers also increased at an average rate of 1% per annum between 1969 and 2002, with a related increase of 115% in predicted total seabird predation." What is more, they state that "between 1875 and 1972 no seabird species was lost and there was an overall expansion in breeding range of the seabird population of Britain and Ireland, with the number of counties occupied increasing from 31 to 47."

What it means
In the words of the six researchers who conducted the work, the results of their study indicate that "the seabird community of Britain and Ireland has been remarkably resilient to environmental change in the 20th century." In fact, they say it actually "prospered during the 20th century." In fact, they state that "significantly raised ocean temperatures in the North Sea (Beaugrand, 2004)" may even have "created more favorable [our italics] environmental conditions for some seabird species," citing the work of Thompson (2006).

Not quite the "end of the world" lamented by so many climate alarmists!

References
Beaugrand, G. 2004. The North Sea regime shift: evidence, mechanisms and consequences. Progress in Oceanography 60: 245-262.

Thompson, P.M. 2006. Identifying drivers of change: Did fisheries play a role in the spread of North Atlantic fulmars? In: Boyd, I.A., Wanless, S. and Camphuysen, C.J. Eds. Management of Marine Ecosystems: Monitoring Change in Upper Trophic Levels. Cambridge University Press, Cambridge, United Kingdom.