Data for year comparison bird paper Feather isotope data for razorbills and puffins collected during breeding seasons in 2008 and 2015. Isotope data represents winter 2007/08 and 2014/15 Data logger coordinates for both years and species Pipefish isotope data used to make pipefish isoscapes. Pipefish abundance data - comparison between years Herring, sprat and sandeel abundance data. North Sea Isoscape raster surfaces used for assignments.