Ecological Archives E092-019-A1

Per Fauchald, Henrik Skov, Mette Skern-Mauritzen, Vera Helene Hausner, David Johns, and Torkild Tveraa. 2011. Scale-dependent response diversity of seabirds to prey in the North Sea. Ecology 92:228–239.

Appendix A (TABLE A1). Summary of sample size and spatial distribution of winter observations from the ESAS, IBTS, and CPR databases in the period 1981-1999. ESAS is the European Seabirds At Sea database of strip transect counts of seabirds from ships. Sample units are 20 km strips (0.3 km wide). Data are from 1. October – 31 March. IBTS is the International Bottom Trawl Survey, which is a yearly trawl survey of fish. Sample units are individual trawl hauls. Data are from 6. January – 31.March. CPR is the Continous Plankton Recorder operated by Sir Alisdair Hardy Foundation. Sample units are CPR samples (ca. 18.5 km of towing). Data are from 1. October – 31 March. Average nearest/longest distance is the average longest and average shortest distance between observations within years.

  ESAS   IBTS   CPR
Year N Average nearest distance (km) Average longest distance (km)   N Average nearest distance (km) Average longest distance (km)   N Average nearest distance (km) Average longest distance (km)
1981 174 11 530   335 18 768   481 6 731
1982 779 6 853   359 17 824   344 9 675
1983 129 9 724   426 16 827   403 9 692
1984 219 10 825   452 15 825   300 11 695
1985 332 12 798   496 15 826   491 6 707
1986 363 9 812   510 14 837   329 5 715
1987 348 9 900   525 15 821   449 5 734
1988 1057 6 805   391 17 824   378 4 692
1989 872 7 831   415 17 818   393 6 701
1990 612 9 844   371 17 825   410 2 724
1991 535 9 881   409 17 826   378 4 728
1992 673 9 881   367 18 834   365 5 722
1993 1114 5 893   361 17 843   515 5 738
1994 537 4 898   356 18 831   443 5 734
1995 688 10 869   331 18 832   435 7 712
1996 278 8 980   318 19 848   480 5 729
1997 167 5 882   354 18 855   501 3 739
1998 477 6 956   391 16 845   472 3 732
1999 255 4 962   351 18 834   470 7 734
Average 506 8 849   396 17 829   423 6 717
Min 129 4 530   318 14 768   300 2 675
Max 1114 12 980   525 19 855   515 11 739
 
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