Attributes / relations provided by
♦ ¹Food of Northwest Atlantic Fishes and Two Common Species of Squid, Ray E. Bowman, Charles E. Stillwell, William L. Michaels, and Marvin D. Grosslein, NOAA Technical Memorandum NMFS-NE-155 (2000)
♦ ²The harbour seal Phoca vitulina as a predator in the Skagerrak. Haerkoenen, T | Heide-Joergensen, M-P, Ophelia. Vol. 34, no. 3, pp. 191-207 1991