Universal power-law diet partitioning by marine fish and squid with surprising stability–diversity implications

Axel Rossberg, Keith Farnsworth, K. Satoh, J.K. Pinnegar

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


A central question in community ecology is how the number of trophic links relates to community species richness. For simple dynamical food-web models, link density (the ratio of links to species) is bounded from above as the number of species increases; but empirical data suggest that it increases without bounds. We found a new empirical upper bound on link density in large marine communities with emphasis on fish and squid, using novel methods that avoid known sources of bias in traditional approaches. Bounds are expressed in terms of the diet-partitioning function (DPF): the average number of resources contributing more than a fraction f to a consumer's diet, as a function of f. All observed DPF follow a functional form closely related to a power law, with power-law exponents indepen- dent of species richness at the measurement accuracy. Results imply universal upper bounds on link density across the oceans. However, the inherently scale-free nature of power-law diet partitioning suggests that the DPF itself is a better defined characterization of network structure than link density.
Original languageEnglish
Pages (from-to)1617-1625
Number of pages9
JournalProceedings of the Royal Society of London. Series B, Biological Sciences
Issue number1712
Early online date10 Nov 2010
Publication statusPublished - 07 Jun 2011

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Environmental Science(all)
  • Immunology and Microbiology(all)
  • Medicine(all)


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