Stable isotope analysis challenges wasp-waist food web assumptions in an upwelling pelagic ecosystem

Sci Rep. 2012:2:654. doi: 10.1038/srep00654. Epub 2012 Sep 13.

Abstract

Eastern boundary currents are often described as 'wasp-waist' ecosystems in which one or few mid-level forage species support a high diversity of larger predators that are highly susceptible to fluctuations in prey biomass. The assumption of wasp-waist control has not been empirically tested in all such ecosystems. This study used stable isotope analysis to test the hypothesis of wasp-waist control in the southern California Current large marine ecosystem (CCLME). We analyzed prey and predator tissue for δ¹³C and δ¹⁵N and used Bayesian mixing models to provide estimates of CCLME trophic dynamics from 2007-2010. Our results show high omnivory, planktivory by some predators, and a higher degree of trophic connectivity than that suggested by the wasp-waist model. Based on this study period, wasp-waist models oversimplify trophic dynamics within the CCLME and potentially other upwelling, pelagic ecosystems. Higher trophic connectivity in the CCLME likely increases ecosystem stability and resilience to perturbations.

MeSH terms

  • Animals
  • Aquatic Organisms / metabolism*
  • Bayes Theorem
  • Biodiversity*
  • California
  • Carbon Isotopes / metabolism
  • Cluster Analysis
  • Diet
  • Ecosystem
  • Food Chain*
  • Models, Biological
  • Nitrogen Isotopes / metabolism
  • Oceans and Seas

Substances

  • Carbon Isotopes
  • Nitrogen Isotopes