title: Stable isotope analysis challenges wasp-waist food web assumptions in an upwelling pelagic ecosystem.
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.
authors.affiliation: Tuna Research and Conservation Center of Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA. dmadigan@stanford.edu
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Madigan
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Carlisle
authors.forename: Heidi
authors.initials: H
authors.lastname: Dewar
authors.forename: Owyn E
authors.initials: OE
authors.lastname: Snodgrass
authors.forename: Steven Y
authors.initials: SY
authors.lastname: Litvin
authors.forename: Fiorenza
authors.initials: F
authors.lastname: Micheli
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Block
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000378:metabolism*; D001499:Bayes Theorem; D044822:Biodiversity; D002140:California; D002247:Carbon Isotopes / Q000378:metabolism; D016000:Cluster Analysis; D004032:Diet; D017753:Ecosystem; D020387:Food Chain; D008954:Models, Biological; D009587:Nitrogen Isotopes / Q000378:metabolism; D009792:Oceans and Seas
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes