title: Culling prey promotes predator recovery--alternative states in a whole-lake experiment.
abstract: Many top-predator fish stocks in both freshwater and marine systems have collapsed as a result of overharvesting. Consequently, some of these communities have shifted into seemingly irreversible new states. We showed, for predators feeding on prey that exhibit food-dependent growth, that culling of fish prey may promote predator recovery. We removed old stunted individuals of a prey-fish species in a large, low-productive lake, which caused an increase in the availability of small-sized prey and allowed the predator to recover. The shift in community state has been sustained for more than 15 years after the cull ended and represents an experimental demonstration of an alternative stable state in a large-scale field system. Because most animals exhibit food-dependent growth, shifts into alternative stable states resulting from overcompensating prey growth may be common in nature and may require counterintuitive management strategies.
authors.affiliation: Department of Ecology and Environmental Science, Umeå University, S-901 87 Umeå, Sweden. lennart.persson@emg.umu.se
authors.forename: Lennart
authors.initials: L
authors.lastname: Persson
authors.forename: Per-Arne
authors.initials: PA
authors.lastname: Amundsen
authors.forename: André M
authors.initials: AM
authors.lastname: De Roos
authors.forename: Anders
authors.initials: A
authors.lastname: Klemetsen
authors.forename: Rune
authors.initials: R
authors.lastname: Knudsen
authors.forename: Raul
authors.initials: R
authors.lastname: Primicerio
mesh_terms: D000818:Animals; D049628:Body Size; D017753:Ecosystem; D005399:Fishes / Q000502:physiology*; D020387:Food Chain; D005618:Fresh Water; D009664:Norway; D011157:Population Dynamics; D011235:Predatory Behavior; D012474:Salmon / Q000502:physiology; D014337:Trout / Q000502:physiology