title: Fishing amplifies forage fish population collapses.
abstract: Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches.
authors.affiliation: School of Aquatic and Fishery Sciences and essing@uw.edu.
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Essington
authors.affiliation: School of Aquatic and Fishery Sciences and.
authors.forename: Pamela E
authors.initials: PE
authors.lastname: Moriarty
authors.affiliation: School of Aquatic and Fishery Sciences and.
authors.forename: Halley E
authors.initials: HE
authors.lastname: Froehlich
authors.affiliation: School of Aquatic and Fishery Sciences and.
authors.forename: Emma E
authors.initials: EE
authors.lastname: Hodgson
authors.affiliation: School of Aquatic and Fishery Sciences and.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Koehn
authors.affiliation: Quantitative Ecology and Resource Management, University of Washington, Seattle, WA 98195.
authors.forename: Kiva L
authors.initials: KL
authors.lastname: Oken
authors.affiliation: School of Aquatic and Fishery Sciences and.
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Siple
authors.affiliation: Quantitative Ecology and Resource Management, University of Washington, Seattle, WA 98195.
authors.forename: Christine C
authors.initials: CC
authors.lastname: Stawitz
mesh_terms: D000818:Animals; D018533:Biomass; D003247:Conservation of Natural Resources; D017753:Ecosystem; D005398:Fisheries; D005399:Fishes / Q000502:physiology; D020387:Food Chain; D008954:Models, Biological; D011157:Population Dynamics
keywords: ecosystem-based management; fisheries; marine conservation; population collapse
references.citation: Science. 1993 Apr 2;260(5104):17-36
references.pmid: 17793516
references.citation: Ecol Appl. ;24(6):1543-57
references.pmid: 29160672
references.citation: Ecol Lett. 2011 Dec;14(12):1288-99
references.pmid: 21985428
references.citation: Nature. 2010 Jun 3;465(7298):609-12
references.pmid: 20520713
references.citation: Proc Natl Acad Sci U S A. 2013 Aug 13;110(33):13672-7
references.pmid: 23836661
references.citation: Science. 2011 Dec 23;334(6063):1703-6
references.pmid: 22194577
references.citation: Proc Natl Acad Sci U S A. 2009 Aug 25;106(34):14722-7
references.pmid: 19706557
references.citation: Science. 2003 Jan 10;299(5604):217-21
references.pmid: 12522241
references.citation: Science. 2011 Aug 26;333(6046):1147-50
references.pmid: 21778363