title: Large scale, synchronous variability of marine fish populations driven by commercial exploitation.
abstract: Synchronous variations in the abundance of geographically distinct marine fish populations are known to occur across spatial scales on the order of 1,000 km and greater. The prevailing assumption is that this large-scale coherent variability is a response to coupled atmosphere-ocean dynamics, commonly represented by climate indexes, such as the Atlantic Multidecadal Oscillation and North Atlantic Oscillation. On the other hand, it has been suggested that exploitation might contribute to this coherent variability. This possibility has been generally ignored or dismissed on the grounds that exploitation is unlikely to operate synchronously at such large spatial scales. Our analysis of adult fishing mortality and spawning stock biomass of 22 North Atlantic cod (Gadus morhua) stocks revealed that both the temporal and spatial scales in fishing mortality and spawning stock biomass were equivalent to those of the climate drivers. From these results, we conclude that greater consideration must be given to the potential of exploitation as a driving force behind broad, coherent variability of heavily exploited fish species.
authors.affiliation: Ocean and Ecosystem Sciences Division, Bedford Institute of Oceanography, Dartmouth, NS, Canada B2Y 4A2; Department of Biology, Queen's University, Kingston, ON, Canada K7L 3N6 kenneth.frank@dfo-mpo.gc.ca.
authors.forename: Kenneth T
authors.initials: KT
authors.lastname: Frank
authors.affiliation: Ocean and Ecosystem Sciences Division, Bedford Institute of Oceanography, Dartmouth, NS, Canada B2Y 4A2;
authors.forename: Brian
authors.initials: B
authors.lastname: Petrie
authors.affiliation: Department of Biology, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: William C
authors.initials: WC
authors.lastname: Leggett
authors.affiliation: Department of Biology, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Boyce
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D018533:Biomass; D057231:Climate Change; D003132:Commerce; D005398:Fisheries; D048389:Gadus morhua; D009026:Mortality; D011157:Population Dynamics
keywords: climate forcing; cod; fishing mortality; synchrony