Biocomplexity in a highly migratory pelagic marine fish, Atlantic herring.
The existence of biologically differentiated populations has been credited with a major role in conferring sustainability and in buffering overall productivity of anadromous fish population complexes where evidence for spatial structure is uncontroversial. Here, we describe evidence of correlated genetic and life history (spawning season linked to spawning location) differentiation in an abundant and highly migratory pelagic fish, Atlantic herring, Clupea harengus, in the North Sea (NS) and adjacent areas. The existence of genetically and phenotypically diverse stocks in this region despite intense seasonal mixing strongly implicates natal homing in this species. Based on information from genetic markers and otolith morphology, we estimate the proportional contribution by NS, Skagerrak (SKG) and Kattegat and western Baltic (WBS) fish to mixed aggregations targeted by the NS fishery. We use these estimates to identify spatial and temporal differences in life history (migratory behaviour) and habitat use among genetically differentiated migratory populations that mix seasonally. Our study suggests the existence of more complex patterns of intraspecific diversity than was previously recognized. Sustainability may be compromised if such complex patterns are reduced through generalized management (e.g. area closures) that overlooks population differences in spatial use throughout the life cycle.
Ruzzante
Daniel E
DE
Dalhousie University, Department of Biology, Halifax, NS B3H 4J1, Canada. daniel.ruzzante@dal.ca
Mariani
Stefano
S
Bekkevold
Dorte
D
André
Carl
C
Mosegaard
Henrik
H
Clausen
Lotte A W
LA
Dahlgren
Thomas G
TG
Hutchinson
William F
WF
Hatfield
Emma M C
EM
Torstensen
Else
E
Brigham
Jennifer
J
Simmonds
E John
EJ
Laikre
Linda
L
Larsson
Lena C
LC
Stet
René J M
RJ
Ryman
Nils
N
Carvalho
Gary R
GR
D025041:Animal Migration; D000818:Animals; D005260:Female; D005398:Fisheries; D005399:Fishes / Q000235:genetics* / Q000502:physiology; D014644:Genetic Variation; D005843:Geography; D006702:Homing Behavior; D008297:Male; D009659:North Sea; D012621:Seasons; D012726:Sexual Behavior, Animal