MEPS 247:303-309 (2003)  -  doi:10.3354/meps247303

Genetically different Atlantic herring Clupea harengus spawning waves

Arran A. McPherson1,3,*, Robert L. Stephenson2, Christopher T. Taggart1

1Department of Oceanography, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada
2St. Andrews Biological Station, Department of Fisheries and Oceans, 531 Brandy Cove Road, St. Andrews, New Brunswick E5B 2L9, Canada
3Present address: Bedford Institute of Oceanography, Department of Fisheries and Oceans, 1 Challenger Drive, Dartmouth, Nova Scotia B2Y 4A2, Canada

ABSTRACT: Putative spawning waves of Atlantic herring Clupea harengus were collected from 4 locations and genetically compared using 9 microsatellite loci. Shelf-scale (100s km) spatial differences were measured (max FST = 0.01, p < 0.001) and 1 sub-annual temporal difference (FST = 0.0058, p = 0.001) was revealed between spawning fish (predominantly comprising the same year-class) collected, 6 d apart, from the same location (Devastation Shoal, coastal Nova Scotia). Herring in the second spawning collection at Devastation Shoal had a greater average length-at-age within the year-class (t-test, p < 0.001). The genetic and morphometric differences between the Devastation Shoal collections are assumed to reflect a replacement period of spawning fish of approximately 6 d or less (at least at this location). We offer 3 explanations to account for the observations: (1) genetically distinct sympatric subpopulations or spawning waves; (2) sub-annual (d) genetic patchiness; and (3) transient use of spawning grounds which may indicate that the assumption of philopatry (natal spawning-site fidelity) in herring is invalid.

KEY WORDS: Spawning wave · Atlantic herring · Sympatric populations · Genetic

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