Petition to List Lynn Canal Pacific Herring under the Endangered ...

William Sound may indicate that the populations are so large that same-sized
alleles arise in the populations by different evolutionary pathways, making the
collections appear undifferentiated. The extreme haplotype diversity in these
herring (Paul Bentzen, preliminary summary to WDFW, March 13, 2004) would
support a hypothesis of large effective population sizes. Alternatively, or in
addition, interannual variability may be so high in AK herring stocks that at times
they are genetically undifferentiated simply by chance. In another puzzling
comparison, the AK stocks were undifferentiated from Port Gamble and
Northumberland herring. This may have been a result of poor genetic
characterization of the 02Port Gamble stock, but this fails to account for
relationships with 99Port Gamble and 99Northumberland. Pairwise genotypic
tests are highly sensitive and detect even subtle differences among subpopulations
(Balloux and Lugon-Moulin 2002). Thus, the lack of differentiation is puzzling.
(Small et al. 2004).
D. Comparison with Atlantic Herring
McPherson et al. (2004) determined that population structure in Atlantic Herring
exists at the basin, shelf, and bank scales, and demonstrated interannual stability, as
reflected by allele frequency homogeneity and analyses of molecular variance.
In summary, we have provided evidence for genetic differentiation among
spawning groups of Atlantic herring at a number of spatial scales. Replicate
samples and year-class analyses, when used to test for the annual temporal
stability of allele frequencies at four locations, show stability in the majority of
cases. When these results are interpreted within the context of the retention and
metapopulation models proposed for herring, we find that neither model is fully
consistent with our observations.
(McPherson et al. 2004).
Similarly, Jorgensen et al. (2005) determined that Atlantic Herring within the
Baltic Sea are separated into several genetically distinct populations that correlate mainly
with environmental variables.
Based on our results we clearly reject the hypothesis that herring in the Baltic Sea
constitutes one panmictic unit. Previous studies employing allozyme and
mitochondrial DNA markers have found significant differentiation among herring
populations inhabiting relatively closed marine areas such as fjords (e.g. Jörstad et
al. 1991; Turan et al. 1998), whereas no significant genetic differentiation was
found between herring populations from open sea areas, including the Baltic Sea
(e.g. Ryman et al. 1984; Turan et al. 1998). More recently, studies employing
microsatellite DNA markers have revealed statistically significant albeit low
differentiation among spawning groups from open marine areas (e.g. Shaw et al.
1999; McPherson et al. 2004), and our results are in accordance with these
VII