51813_Sturgeon biodioversity an.PDF

a

b

Figure 3.UPGMAphenograms of the interpopulationdiversity indices for the (a)RFLPdata, and(b) controlregionsequencedata for
Acipenseroxyrinchusfrom theGulf of Mexico.

northern populations that recolonized glaciated
drainages from more genotypically diverse popula-
tions in southern, nonglaciated regions.

than one stock. For management purposes, it is im-

portant to quantitatively estimate the relative con-

tributions of individual stocks to mixed fisheries to

allow managers to protect threatened stocks at sites

distant from their natal rivers. Successful applica-

tion of genetic approaches to mixed-stock analysis

is dependent on the existence of significant differ-

entiation of genetic characters among spawning

stocks which contribute to the mixed fishery (Utter

& Ryman 1993, Xu et al. 1994). Toconduct mixed

Mixed-stockanalysis

For somewiderangingspecies, fisherieshavedevel-
opeddistantfrom spawningandnursery areas, and
thesefisheries mayharvestindividualsfrommore