Population genetic substructure in blue whiting based on allozyme data

Abstract

The genetic population structure of the pelagic gadoid blue whiting Micromesistius poutassou throughout its east Atlantic distribution range was explored using polymorphisms at the tissue enzyme loci IDHP-2* and PGM-1*. The study included 5025 individuals from 65 locations in the east Atlantic and the Mediterranean. Significant geographic heterogeneity in allele frequencies was demonstrated at both loci (IDHP-2*: P=0·030, PGM-1*: P=0·005). The degree of genetic differentiation (F ST =1·1%) in blue whiting appears to be at the same level as for the demersal gadoids cod and haddock. Several separate reproductive units were indicated at the fringes of the distribution range, i.e. in the Barents Sea, and in one Norwegian fjord (Romsdalsfjord). 1998 The Fisheries Society of the British Isles

Genetic differentiation of blue whiting (Micromesistius poutassou Risso) populations at the extremes of the species range and at the Hebrides–Porcupine Bank spawning grounds

“…These mini-and microsatellite data are compatible with results from allozyme studies on blue whiting (Giaever and Stien, 1998), in that the strongest differentiation is found for populations at the extremes of the species range, a pattern also seen in Atlantic cod Gadus morhua L. (Mork et al, 1985). While allozyme analysis has shown significant differentiation of the Barents Sea blue whiting sample, statistically significant differentiation of the Mediterranean blue whiting population was not reported by Giaever and Stien (1998).…”

“…While allozyme analysis has shown significant differentiation of the Barents Sea blue whiting sample, statistically significant differentiation of the Mediterranean blue whiting population was not reported by Giaever and Stien (1998).…”

“…Temporal population differentiation in blue whiting has previously been observed in allozyme frequencies in the Barents Sea (Giaever and Stien, 1998), where samples taken from 1992 and 1995 were genetically distinct.…”

“…Allele frequencies at two loci (IDHP-2* and PGM-1*) from 65 samples in the East Atlantic and Mediterranean revealed significant geographic heterogeneity and pointed to a genetically distinct population in the Barents Sea, with potentially isolated populations (not statistically significant) in the Mediterranean and Romsdalsfjord, Norway (Giaever and Stien, 1998). There was also evidence of temporal differentiation among some Barents Sea samples taken in 1992 and 1995.…”

“…First, to explore the overall level and pattern of genetic differentiation in Northeast Atlantic and Mediterranean blue whiting by means of a newly developed set of DNA mini-and microsatellite markers (Rico et al, 1997;Moran et al, 1999;Mattiangeli et al, 2002;Ryan et al, 2002), and to compare the picture obtained with that revealed by former allozyme studies (Mork and Giaever, 1995;Giaever and Stien, 1998). The second aim of the study was to use these new DNA markers to explore the genetic relationships among blue whiting spawning samples from the Porcupine Bank and Hebridean Shelf during the annual spawning aggregation.…”