Fine-scale population genetic structure in Alaskan Pacific halibut (Hippoglossus stenolepis)

Abstract

Pacific halibut collected in the Aleutian Islands, Bering Sea and Gulf of Alaska were used to test the hypothesis of genetic panmixia for this species in Alaskan marine waters. Nine microsatellite loci and sequence data from the mitochondrial (mtDNA) control region were analyzed. Eighteen unique mtDNA haplotypes were found with no evidence of geographic population structure. Using nine microsatellite loci, significant heterogeneity was detected between Aleutian Island Pacific halibut and fish from the other two regions (F ST range = 0.007-0.008). Significant F ST values represent the first genetic evidence of divergent groups of halibut in the central and western Aleutian Archipelago. No significant genetic differences were found between Pacific halibut in the Gulf of Alaska and the Bering Sea leading to questions about factors contributing to separation of Aleutian halibut. Previous studies have reported Aleutian oceanographic conditions at deep inter-island passes leading to ecological discontinuity and unique community structure east and west of Aleutian passes. Aleutian Pacific halibut genetic structure may result from oceanographic transport mechanisms acting as partial barriers to gene flow with fish from other Alaskan waters.

Low levels of global genetic differentiation and population expansion in the deep-sea teleost Hoplostethus atlanticus revealed by mitochondrial DNA sequences

“…This pattern of high haplotype diversity is common in marine fishes and consistent with previous reports for cyt b sequences in orange roughy by Baker et al (1995) and in the bluemouth Helicolenus dactylopterus by Aboim et al (2005). Similarly, high values of diversity have been reported for mtDNA d-loop sequences in other deep-sea fishes such as the thornyhead rockfishes Sebastolobus alascanus, S. altivelis, and S. macrochir, the cape hake Merluccius capensis, the Alaskan Pacific halibut Hippoglossus stenolepis, and the alfonsino Beryx decadactylus (Stepien et al 2000;von der Heyden et al 2007;Nielsen et al 2010;Friess and Sedberry 2011). The lack of genetic differentiation among orange roughy populations from the South Atlantic Ocean and South Pacific Ocean is surprising given the large geographic distances between the regions surveyed in this study.…”

Dispersal and behavior of Pacific halibut Hippoglossus stenolepis in the Bering Sea and Aleutian Islands region

“…Using a variety of nuclear micro satellite loci, statistically significant (p < 0.10) permutation test results suggest that segregation occurs between halibut collected near Adak Island and those collected near both St. Paul Island and the US Pacific Northwest (Hauser et al 2006). In an other study, significant (p < 0.05) heterogeneity was detected between halibut from the Aleutian Islands and those from the GOA and the SEBS (F ST range: 0.007 to 0.008; Nielsen et al 2010). Significant F ST values represent the first genetic evidence of divergent groups of Pacific halibut in the central and western Aleutian Archipelago.…”

“…Early genetic evidence (Grant et al 1984, Bentzen et al 1999 was consistent with the hypothesis of panmixia, but recent work suggests mixing of some stock components (Hauser et al 2006, Nielsen et al 2010. Accordingly, population dynamics in the SEBS, Aleutian Islands, and GOA have appeared somewhat decoupled from one another over the last decade.…”

“…al 2006, Nielsen et al 2010. Using a variety of nuclear micro satellite loci, statistically significant (p < 0.10) permutation test results suggest that segregation occurs between halibut collected near Adak Island and those collected near both St. Paul Island and the US Pacific Northwest (Hauser et al 2006).…”

Incorporation of bomb-produced14C into fish otoliths. An example of basin-specific rates from the North Pacific Ocean

“…The results validated the B&B methodology, at least for the GOA and southward to central British Columbia. However, there is demographic (Hare 2006), genetic (Hauser et al 2006;Nielsen et al 2010), and behavioral (Loher and Clark 2010;Seitz et al 2011) evidence that suggests a degree of stock structure in the eastern Pacific halibut population, wherein important stock parameters may differ among the GOA, EBS, and Aleutian Islands region. The western GOA and the EBS, even though adjacent geographically, represent largely unique water bodies with respect to both hydrographic and biotic structure resulting in subtle but different otolith growth patterns (Forsberg 2001).…”