Mixed stock analysis and the power of different classes of molecular markers in discriminating coastal and oceanic Atlantic cod (Gadus morhua L.) on the Lofoten spawning grounds, Northern Norway

Wennevik, Vidar; Jørstad, Knut Eirik; Dahle, Geir; Fevolden, Svein-Erik

doi:10.1007/s10750-008-9349-5

Cited by 33 publications

(20 citation statements)

References 77 publications

(100 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 and Table 1). Samples representing stationary ecotypes, named 'coastal cod' or 'stationary cod' in Iceland and 'Norwegian coastal cod' in Norway, and migratory ecotypes, named 'frontal cod' or 'migratory cod' in Iceland and 'Northeast Arctic cod' in Norway, were collected from spawning grounds from Iceland and Norway, and individuals were assigned to ecotype based on sampling location and depth (Iceland) and ear bone (otolith) morphology [Norway, see also Wennevik et al (2008)]. In Iceland, samples were collected in inshore waters (depth: 58 m), known to be mainly inhabited by the stationary ecotype, and from a deeper offshore location (depth: 135 m), where the migratory ecotype has been suggested to predominate (Pampoulie et al 2006(Pampoulie et al , 2008a.…”

Section: Samplingmentioning

confidence: 99%

“…Individuals displaying an intermediate type of behaviour have been identified through electronic tagging of fish in the wild (Grabowski et al 2011), suggesting that hybridization may occur in nature, but the degree of interbreeding and level of gene flow between ecotypes is presently unknown. Traditionally, morphological characters, such as ear bone (otolith) structures, and single gene markers, such as the membrane protein gene pantophysin (Pan I), have been used to designate individuals as either migratory or stationary (Berg & Albert 2003;Pampoulie et al 2008a;Wennevik et al 2008). Recently, population genetic work has provided some molecular evidence for adaptive divergence between the ecotypes from Norway (Moen et al 2008;Nielsen et al 2009b), and the finding of consistent migratory profiles over consecutive years for individual fish has suggested a genetic basis for ecotypic divergence in Iceland (Thorsteinsson et al 2012).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A genomic island linked to ecotype divergence in Atlantic cod

et al. 2013

View full text Add to dashboard Cite

The genomic architecture underlying ecological divergence and ecological speciation with gene flow is still largely unknown for most organisms. One central question is whether divergence is genome-wide or localized in 'genomic mosaics' during early stages when gene flow is still pronounced. Empirical work has so far been limited, and the relative impacts of gene flow and natural selection on genomic patterns have not been fully explored. Here, we use ecotypes of Atlantic cod to investigate genomic patterns of diversity and population differentiation in a natural system characterized by high gene flow and large effective population sizes, properties which theoretically could restrict divergence in local genomic regions. We identify a genomic region of strong population differentiation, extending over approximately 20 cM, between pairs of migratory and stationary ecotypes examined at two different localities. Furthermore, the region is characterized by markedly reduced levels of genetic diversity in migratory ecotype samples. The results highlight the genomic region, or 'genomic island', as potentially associated with ecological divergence and suggest the involvement of a selective sweep. Finally, we also confirm earlier findings of localized genomic differentiation in three other linkage groups associated with divergence among eastern Atlantic populations. Thus, although the underlying mechanisms are still unknown, the results suggest that 'genomic mosaics' of differentiation may even be found under high levels of gene flow and that marine fishes may provide insightful model systems for studying and identifying initial targets of selection during ecological divergence.

show abstract

Section: Samplingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A genomic island linked to ecotype divergence in Atlantic cod

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Although assessed separately, the NCC is managed as part of the Norwegian NEAC fishery. A large part of the Norwegian cod fishery is targeting the spawning components of the NEAC during spring (Nakken et al 1996), which results in catches of mixed stocks (Wennevik et al 2008). The management takes this into account by adding an expected yield of 20 000 tons of NCC to the TAC of the NEAC.…”

Section: Codmentioning

confidence: 99%

“…For marine species the relative proportion of different cod populations mixing in overwintering areas in the NW Atlantic was estimated by Ruzzante et al (2000a). Here not only the proportion of the various cod populations could be estimated but also the temporal stability of this structuring was demonstrated over a 2-year period (see also Ruzzante et al 2006;Bekkevold et al 2007;Wennevik et al 2008). Therefore, it seems possible that fisheries management could be designed around the spatial and temporal population structure within the separated spawning grounds and the areas where populations are mixed (Ruzzante et al 2000a;ICES, 2005c).…”

Section: Spatial Mismatch -Implications For Fisheries Managementmentioning

confidence: 99%

Genetic population structure of marine fish: mismatch between biological and fisheries management units

et al. 2009

View full text Add to dashboard Cite

Introduction 362Determination of populations and management units 363 Mismatch between management and biological units in the NE Atlantic 371Fisheries management and management units in the NE Atlantic 371Population structure of demersal fish species 372Cod 372Haddock 378Other demersal roundfish species 378Plaice 379Sole 379Other flatfish species 380 AbstractAn essential prerequisite of a sustainable fisheries management is the matching of biologically relevant processes and management action. In fisheries management and assessment, fish stocks are the fundamental biological unit, but the reasoning for the operational management unit is often indistinct and mismatches between the biology and the management action frequently occur. Despite the plethora of population genetic data on marine fishes, to date little or no use is made of the information, despite the fact that the detection of genetic differentiation may indicate reproductively distinct populations. Here, we discuss key aspects of genetic population differentiation in the context of their importance for fisheries management. Furthermore, we evaluate the population structure of all 32 managed marine fish species in the north-east Atlantic and relate this structure to current management units and practice. Although a large number of studies on genetic population structure have been published in the last decades, data are still rare for most exploited species. The mismatch between genetic population structure and the current management units found for six species (Gadus morhua, Melanogrammus aeglefinus, Merlangius merlangus, Micromesistius poutassou, Merluccius merluccius and Clupea harengus), emphasizes the need for a revision of these units and questions the appropriateness of current management measures. The implementation of complex and dynamic population structures into novel and less static management procedures should be a primary task for future fisheries management approaches.

show abstract

“…The classification or assignment of individuals from potential mixed stocks to their population of origin remains a challenge in fisheries management, although both individual assignment (e.g., the STRUCTURE approach) and mixedstocks analysis (e.g., BAYES) have been intensively used in this context Wennevik et al 2008). The challenge comes from the fact that both methods crucially depend on the number of baseline populations (i.e., populations potentially contributing to the mixed aggregations), the number of individuals sampled from each of them, the variability and number of loci used, and ultimately the level and temporal stability of the genetic differentiation among the baseline populations.…”

Section: Discussionmentioning

confidence: 99%

The composition of adult overwintering and juvenile aggregations of Atlantic cod (Gadus morhua) around Iceland using neutral and functional markers: a statistical challenge

Pampoulie

Ruzzante

2012

Can. J. Fish. Aquat. Sci.

View full text Add to dashboard Cite

The collapse of marine fisheries worldwide has forced recognition of the fact that sustainable fisheries management cannot be achieved without a reasonable understanding of stock structure. Fisheries focusing on species that exhibit seasonal migrations between spawning and feeding grounds should consider the composition of feeding aggregations of presumed mixed origin. Using nine microsatellites and the Pan I locus, we assess the contribution of two previously described major spawning components of Icelandic cod Gadus morhua (southwest and northeast) to two large feeding and two large juvenile aggregations of presumed mixed origin and situated in the northwest and northeast of Iceland. The Bayesian approaches (STRUCTURE and BAYES) revealed that, with the exception of the juvenile samples collected in 2002 and 2003 in the northeast, most of the individuals originated from the southwest. These results confirmed that the Icelandic cod exhibit a complex biological pattern involving spawning site fidelity and migration to and from feeding aggregations. The sustainable management of the Icelandic cod is likely to be compromised if its complex dynamics is not properly integrated into fisheries management plans.Résumé : L'effondrement des pêches marines à travers le monde oblige à reconnaître que la gestion durable de la pêche ne peut être atteinte sans une compréhension raisonnable de la structure des stocks exploités. Les pêches exploitant les espèces qui font des migrations saisonnières entre les aires de ponte et les aires de nourrissage communes doivent également tenir compte de la composition de ces rassemblements de nourrissage présumés d'origine mixte. Utilisant neuf microsatellites et le locus Pan I, nous avons évalué la contribution des deux principales sous-populations de la morue islandaise Gadus morhua précédemment décrites (sud-ouest et nord-est de l'Islande) aux deux grands rassemblements alimentaires et aux deux rassemblements de juvéniles, d'origine mixte présumée, et situés dans le nord-ouest et nord-est du pays. Les deux approches bayésiennes utilisées (STRUCTURE et BAYES) révèlent que, à l'exception des échantillons de juvéniles collectés en 2002 et en 2003 dans le nord-est, la plupart des individus semblent provenir de la population du sud-ouest. Ces résultats confirment que la morue islandaise présente un modèle biologique complexe impliquant la fidélité au site de ponte et une migration aller-retour vers les rassemblements de nourrissage. Par conséquent, la gestion durable de la morue d'Islande est susceptible d'être compromise si cette dynamique complexe n'est pas correctement intégrée dans les plans de gestion des pêches.

show abstract

Mixed stock analysis and the power of different classes of molecular markers in discriminating coastal and oceanic Atlantic cod (Gadus morhua L.) on the Lofoten spawning grounds, Northern Norway

Cited by 33 publications

References 77 publications

A genomic island linked to ecotype divergence in Atlantic cod

A genomic island linked to ecotype divergence in Atlantic cod

Genetic population structure of marine fish: mismatch between biological and fisheries management units

The composition of adult overwintering and juvenile aggregations of Atlantic cod (Gadus morhua) around Iceland using neutral and functional markers: a statistical challenge

Contact Info

Product

Resources

About