Analysis of coastal cod (Gadus morhua L.) sampled on spawning sites reveals a genetic gradient throughout Norway’s coastline

• Main Authors: Dahle, Geir, Quintela, María, Johansen, Torild, Jon-Ivar Westgaard, Besnier, François, Asgeir Aglen, Jørstad, Knut, Glover, Kevin
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Figshare 2018
• Subjects: Genetics; FOS Biological sciences; 59999 Environmental Sciences not elsewhere classified; FOS Earth and related environmental sciences; Ecology; 69999 Biological Sciences not elsewhere classified; Marine Biology; Inorganic Chemistry; FOS Chemical sciences; Arctic; Norway; Arctic cod; atlantic cod; Gadus morhua; North Atlantic
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.4159208; https://figshare.com/collections/Analysis_of_coastal_cod_Gadus_morhua_L_sampled_on_spawning_sites_reveals_a_genetic_gradient_throughout_Norway_s_coastline/4159208

Abstract Background Atlantic cod (Gadus morhua L.) has formed the basis of many economically significant fisheries in the North Atlantic, and is one of the best studied marine fishes, but a legacy of overexploitation has depleted populations and collapsed fisheries in several regions. Previous studies have identified considerable population genetic structure for Atlantic cod. However, within Norway, which is the country with the largest remaining catch in the Atlantic, the population genetic structure of coastal cod (NCC) along the entire coastline has not yet been investigated. We sampled > 4000 cod from 55 spawning sites. All fish were genotyped with 6 microsatellite markers and Pan I (Dataset 1). A sub-set of the samples (1295 fish from 17 locations) were also genotyped with an additional 9 microsatellites (Dataset 2). Otoliths were read in order to exclude North East Arctic Cod (NEAC) from the analyses, as and where appropriate. Results We found no difference in genetic diversity, measured as number of alleles, allelic richness, heterozygosity nor effective population sizes, in the north-south gradient. In both data sets, weak but significant population genetic structure was revealed (Dataset 1: global FST = 0.008, P