Half a century of genetic interaction between farmed and wild Atlantic salmon: Status of knowledge and unanswered questions

Abstract

Atlantic salmon (Salmo salar) is one of the best researched fishes, and its aquaculture plays a global role in the blue revolution. However, since the 1970s, tens of millions of farmed salmon have escaped into the wild. We review current knowledge of genetic interactions and identify the unanswered questions. Native salmon populations are typically genetically distinct from each other and potentially locally adapted. Outside Norway, introgression remains unquantified, and in all regions, biological changes and the mechanisms driving population-specific impacts remain poorly documented. Nevertheless, existing knowledge shows that the long-term consequences of introgression is expected to lead to changes in life-history traits, reduced population productivity and decreased resilience to future challenges. Only a major reduction in the number of escapees and/or sterility of farmed salmon can eliminate further impacts. K E Y W O R D Saquaculture, evolution, fish farming, fitness, genetic, hybrid

Population genomics of the introduced and cultivated Pacific kelp Undaria pinnatifida: Marinas—not farms—drive regional connectivity and establishment in natural rocky reefs

“…As such, they are putatively an important source of propagules for the colonization of neighbouring natural habitats (Bulleri & Chapman, 2010; Glasby, Connell, Holloway, & Hewitt, 2007). Similar spillover effects can occur from farmed NIS, as exemplified in the well‐studied Pacific oyster Crassostrea gigas (or Magallana gigas according to the World Register of Marine Species, Costello et al., 2013) in the NE Atlantic (Troost, 2010), or the Atlantic salmon Salmo salar in the NE Pacific (Fisher, Volpe, & Fisher, 2014; Glover et al., 2017). Our working hypothesis is that the sustainable establishment of NIS in natural habitats relies on spillover and/or recurrent propagule pressure (i.e., a source–sink model) from these anthropogenic habitats.…”

Population genetic analysis reveals a geographically limited transition zone between two genetically distinct Atlantic salmon lineages in Norway

“…For the Atlantic salmon (Salmo salar L.), an iconic and economically important anadromous fish that has and continues to be subjected to a diverse array of anthropogenic challenges (Forseth et al, 2017;Glover et al, 2017;Parrish, Behnke, Gephard, McCormick, & Reeves, 1998;Taranger et al, 2015), it has never been more important to map populations, and quantify their evolutionary and contemporary relatedness and connectivity. Given the ever-increasing pressure on much of the world's biota and ecosystems, this is increasingly urgent.…”

Rapid growth causes abnormal vaterite formation in farmed fish otoliths

“…First, as a result of domestication, farmed fish such as Atlantic salmon (Salmo salar L.) now display a range of genetic differences from their wild conspecifics (Glover et al, 2017), so a genetic predisposition to vaterite deformation is possible. While vaterite prevalence in wild-origin fish raised in captivity is high (see fig.…”