TY - JOUR
T1 - Winning the invasion roulette: escapes from fish farms increase admixture and facilitate establishment of non-native rainbow trout
AU - Consuegra, Sonia
AU - Phillips, Nia
AU - Gajardo, Gonzalo
AU - Garcia de Leaniz, Carlos
N1 - Online early
PY - 2011/5/24
Y1 - 2011/5/24
N2 - Aquaculture is a major source of invasive aquatic species, despite the fact that cultured organisms often have low genetic diversity and tend to be maladapted to survive in the wild. Yet, to what extent aquaculture escapees become established by means of high propagule pressure and multiple origins is not clear. We analysed the genetic diversity of 15 established populations and four farmed stocks of non-native rainbow trout in Chile, a species first introduced for recreational fishing around 1900, but which has in recent decades escaped in large numbers from fish farms and become widespread. Aquaculture propagule pressure was a good predictor of the incidence of farm escapees, which represented 16% of all free-ranging rainbow trout and were present in 80% of the study rivers. Hybrids between farm escapes and established trout were present in all rivers at frequencies ranging between 7 and 69%, and population admixture was positively correlated with genetic diversity. We suggest that non-native salmonids introduced into the Southern Hemisphere could benefit from admixture because local adaptations may not have yet developed, and there may be initially little fitness loss resulting from outbreeding depression.
AB - Aquaculture is a major source of invasive aquatic species, despite the fact that cultured organisms often have low genetic diversity and tend to be maladapted to survive in the wild. Yet, to what extent aquaculture escapees become established by means of high propagule pressure and multiple origins is not clear. We analysed the genetic diversity of 15 established populations and four farmed stocks of non-native rainbow trout in Chile, a species first introduced for recreational fishing around 1900, but which has in recent decades escaped in large numbers from fish farms and become widespread. Aquaculture propagule pressure was a good predictor of the incidence of farm escapees, which represented 16% of all free-ranging rainbow trout and were present in 80% of the study rivers. Hybrids between farm escapes and established trout were present in all rivers at frequencies ranging between 7 and 69%, and population admixture was positively correlated with genetic diversity. We suggest that non-native salmonids introduced into the Southern Hemisphere could benefit from admixture because local adaptations may not have yet developed, and there may be initially little fitness loss resulting from outbreeding depression.
KW - aquaculture
KW - gene flow
KW - genetic admixture
KW - invasion
KW - Oncorhynchus mykiss
KW - propagule pressure
UR - http://hdl.handle.net/2160/8050
U2 - 10.1111/j.1752-4571.2011.00189.x
DO - 10.1111/j.1752-4571.2011.00189.x
M3 - Article
C2 - 25568013
SN - 1752-4571
VL - 4
SP - 660
EP - 671
JO - Evolutionary Applications
JF - Evolutionary Applications
IS - 5
ER -