Are domesticated freshwater fish an underappreciated culprit of ecosystem change?

In addition to accidental aquaculture escapees, an increasing number of freshwater fish expressing different domestication levels are voluntarily released into the wild primarily as stocking supplement for fisheries and for conservation programmes. Because domestication modifies individual traits and because subtle changes in intraspecific variability can impact ecological dynamics, we argue that these purposeful introductions of domesticated fish may impact the functioning of recipient ecosystems. We posit that purposely introduced domesticated fish could be considered as native invaders and be investigated and managed using frameworks developed for biological invasions. Studies identifying the relative importance of the different ecological mechanisms leading to these ecosystems impacts and quantifying how the intensity of introduction and the level of domestication modulate their ecosystem impacts are needed. This will lead to a better appreciation of how the benefits from releasing domesticated fish are offset by the ecological costs on freshwater ecosystem functioning caused by human-induced local modification of intraspecific diversity patterns.