Rapid adaptation to a new environment: is it reversible?

• Main Author: Araki, Hitoshi
• Other Authors: Romana-Eguia, Maria Rowena R., Parado-Estepa, Fe D., Salayo, Nerissa D., Lebata-Ramos, Ma. Junemie Hazel
• Format: Conference Object
• Language: English
• Published: Aquaculture Department, Southeast Asian Fisheries Development Center 2015
• Subjects: Salmo trutta; Oncorhynchus gorbuscha; Oncorhynchus mykiss; Salmonidae; Oncorhynchus tshawytscha; Oncorhynchus kisutch; Fish stocking; Rapid adaptation; Reproductive fitness; Salmonid species; Hatcheries; Adaptations; Breeding; Anadromous species; Behaviour; Stocks; Culture effects; Reproduction; Reproductive behaviour; Cultured organisms; Fish culture
• Online Access: http://hdl.handle.net/10862/2760

Accumulating evidence suggests rapid adaptation of fish populations when they are exposed to artificial hatchery environments. However, little is known if rapidly-adapted populations can readapt to their original, natural environment at the same rate. Here, I review recent studies on salmonid fish that address this issue. They indeed suggest rapid adaptation of hatchery populations, in which reproductive fitness under a natural environment became much lower than that in the wild population after only 1-2 generations of captive breeding. However, the reproductive fitness did not recover after one generation of natural rearing, implying that rapid adaptation to a new environment was not reversible at the same rate. I discuss potential consequences of the irreversible fitness reduction in extensively stocked fish species. Understanding the mechanism behind the irreversible rapid adaptation in fish populations will help us figure out a better, nature-friendly, and hence sustainable means of hatchery operations for human welfare.