Epigenetics in captivity: Restoring wild phenotypes in captive-reared salmonids

Evolutionary Applications
By: , and 

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Abstract

Captive rearing is a common practice for the stocking, conservation, and supplementation of fish species worldwide, but captive-reared fish can exhibit altered phenotypes leading to reduced fitness in nature compared to wild conspecifics. In salmonids, certain studies have found limited genetic differentiation between wild and captive-reared fish. However, documented changes in gene expression in hatchery fish have led scientists to investigate epigenetic mechanisms, such as DNA methylation, as a source of these differences. In this binational collaborative piece, we synthesize the knowledge and efforts of academics and government scientists to highlight how interactions between captive rearing and the epigenome elicit parallel phenotypic changes across salmonid species. We examine the known and potential links between DNA methylation and the phenotypic effects of captive rearing including changes in behavior, color, gut microbiomes, and developmental abnormalities. We review efforts to minimize these phenotypic and epigenetic effects including attempts to modify the hatchery environment and rearing protocols. We provide a framework to integrate epigenetic considerations into hatchery rearing protocols by weighing the heritable nature of DNA methylation with the goals of different captive rearing programs and explore whether minimizing the phenotypic and epigenetic effects of captive rearing is worthwhile. We examine heritability and persistence of epigenetic effects, and we propose the exploitation of heritable bet-hedging as an epigenetic buffer to increase post-release survival. We also suggest novel applications of epigenomic biomarkers as a non-lethal method for post-release monitoring. Ultimately, collaborative multi-disciplinary research across species is needed to understand the comprehensive effects of captive rearing, reduce the ecological impacts of captive fish in the wild, and increase population resilience. Integrating epigenetics into fish hatchery management will provide new opportunities for optimizing and improving captive rearing.

Suggested Citation

Attfield, T., Honsey, A.E., Ackiss, A.S., Luek, A., Meagher, B., Nuetzel, H., Koch, I., April, J., Wakeling, K., Wellband, K., Bouchard, R., Lehnhert, S.J., Narum, S.R., Healy, T., Pitcher, T.E., and Venney, C.J., 2026, Epigenetics in captivity: Restoring wild phenotypes in captive-reared salmonids: Evolutionary Applications, v. 19, no. 3, e70210, 17 p., https://doi.org/10.1111/eva.70210.

Publication type Article
Publication Subtype Journal Article
Title Epigenetics in captivity: Restoring wild phenotypes in captive-reared salmonids
Series title Evolutionary Applications
DOI 10.1111/eva.70210
Volume 19
Issue 3
Publication Date March 12, 2026
Year Published 2026
Language English
Publisher Wiley
Contributing office(s) Great Lakes Science Center
Description e70210, 17 p.
Additional publication details