Researchers from OSU's Department of Fisheries and Wildlife and the USDA Forest Service determined that a combination of individual fish metabolism, health and rearing temperature, influences the fish's life history. 

Many salmonid fishes are known for the long migrations that they undertake during their lives. Some species, e.g., Oncorhynchus mykiss have populations that either migrate to the ocean (anadromous steelhead) or remain in freshwater (rainbow trout). But what environmental factors help determine and effect whether fish migrate or not? 

Research indicated that changes in somatic growth induced by altered thermal regimes can influence the relationship between body size and the probability of maturation.  Accordingly, somatic growth may not be a robust predictor of shifts in the prevalence of anadromy and residency in partially migratory salmonids when compared across thermal regimes.

Sloat, M., and Reeves, G., 2014.  Individual condition, standard metabolic rate, and rearing temperature influence steelhead and rainbow trout (Oncorhynchus mykiss) life histories.  Canad. J. of Fisheries and Aquat. Sci.  71:491-501.