The environment experienced by a fish during its early hatchery life can profoundly affect its survival later in the wild. This is because individuals differ in key life history traits such as growth rate, which may increase or decrease their survival later in life. These traits can also be amplified by the environment, with consequences for entire populations. Understanding how an individual’s early life affects long-term performance (‘carryover effects’) is particularly relevant for fish stocking, as millions of fish that have potentially variable growth are stocked into rivers and impoundments annually. While quantifying the effectiveness of fish stocking may be difficult, it is vitally important information for fisheries managers. This project addresses a fundamental gap in our understanding of what drives fish survival and subsequent stocking success, by exploring whether early life growth has lasting impacts on individual fitness in the wild. I will quantify the growth of individual fish that occurred in hatcheries prior to stocking into a range of impoundments, and then see how this influences the probability of survival after 6 months and 1 year. My results will provide critical information for managers to optimise hatchery practices to stock the fish with the highest chance of survival.