Emigration probabilities and survival estimates of stocked juvenile lake sturgeon (Acipenser fulvescens) within the Genesee River, NY

Knowledge of juvenile lake sturgeon (Acipenser fulvescens) survival is important both to understanding changes in population abundance and for assessing the efficacy of management practices like stocking. High mortality rates of juvenile fish are partially mitigated by stocking hatchery-raised individuals; however, survival of post-stocked lake sturgeon remains lower compared to survival at older life stages. In this study, acoustic telemetry data from 69 age-0+ (weight: $\overline{x}$ = 29 g, range = 2–41 g; length: $\overline{x}$ = 198 mm, range = 176–223 mm) and 30 sub-adults (weight: $\overline{x}$ = 2144 g, range = 1100–7020 g; length: $\overline{x}$ = 751 mm, range = 605–1020 mm) tagged in the fall of 2019 and 2020 were utilized to construct a multi-state model used to estimate both survival and spatial transitions between the Genesee River and Lake Ontario. Sub-adults (approximate ages: 4–7 years) had estimated survival rates exceeding 88 % in both the Genesee River and Lake Ontario. Age-0+ lake sturgeon displayed much lower survival rates that ranged between 31 % (Lake Ontario) and 77 % (Genesee River). Both age-0+ and sub-adults lake sturgeon were most likely to leave the Genesee River in the fall and winter months, while being most likely to return in the spring and summer months. The approach used in this study to estimate survival is hypothesized to have led to higher survival estimates than traditional Capture-Mark-Recapture (CMR) derived estimates as a result of accounting for emigration from the Genesee River.