The fate of farmed rainbow trout (Oncorhynchus mykiss) released from commercial aquaculture operations in Lake Huron

Abstract

The fate of farmed fish after escape is poorly understood. The extent to which these fish might impact freshwater ecosystems is dependent upon their survival and distribution in the wild. I simulated small- and large-scale escape events from two commercial aquaculture operations in Lake Huron over 2 years. I combined the use of telemetry (120) and Floy (1000) tags to determine the fate of escaped farmed rainbow trout (Oncorhynchus mykiss). Once released, escapees dispersed rapidly, showed low site fidelity (~15% after 3 months) and were capable of long distance movements (up to 360 km). Rainbow trout experienced low survival (~50%) but maintained high growth rates both at and away from the farms. The results of this study provide a strong basis for understanding the potential risks that farmed fish may pose to the Lake Huron fish community and ecosystem in an escape event.