Tenn. Code § 70-4-121
It is lawful for the director of the United States fish and wildlife service and the director's duly authorized agents to take at any time and in any manner from the public fresh waters of this state all fish required by them for the operation of the state and federal hatcheries. The United States fish and wildlife service is exempt, in the operation of federal fish hatcheries in Tennessee, from the state game laws. The director of the United States fish and wildlife service and the director's duly authorized agents are accorded the right to conduct fish hatching and fish culture and all operations connected with fish hatching and fish culture in any manner and at any time that may by the director be considered necessary and proper, any laws of the state to the contrary notwithstanding.
T.C.A. § 70-4-121