Designing a Stocking Program to Learn More about Population Dynamics

Fish stocking programs are initiated to augment fisheries or to help restore depleted populations.  Subsequent monitoring is often done to evaluate the success of stocking efforts in terms of the program’s goals, usually by surveying fishing success or by examining survival, growth, and migration of stocked fish.  Although less commonly done, stocking programs could be designed not only to augment wild stocks, but also to answer specific questions or test hypotheses about life history, population dynamics, habitat requirements, or the effectiveness of management initiatives aimed at improving the wild population.  Because stocking can result in a large number of marked individuals, the timing and locations of releases and subsequent recaptures of stocked fish can be designed to provide valuable information.  We will discuss how data from stocking and sampling known-aged, marked individuals at various locations can be used to estimate wild population size; to learn about growth, survival, and behavior in different habitats; to validate ageing methods; and to evaluate possible outcomes and issues associated with other management initiatives, such as passage at dams.  Specific examples will include a restoration program that involves stocking of American shad adults and fry in the Roanoke River, North Carolina.  By designing the release and subsequent monitoring of stocked fish with specific questions in mind, a stocking program can not only increase the size of a population, but can also provide additional information to aid in its successful management.