Before we stage a release, we evaluate the wild population to establish a reference for any potential impact our release might have. Our goal is to enhance wild populations—not to support the growth of more fish than naturally can be supported by the local environment. To date, we have not detected any measurable negative impact of our stock enhancement research on wild populations of winter flounder. These populations have remained stable since we began to sample them in 2003.

To evaluate whether our cultured fish are displacing the wild population, we monitor wild juvenile winter flounder through sampling and acoustic tracking. We estimate the abundance of wild winter flounder in the estuary, their size distribution, and the spatial use of the estuary by different sizes of flounder. Growth, movements, habitat use, and diet of wild fish are compared to that of cultured fish. In the future we plan to use acoustic tracking technology to track mature flounder when they return to estuaries to spawn.