Service biologist inspecting a spacer cage

Nathan Eckert, USFWS, inspecting a spacer cage at Genoa National Fish Hatchery (Genoa, WI). The large cage on top is being lifted to reveal the smaller cage below. Juvenile mussels drop off the host and fall into the lower cage where they are physically separated from the fish above and less likely to get swept from the cage. Photo: Ryan Hagerty, USFWS.