Credit: USFWS   Japanese Knotweed

One of the biggest threats to refuge habitat conservation often appears as healthy, lush vegetation. Plants like Japanese knotweed invade about 30% of refuge lands, taking over with agressive growth that crowds out native species. The refuge is challenged by the difficult task of controlling invasive plants so that habitats like bottomland hardwood forests can be restored.

Refuge wildlife is also affected by invaders. Zebra mussels are a serious threat to native mussels. These Caspian Sea natives entered the Ohio River in the early 1990s, probably through barge and boat traffic. They attach to hard objects, including native mussels. Huge numbers of zebra mussels often cover the shells of native species, competing with them for food filtered from the water. This stress sometimes brings the starvation of native mussels.

Learn More - FWS Invasive Species Page

Credit: USFWS Zebra Mussels Encrusting Native Mussels