The invasive pest spotlight focuses on emerging or potential invasive pests in California. In this issue we are covering nutria. The nutria is a large semi-aquatic rodent introduced to California in the early 1900s to be farmed for their fur. … Nutria have since spread into waterways within the Sacramento-San Joaquin River Delta and the Central Valley. … Nutria severely damage the environment, roads, levees, and crops. They burrow into banks of waterways, weakening or collapsing them. As they feed, they damage the native plant communities and soil structure of wetlands. Nutria feeding and burrowing damage both increase the risk of erosion and flooding.