The recent discovery of a nutria in the Sacramento-San Joaquin Delta in Contra Costa County has raised concerns of damage to the region’s fragile ecosystem from the invasive rodent species, prompting officials to ask the public to report any new sightings. Nutria are native to South America and live in waterways, such as deltas, rivers and ponds. They’re known to be invasive, destroying crops and weakening levees “to the point of failure,” said Matthew Slattengren, an agricultural commissioner for the Contra Costa County Department of Agriculture, on Wednesday. Only a handful of nutria have been spotted in the county in recent years, according to Slattengren and state Fish and Wildlife data. But officials say the animals have the potential to cause “serious damage” to the vast Delta watershed and its network of aging earthen levees — a critical water source for much of California.