The James River has been closed to shellfish harvesting down to the vicinity of the Monitor Merrimac Bridge Tunnel because of flooding that resulted from heavy rain in the western part of Virginia.

Runoff from the recent western-Virginia storms may have washed animal waste and human sewage into the River, according to an announcement Tuesday by the Virginia Department of Health. The agency also announced a similar closure of a portion of the Rappahannock River.

Shellfish taken from the affected portions of those rivers could cause gastrointestinal illnesses and have been declared unacceptable for consumption, the agency announced.

“We watch shellfish beds for contaminants after major storms to ensure any seafood harvested there does not contain harmful substances that will make consumers of these shellfish ill,” Virginia State Health Commissioner Karen Remley said. “The closed areas will be reopened as soon as test results indicate that they are safe to reopen.”

The affected shellfish are bivalve mollusks, including oysters and clams, but not crabs or fin fish.