No one has yet identified the source of the waste and there were no reports of injuries. State environmental officials are investigating the incident.
A stretch of coastline along Normandy Beach in Ocean County was closed, and beaches were closed in Toms River.
But on a bright and sunny Labor Day, all lifeguarded ocean beaches were open.
The New Jersey Department of Environmental Protection said all Ocean County beaches that were closed Sunday afternoon due to trash washing up on the beach were reopened Monday morning.
Monday's regular coastal surveillance flight from Raritan Bay south to Barnegat Light found beach and water conditions to be 'good.'
Crews from the Toms River Department of Public Works hit the beach at dawn and cleaned up all debris.
Speaking at a Labor Day parade in South Plainfield, Governor Jon Corzine said, 'We actually think it is a garbage spill, as opposed to medical waste. The first issue is protect the public.'