NORFOLK, Va. — A bioluminescent algae has been lighting up the lower Chesapeake Bay along the shores of Norfolk and Virginia Beach.

The Virginian-Pilot reported Wednesday that the single-celled organisms form a chain and reproduce in warm water. The algae is present during the day, but becomes most noticeable a couple of hours after sunset.

When waves break, white caps appear bright blue. The turbulence creates a chemical reaction in the algae cells that interacts with the water molecules.

The name of the algae is Alexandrium monilatum. And it can be harmful to fish and oysters. Scientists say that it’s possible that some of the algae broke off of a bloom in the York River and flowed south.