Sussex Police said an unexploded shell was found at an industrial site this morning (March 7).
A police spokesperson said: "Shortly before 7am on Thursday (March 7) an unexploded shell was reported to have been found on industrial premises in Basin Road South, Portslade-by-Sea.
"It is believed it had been hauled up from the seabed by a dredger.
"A military Explosive Ordnance Disposal unit was sent to deal with the weapon by means of a controlled explosion.
"No evacuation was necessary."