Capt. Peter Gautier says the Coast Guard is investigating about 90 pollution cases in the wake of Hurricane Isaac.
They include six minor leaks and oil sheens from sources such as tank batteries and wellheads. Such leaks are expected after hurricanes, he says.
Gautier says oil found on about eight birds at Myrtle Grove came from storage tanks at a closed terminal.
In Braithwaite, chemicals leaked into water and air from tanks at a storage facility, but all are under control, he says.
Gautier says some railroad tank cars containing hazardous chemicals overturned during the storm but are secure. Isaac also grounded three deep-draft ships, he says, but the vessels are not leaking.