A marine scientist says underwater oil plumes are reducing oxygen in parts of the Gulf of Mexico, but the drop-off isn’t steep enough to endanger marine life just yet.

Samantha Joye of the University of Georgia said Tuesday that water samples show oxygen concentrations within the plumes are dropping 1 to 2 percent each day.

She said at that rate, it would take months for levels to become hazardous for fish and other animals.

Vast amounts of methane are leaking from the ruptured Deepwater Horizon oil well. Microbes feeding on the methane also consume oxygen.

Scientists say if that process goes too far, it could create “dead zones” with so little oxygen that virtually nothing could live.