[CedarDave]

“When this happens, the coastal waters become stratified, meaning that the lighter freshwater will stay at the surface and cap the saltier, and heavier, ocean water beneath,” he explains. “Because the salt water is isolated from the atmosphere, oxygen levels in that water will begin to drop.

A couple of Gulf of Mexico hurricanes will mix it all up.

[smokingfrog]

A couple of smallish tropical storms would be preferable.