Give them a huge oil blowout, and they can use up enough oxygen to create anoxic "dead zones" that imperil fish and other sea creatures.

The water would exert less pressure on the oil and gas down below, which is why it was important that 【concrete seals】 were in place to avoid any blowout.

If the rate is at the low end of the range and was lower still before a key pipe on top of the blowout preventer was cut to accommodate the top hat, about half as much oil has been spilled so far.