Amplify Energy shares tumbled more than 35% in premarket trading

Amplify Energy shares tumbled more than 35% in premarket trading.

A large oil spill off the southern California coast left fish dead, birds mired in petroleum and wetlands contaminated, in what local officials called an environmental catastrophe.

The U.S. Coast Guard, heading a clean-up response involving federal, state and city agencies, on Sunday announced an around-the-clock investigation into how the spill occurred.

An estimated 126,000 gallons, or 3,000 barrels, had spread into an oil slick covering about 13 square miles of the Pacific Ocean since it was first reported on Saturday morning, Kim Carr, the mayor of Huntington Beach, told a news conference.

She called the spill an "environmental catastrophe" and a "potential ecological disaster". The beachside city, about 40 miles (65 km) south of Los Angeles, was bearing the brunt of the spill.

The spill was caused by a breach connected to the Elly oil rig and stretched from the Huntington Beach Pier down to Newport Beach, an area popular with surfers and sunbathers.

Carr said the oil rig was operated by Beta Offshore, a California subsidiary of Houston-based Amplify Energy Corporation(AMPY.N). Calls to Beta and Amplify went unanswered.

Martyn Willsher, CEO of Amplify Energy, says the pipeline has been shut off and any remaining oil in it had been suctioned off, preventing further releases.

But not before an estimated 126K gallons of oil had been spilled, spoiling beaches and threatening wetlands south of Los Angeles.