Nov 20 (Reuters) - The U.S. Coast Guard announced on Monday that it is actively searching for the source of a significant crude oil leak from an underwater pipeline in the Gulf of Mexico. The estimated volume of the spill has surpassed a million gallons of crude oil, posing a severe threat to the delicate ecosystem in the region.

The leak, which occurred off the Louisiana coast near the Mississippi River Delta, was detected by Main Pass Oil Gathering Co (MPOG) on Thursday morning. Upon discovery, the 67-mile long pipeline was promptly shuttered in an effort to control the spread of the oil.

The Coast Guard deployed overflight teams on Friday, which observed the visible oil moving southwest, away from the Louisiana shore. As recovery operations continue, underwater devices are being utilized to investigate the source of the leak and assess the full extent of the damage.

Although the exact quantity of oil discharged into the Gulf of Mexico remains uncertain, initial engineering estimates conducted by the Coast Guard suggest that over 1.1 million gallons, or 26,190 barrels, have been released thus far.

Recognizing the urgent need for action, the U.S. Environmental Protection Agency (EPA) confirmed on Friday that the Coast Guard had activated the National Response Team. Comprised of 15 federal entities, this team is responsible for coordinating a comprehensive response to oil pollution incidents of such magnitude.

Third Coast Infrastructure, the owner of MPOG, chose not to provide any comments on Friday, instead referring all inquiries to the Coast Guard. The Coast Guard and other federal agencies are currently focused on containment and cleanup operations, aiming to mitigate the environmental impact of the spill as quickly as possible.

The consequences of this significant crude oil leak underscore the importance of pipeline safety and the need for stringent monitoring measures. As investigations continue, the priority remains on identifying the source of the leak and preventing further damage to the Gulf of Mexico's fragile ecosystem.