After Hurricane Ida’s 240kph winds wreaked havoc on offshore oil production platforms and onshore oil and gas processing plants, the US Coast Guard announced on Monday that it was investigating nearly 350 complaints of oil spills in and along the US Gulf of Mexico.

The Coast Guard has been flying over the Louisiana coast in search of oil spills. It is informing federal, state, and local officials in charge of cleaning up the locations. On Sunday, flights discovered signs of a new leak from an offshore well, as well as confirmation that another, responsible for a kilometre-long streak of oil, had been contained.

After the storm made landfall on August 29, about 88% of the region’s offshore oil production was shut down, and more than 100 platforms were left vacant.

Offshore oil producer Talos Energy, which hired divers and a clean-up crew to respond to an oil spill in Bay Marchand, said old pipelines damaged during the storm were responsible. It also noted that the spill off the coast of Port Fourchon, Louisiana, had decreased substantially since it was first discovered last week.

According to Coast Guard spokesman, Lt John Edwards, the source of the Bay Marchand leak remains unknown. “[A Coast Guard-led team] will be looking at all potential sources in order to ensure any future risk is mitigated.”

The Louisiana Department of Environmental Quality is also collaborating with the Coast Guard and the United States Environmental Protection Agency to order companies liable for spills to halt production and clean up the mess.

The Department said: “If necessary USCG and/or the EPA can open federal funding streams to cover mitigation costs.”

The Environmental Agency said: “EPA has received 39 reports relative to the hurricane in our area of responsibility and has been evaluating those reports and following up with responsible parties to ensure they are being addressed.”