HUNTINGTON BEACH, Calif. — An oil sheen spotted off the Southern California coast last week was possibly caused by a natural seep from the ocean floor, but the exact source still isn’t known, U.S. Coast Guard officials said Monday.
Authorities detected the 2.5-mile-long (4-kilometer-long) oil sheen Friday morning off Huntington Beach. Crews recovered roughly 85 gallons (322 liters) of oil from the water and 1,050 pounds (476 kilos) of oily waste and tar balls from the shoreline, the Coast Guard said in a statement.
Lab tests so far have failed to definitively identify the oil source, but preliminary analyses determined it was not a refined product like gasoline or diesel, officials said.
“The lab results were also inconsistent with archived samples from oil platforms in the area,” the statement said. The samples are more characteristic of “freshly produced” oil typical of natural seepage, according to officials.
Authorities said initially that there were no reports of spills or leaks from oil platforms operating offshore and the sheen did not appear to be growing, which led them to suspect it was a one-time discharge of oil from the ocean floor, which are fairly common.
By the time responders conducted flights over the area Saturday, they could no longer see any recoverable sheen. There were some clumps of tar along the beach but not enough to warrant a weekend closure, and there did not appear to be any public health threat, officials said.
The Coast Guard said three live birds — a cormorant, a loon and a grebe — were found sullied with oil and were being treated.
A 2021 leak in an offshore pipeline sent blobs of crude oil washing ashore in Huntington Beach, a surf-friendly city about 30 miles (48 kilometers) southeast of Los Angeles.
The United States Coast Guard recently announced that an oil sheen spotted off the coast of California is likely the result of natural seepage from the ocean floor, rather than a man-made oil spill. The sheen was first reported by a commercial fishing vessel approximately 3 miles off the coast of Huntington Beach, prompting an investigation by the Coast Guard.
After conducting aerial surveillance and deploying a pollution response team to the area, the Coast Guard determined that the oil sheen was most likely caused by natural seepage from the ocean floor. This phenomenon is not uncommon in the waters off the coast of California, as the region is known for its abundant oil and gas reserves.
Natural oil seeps occur when underground reservoirs of oil and gas are under pressure, causing them to leak through cracks in the Earth’s crust and rise to the surface of the ocean. These seeps can release small amounts of oil and gas into the water over time, creating sheens that are often mistaken for man-made oil spills.
While natural seepage is a natural and ongoing process in marine environments, it can still have environmental impacts. Oil sheens can harm marine life, disrupt ecosystems, and pose a risk to human health if they come into contact with coastal communities. In response to the oil sheen off the coast of California, the Coast Guard has been monitoring the situation closely and working with local authorities to assess any potential risks.
It is important for the public to be aware of the difference between natural oil seeps and man-made oil spills, as well as the potential environmental consequences of both. By understanding the sources of oil in our oceans and taking steps to mitigate their impacts, we can help protect marine ecosystems and ensure the health and safety of coastal communities.
