The Wall Street Journal and several other sources are reporting that the Coast Guard is investigating a 100-mile sheen of a substance that may be oil floating on the surface of the Gulf of Mexico. Reports began to come in on Saturday morning of a rainbow slick that began off the coast of Grand Isle, Louisiana and extended far out to sea.

Crews have been have been sent to the area to assess the situation, which is unfolding about twenty miles from the site of the Deepwater Horizon, the well that exploded last April and set in motion a disastrous chain of events whose full impact has yet to be measured. A report from Business Insider released after 10:00pm EDT on Saturday indicated that the well involved might be the Matterhorn Seastar, but other sources state that it is too early to connect the spill to any specific drilling site.

This could be the first spill event to make use of money from the Oil Spill Liability Trust Fund, which was established in response to the Deepwater Horizon incident. The fund collects oil company profits to be dispersed for cleanup costs in the event of another oil spill disaster.