Crews recovered about 500 gallons of fuel oil apparently leaking from a sunken tugboat after a sheen was spotted near an offshore mooring buoy off Barbers Point and another was reported about 7 miles south of Hono­lulu Airport.

The 95-foot towing vessel sank Thursday near Barbers Point with 75,000 gallons of diesel still in its hull.

An oil sheen was observed by the Coast Guard before nightfall after the towboat Nalani got into trouble about 2.5 miles west of Barbers Point Harbor. The Nalani sank in some 2,200 feet of water.

Coast Guard crews are searching the ocean and beaches from Barbers Point to Nana­kuli for signs of oil and wildlife affected by a diesel oil spill.

A Clean Islands Council vessel observed a sheen estimated at 1 mile long and 50 feet wide near the offshore mooring buoy off Barbers Point.

The fishing vessel Seahawk also reported a red diesel sheen about 7 miles south of Hono­lulu Airport. A Clean Islands Council vessel was responding to that scene Friday, according to a news release.

The Coast Guard set up a command center Friday on Sand Island.

Additional overflights of the area are scheduled for Saturday.

The Coast Guard said shorelines don’t appear to be affected by diesel, although the smell of diesel has been reported at White Plains and Nana­kuli. Air sampling did not produce levels of concern, the Coast Guard said.

A National Oceanic and Atmospheric Administration patrol boat rescued nine crew members and the towboat Tiger 7 rescued two after the Nalani sank. No injuries were reported.

A Coast Guard vessel took the crew of the sunken tugboat to Hono­lulu. All 11 survivors were wearing life ­­jackets.

The Coast Guard is conducting an investigation into the sinking incident.

Officials are asking the public to report signs of oil on beaches or in the water to the Coast Guard Sector Hono­lulu Command Center at 842-2600.