Most of Lake Tashmoo reopened for shellfish harvesting Thursday morning at daybreak, with a small area still closed in the aftermath of a diesel oil spill last week.

“Most of the pond there is no problem,” said Greg Sawyer, an aquatic biologist with the state Division of Marine Fisheries (DMF) who surveyed the shoreline Tuesday along with two biologists from his office, and Tisbury shellfish constable Danielle Ewart. “But along the shoreline, especially north of the Lake Street ramp, it got into the sediment,” he added. “You could still smell the fuel in the air and in the sand and the peat.”

About 20 per cent of the pond remains closed. The entire pond was closed to shellfishing on March 30, after a the 33-foot sport fishing boat Snooper sank on its mooring. U.S. Coast Guard and Massachusetts Department of Environmental Protection (DEP) personnel estimated less than 20 gallons of diesel fuel spilled from the vessel’s fuel tank, creating a sheen of diesel fuel over a wide area of the pond on both sides of the Lake street dock and boat ramp.

The area that remains closed is from about 700 feet south of Flat Point to the northern end of Brown’s Point, Mr. Sawyer said. DMF ordered the area to be posted with signs warning local commercial and recreational shellfishermen of the closure.

DMF will survey the area again next week, to see if any remaining fuel has evaporated.

“With the sunshine over the weekend and next week, it’s not going to take long to get rid of it,” Mr. Sawyer said. “Hopefully by the end of next week, everything will be open.”

The Coast Guard issued Ronald Barry, the owner of the sunken vessel a letter of warning, but no fine.

“If anything happens in the future, it would be a $50 fine, if it’s less than 50 gallons,” said Mark Dewein, a marine safety technician with the Coast Guard’s Marine Safety Detachment on Cape Cod. “He’s basically using up his free pass.”