The Oak Bluffs harbor is closed to shellfishing until further notice following a minor oil spill Wednesday morning.

A 50-foot tuna-fishing boat has taken on water, causing leach of oil into the harbor, town officials said.

After receiving a call around 7:50 a.m. Wednesday morning reporting a fuel smell and a sheen on the water, shellfish constable David Grunden notified the fire department, which dispatched their oil recovery team to the boat tied up at Church’s Pier, by Nancy’s Restaurant.

It appears the cause of the leak was a faulty shaft seal, fire officials said. Once the boat takes on water, the bilge is programmed to pump excess water out of the boat to keep it afloat. This water was contaminated with motor oil, said acting fire chief John Rose. He said the spill is not major and will probably amount to between eight and 12 gallons of oil.

“The estimates are under what would be considered a real hazardous spill,” Mr. Rose said. “There should be very little, if any, impact on the environment.”

The harbor will be closed to shellfishing activity for a minimum of 72 hours. Mr. Grunden will work with the state Division of Marine Fisheries to take water samples and analyze the hydrocarbon content, which indicates the presence of fuel.

The oil spill is contained in a small area in the corner of the harbor, due to fortunate wind and tide patterns, Mr. Grunden said. “We are extremely lucky,” he said.

The leaking boat is now protected by a cushion boom, which stops the flow of oil, and the fire department has also deployed absorption pads and sock booms to contain and ameliorate the spill. The absorption pads and sock booms will be removed by the end of the day today, Mr. Grunden said. The security boom around the boat will stay until the leak is corrected.

Clean Harbors Inc. will perform the cleaning. The Coast Guard also were on the scene to assess the spill Wednesday morning.
The harbor is only open to shellfishing during the winter months, where shellfishermen harvest quahaugs and steamers, Mr. Grunden said.