A 30-foot sport fishing boat that sank overnight Monday in Lake Tashmoo was removed from the pond Tuesday, as officials continued to assess damage from the diesel fuel that spilled into the water.

Reached by phone Tuesday afternoon, Department of Environmental Protection spokesman Joe Ferson said the boat had been lifted out of the water without any additional leakage.

Snooper being pulled from the water; officials said most of the fuel stayed on board. — Timothy Johnson

Shellfish beds remained closed, but the overall environmental impacts of the spill fortunately were minimal, Mr. Ferson said. Oil that escaped produced a thin sheen that floated visibly on the lake's surface, but most of the vessel's 150 gallons were still on board. Rainbow patterns were also evident along the shoreline at the Lake street landing.

"It looks as if it's a minimal impact due to the fact that the vent holes were plugged immediately and during the removal process," Mr. Ferson said.

Ronald Barry of Falmouth, the boat owner, is responsible for recovery and clean-up costs, Mr. Ferson said. The costs of the response have yet to be determined.

By early Monday afternoon, fire department personnel had mostly contained the diesel oil that spilled from the sunken boat, the Snooper out of Boston. On Tuesday estimates from the Coast Guard, who were on the scene, put the amount of the spill at about 20 gallons. Tisbury shellfish constable Danielle Ewart was walking the shoreline to assess possible damage.

Ms. Ewart notified the Massachusetts Division of Marine Fisheries (DMF) about the spill Monday morning, and state officials ordered the pond closed to shellfishing until further notice. DMF officials reportedly traveled to the Island to assess the damage. Ms. Ewart said she responded to the spill and notified the harbor master at 8:43 a.m.

Oil soaking pads were spread along the shoreline. — Timothy Johnson

A sheen of diesel oil spread over a large portion of the Lake Tashmoo shoreline on both sides of the Lake street boat landing, an area where many shellfish beds are located.

Tisbury fire chief John Schilling estimated there was about 150 gallons of diesel fuel on board when the vessel sank. At first it was not immedately known how much fuel had spilled into the pond.

“There’s no more fuel coming out of the boat,” said Chief Schilling just before noon on Monday. “Our goal is to contain it and keep it from spreading any further.”

The sport fishing boat, about 30 feet long, lay on its port side in shallow water near the head of Lake Tashmoo, about 300 yards south of the Lake street dock. Only part of the cabin and the fly bridge remained above water.

The odor of diesel fuel hung in the air as local fishermen deployed an emergency containment boom along the dock to catch some of the spreading fuel sheen. The boom was stored on the scene for such an emergency.

The Coast Guard said less than 20 gallons of diesel fuel spilled into the water. — Timothy Johnson

Tisbury officials responded with their oil spill prevention and response unit later to deploy a much larger oil containment boom along the shoreline. First responders also spread oil soaking pads along the shoreline, which quickly blotted up pink-dyed diesel fuel.

Diesel fuel is lighter than saltwater, and when spilled, most of it floats on the surface where it quickly evaporates. But fuel additives can sink and contaminate the bottom, and fuel which settles on the shoreline can contaminate sand and soil. Fire officials said they were concerned that the rising tide would push some of the fuel further up the shoreline, leaving contamination when the tide recedes.