Commercial deliveries of diesel fuel to fishermen working from the Lake street dock on Lake Tashmoo have been stopped, after operating for some 18 months, apparently illegally.

The action followed a report to town selectmen on Tuesday night by the Tashmoo management and harbor management committees, which not only deemed the operation an environmental hazard, but also took the selectmen to task for “selective and preferential enforcement” of regulations prohibiting commercial activity on the dock.

In a sharply worded statement to the board, Melinda Loberg, the Tashmoo committee chairman, chided them for having asked Tisbury’s harbor master not to enforce the regulations prohibiting the refueling activity.

“The committees ask, why not enforce the regulations first, as is your duty as our elected officials, and then work to change them if that’s your goal?” Ms. Loberg said.

“Selective and preferential enforcement does not inspire confidence that you can be counted on to equally enforce regulations in other areas of town government.”

She said permission to refuel at the Lake street dock gave special privileges to three or four commercial fishermen, and the damage from a spill from the refueling truck, operated by Island Fuel, or from one of the boats being refueled was potentially disastrous.

Already the health of the lake is challenged by poor tidal flushing and a depletion of eelgrass, Ms. Loberg said.

The town has made a major investment in the Tashmoo fishery through dredging, shellfish seeding and restorations of the herring run to help fishermen, and would likely have to spend more to remediate its poor water circulation and nitrogen-enrichment problems, she said.

“Why would the town want to introduce a hazard that could jeopardize all this effort?” Ms. Loberg asked.

She noted the selectmen had asked the committee to come up with recommendations that would allow refueling activity to continue, but regulated as to times, days of the week and to consider charging a fee to the vendor.

“Both the Tashmoo and harbor management committees respectfully disagree,” she said. “This activity should not be permitted in Lake Tashmoo.”

There were 280 mooring holders in Tashmoo and 612 shellfishing permits issued this year, almost the entire perimeter of the lake is residential property, and any fuel spill would impact them all. The few fishermen involved could refuel elsewhere, as in Oak Bluffs or Falmouth.

“Gentlemen,” Ms. Loberg concluded, “this decision should be a no-brainer.”

But the evidence before the selectmen showed a more complex conflict, not related solely to the commercial supply of fuel and the environment.

Indeed, as the fuel supplier, as well as Tisbury fire chief John Schilling, fishermen and others explained, at a previous canvassing of the matter in August, the use of the fuel truck probably reduced the threat of environmental damage.

The supplier carried insurance, the trucks were licensed by the state fire marshal, carried absorbent material and a boom kit, and their drivers were screened and trained. The alternative to allowing the fuel truck was that fishermen would use other, more risky means to refuel their boats, carrying fuel down the dock in cans.

And in the August discussion, Ms. Loberg alluded to wider concerns. She said there had been disagreements about use of the dock, that people trying to launch or recover boats, shellfishermen, kayakers and the general public were having access problems because fishermen dominated the use of the dock.

Those concerns, however, were not mentioned in the report on Tuesday night, although one selectman, Jeff Kristal, did refer to “an underlying issue of bullying,” as well as abuse of dockage space and the removal of signs.

Mr. Schilling again asserted his belief that, when compared with the other 300-odd recreational users of the lake, the truck refueling of the fishing boats was the “safest operation that takes place on Lake Tashmoo.”

But his expert opinion in the end counted for not much, and a moratorium was put in place on the fuel operation.

That is not necessarily the end of the matter, though.

Commercial fisherman Glenn Pachico suggested as a compromise that the selectmen consider allowing fuel sales at the Owen Park dock, and yesterday Jay McMann, of Island Fuel, said he was exploring other options.

Among those is an application to the town for a permit to allow the service to begin again at Lake street.

Geoghan Coogan noted the board must balance competing interests, and he said commercial fishermen were struggling to keep their livelihoods. He said, however, the selectmen should require a formal application for any commercial activity.

In other business, selectmen discussed the operation of the town shellfish department, following the death of shellfish constable Derek Cimeno last month.

As an interim measure, they asked the harbor master Jay Wilbur to manage operations on the water while administrative secretary Hillary Conklin handles the department’s administrative work.

In the longer term, they are considering amalgamating the shellfish and harbor master departments.

They also propose to name the herring run at the head of Tashmoo after Mr. Cimeno.