In the annals of thankless jobs on the Vineyard, the Oak Bluffs Firemen’s Civic Association’s effort to organize the annual fireworks display — a staple of summer on the Vineyard for over three decades — ranks right up there with moped dealer and traffic cop.

The civic association raises the money, organizes the event and cleans up afterwards; a job that requires much time and effort. People turn out by the thousands each year to watch the spectacular display — scheduled for tonight over Ocean Park around 9 p.m. — and they are not required to pay for the show.

Instead, buckets are handed around during the fireworks and people are asked to make donations. Until recently the buckets were stuffed with bills from thankful spectators. But that giving spirit has taken a dramatic turn for the worse in recent years, and people are no longer reaching into their wallets to say thank you to the firemen with their donations.

Ken Davey, head of the association’s fireworks committee, said waning financial support and volunteer involvement has placed the annual mid-August event in jeopardy. And although his warnings are now a familiar refrain, Mr. Davey told Gazette this week the 2008 fireworks display may be the civic association’s last.

“If I had to guess, I would say this is our last one. The whole reason we do this is to make money, and we aren’t making money anymore. It’s that simple. People seem to take the fireworks for granted; they think the fireworks will be there every year no matter what. But we can’t lose money just to put them on,” Mr. Davey said.

Mr. Davey said the main source of revenue for the association, T-shirt sales, are about half what they used to be. Sales of the T-shirts were basically nonexistent until a few weeks ago, and not nearly enough has been raised to cover the $20,000 needed for the fireworks each year.

Mr. Davey said the event has not been flush for a number of years, but this year is worse than ever. Business donations are off, although it is unclear whether that stems from a slower summer on the Vineyard, a sluggish national economy or something entirely different. A lack of interest has also forced the association to cancel a fund-raising cruise for people willing to pay a little extra to watch the fireworks from the sea.

All in all, people are being a little less generous this summer, he said.

“Who knows how much people will give [during] the fireworks. We are hoping for the best, but planning for the worse,” Mr. Davey said.

And while the fireworks will go on as planned, Mr. Davey said the association could be lacking in its other charitable endeavors — which much like the fireworks often go unheralded or recognized.

Each year, the money raised after expenses goes to charitable works for year-round Islanders, including scholarships for students at the Martha’s Vineyard Regional High School, food baskets for needy families at Christmas, and in previous years a Christmas party for children at the Portuguese-American Club. The association has also provided aid to injured town employees and firefighters, and is the sponsor for the town cub scout and boy scout troops.

Mr. Davey said there is a widely-held misconception that the money raised before and during the fireworks goes directly to the fire department, not the firemen’s civic association.

“And that’s a big difference . . . people think this money is being used to buy a new [fire] truck or new equipment, when in reality it is being used to help an Island student pay for college or make sure someone has a meal around the holidays. That’s what’s frustrating,” he said.

To make matters worse, the association has had to come up with additional money in recent years to fund necessary changes during the display. The association had to purchase approximately 1,000 feet of barricades, new trailers and additional signs.

And then of course there are the gripes from spectators about the quality of the show.

“If the sky is cloudy or the weather bad, we hear people complaining the show wasn’t good . . . as if that’s our fault,” Mr. Davey said. “We want to put on a good show and we want people to enjoy themselves . . . but it isn’t as easy as people think. And it gets harder each year.”