VENICE, Italy — The glass blowers of Murano have survived plagues and pandemics. They transitioned to highly prized artistic creations to outrun low-priced competition from Asia. But surging energy prices are shattering their economic model.

The dozens of furnaces that remain on the lagoon island where Venetian rulers transferred glass blowing 700 years ago must burn around the clock, otherwise the costly crucible inside the ovens will break. But the price for the methane that powers the ovens has skyrocketed fivefold on the global market since Oct. 1, meaning the glass blowers face certain losses on orders they are working to fill, at least for the foreseeable future.

“People are desperate,” said Gianni De Checchi, president of Venice’s association of artisans Confartiginato. “If it continues like this, and we don’t find solutions to the sudden and abnormal gas prices, the entire Murano glass sector will be in serious danger.”

A medium-size glass-blowing business like that of Simone Cenedese consumes 420,000 cubic feet of methane a month to keep his seven furnaces hissing at temperatures over 1,800 degrees 24 hours a day. They shut down just once a year for annual maintenance in August.

His monthly bills normally range from 11,000 euros to 13,000 euros a month, on a fixed-price consortium contract that expired Sept. 30. Now exposed to market volatility, Cenedese projects a hike in methane costs to 60,000 euros — or $70,000 — in October, as the natural gas market is buffeted by more Chinese demand, uncertain Russian supply and low European stockpiles.

Artisans like Cenedese now must factor in an insurmountable increase in energy costs as they fill orders that had promised to lift them out of the pandemic crisis that stilled the sector in 2020.

“We cannot increase prices that have already been set. ... That means for at least two months we are forced to work at a loss,” said Cenedese, a third-generation glass blower who took over the business his father started.

His five glass blowers move with unspoken choreographed precision to fill an order of 1,800 Christmas ornaments speckled with golden flakes bound for Switzerland.

One starts the process with a red-hot molten blob on the end of a wand that he rolls over gold leaf, applying it evenly before handing the form to the maestro, who then re-heats it in one oven before gently blowing into the wand to create a perfect orb. It is still glowing red when he cuts it from the wand, and another glass blower grabs it with prongs to add the final flourish, a pointy end created from a dab of molten glass applied by an apprentice.

As that dance progresses, another starts, weaving and bobbing into the empty spaces. Together, they can make 300 ornaments a day.

“No machine can do what we do,” said maestro Davide Cimarosti, 56, who has worked as a glass blower for 42 years.