Nonprofits that feed hundreds of hungry Islanders every week are facing unprecedented reductions in supplies of groceries, at a time when the need is growing.

Starting earlier this year, staffing shortages at the Greater Boston Food Bank have been cutting into the amount of free produce and low-cost staples available to the Island Food Pantry and other Vineyard charities such as Good Shepherd Parish.

“It’s got nothing to do with the ability to get food. It’s a labor issue,” said Joe Capobianco of Good Shepherd, speaking with the Gazette by phone Monday from aboard a Steamship Authority ferry on his way back from picking up a 3,000-pound order from the Boston food bank.

A normal Monday pickup for Good Shepherd was 4,000 to 6,000 pounds, Mr. Capobianco said, until the cutbacks began to bite.

“We lost 500 pounds. Then we lost another 500 pounds,” he said. “It steadily got worse.”

A third 500-pound cut to each of the parish’s two weekly orders has left Good Shepherd short a total of 3,000 pounds of food a week for its Tuesday and Saturday distributions, he said.

The food shortages were a main topic for discussion at a meeting last Thursday of the Island food equity network — an informal coalition of social service agencies and volunteers. The meetimg was held at the Agricultural Hall.

The number of Island households seeking food relief continues to rise, network members said.

Last Tuesday, Mr. Capobianco said, Good Shepherd saw 61 visitors representing more than 250 household members. The parish also hands out 140 boxes of food on Saturdays.

The Island Food Pantry, now a program of Island Grown Initiative, is serving more than double the number of people it did two years ago, IGI executive director Rebecca Haag told the Gazette.

About 1,100 to 1,200 Islanders are using the pantry every month, said Ms. Haag, who noted a particularly sharp increase in the number of children receiving food.

Based on family registrations, she said, the pantry has gone from serving 178 children in February 2019 to 454 in February of this year.

Many of them are from households with working parents, Ms. Haag said.

“They work in low-wage jobs and very seasonal jobs: the landscapers, the construction workers, the fishermen, the house cleaners, the cooks at the restaurants [and] the people who work in the cafeterias at schools,” she said. “They work very hard, but they can’t make ends meet.”

Other working families may need temporary food assistance due to a crisis, such as illness or injury, Ms. Haag said.

“They don’t have a lot of savings, and if something goes wrong they need our help,” she said.

As summer nears, Ms. Haag said, the food pantry is seeing new registrations from seasonal workers, recently arrived, whose earnings don’t yet match their gas, shelter and food costs.

“They need transitional help,” she said. “Once they get settled in, they’ll probably be fine.”

Elderly Islanders, whose fixed incomes are vulnerable to inflation, and people who are homeless also need the pantry to get by, Ms. Haag said.

Taken together, the food pantry’s clientele is a cross-section of the Island’s diversity, she said.

“They’re probably the parents of some kids your kids play with, or they’re your dental assistant or your landcaper,” Ms. Haag said. “They’re not faceless people.”

To keep up with the demand, IGI has been supplementing its food bank orders with products from wholesale restaurant supplier Sysco, which charges significantly more.

“We always have food available, but our food costs are just astronomical right now,” said Merrick Carreiro, IGI’s senior director of food equity programs, speaking at the meeting last week.

Ms. Haag said IGI is projected to exceed its $450,000 annual food budget by $300,000 this year.

“We’re going to have to raise more money,” she told the Gazette.

Island Grown also needs to find more sources of food, Ms. Haag said, as the Greater Boston Food Bank’s staffing shortages show no sign of abating. The food bank’s website lists a dozen open positions, from warehouse hands to big-rig drivers.

Mr. Capobianco said the shortages have forced him to limit what Good Shepherd can provide to each household. Clients dropping by for food on Tuesdays can no longer bring their own — sometimes Ikea-sized — shopping bags, he said: Good Shepherd has purchased reusable grocery bags from Stop & Shop to make sure everyone gets the same amount.

“It’s affecting my ability to let people take exactly what they want,” he said.

And at least one Island agency has been unable to source any food at all. Barbara-jean Chauvin, director of operations at the Martha’s Vineyard Boys and Girls Club, said at the April 28 meeting that her organization is ready to open its own food bank for club member families, but can’t get the groceries.

“Our applications to the Greater Boston Food Bank have been denied,” Ms. Chauvin said.

Ms. Haag, who formed the food equity network in 2016 with the goal of connecting hungry Islanders with the meal and grocery services they need, said the supply shortages come as an unexpected setback.

“Getting access to food is a barrier I would never have anticipated,” she said.