Others bring in fish by land, in ice-packed plastic foam boxes pulled through smuggling tunnels from Egypt. And even though the Mediterranean is right on Gaza's doorstep, locals are creating fish ponds to provide Gaza's 1.5 million people their key source of protein.

“People are searching for any solution,” said fisherman Adnan Abu Rialeh, 50, who sailed toward Egypt's Port Said three times in the past month to buy sardines. “If we could only go and fish in our sea, I could make some money and put it in my pocket,” he said.

Gaza's 3,600 fishermen are not allowed to go out further than 3 nautical miles (5.5 km). If they cross the line, they risk coming under fire from Israeli gunboats.

Five fishermen have been killed, more than 20 wounded and dozens arrested in attacks on boats, said the Israeli human rights group Gisha.

The permitted zone is overfished and cannot sustain the fishermen, said Nizar Ayyash, head of the fishermen's union. “It's not a sea for fishing, it's a pool for fishing,” he said.

The sea blockade is part of the closure of Gaza by Israel and Egypt.

The fishermen say they are not engaged in politics, and that Israel is destroying a way of life that once provided 5,000 jobs and made up 4 percent of Gaza's economy.

At dawn on a recent morning, men in waterproof overalls silently unloaded boxes of Egyptian sardines from a boat in Gaza City's small harbor. At the nearby fish market, most of the sardines on offer were Egyptian imports, said Mohammed Al-Hissi, an activist in the fishermen's union.

He said 30 Gaza boats returned from Egypt that morning, carrying several tons of sardines compared to a local catch of just 200 kilograms of shrimp, 300 kilograms of crabs and 500 kilograms of assorted fish.

Abu Rialeh, a fisherman since childhood, said the trips to Egypt began about a month ago, with just a few taking the risk. Now, dozens make the dangerous journey every day in small motorboats hugging the coast to avoid Israeli patrols. The journey can take six to 12 hours in each direction, and so far the Egyptian authorities have looked the other way.

But even the door to Egypt is closing. Abu Rialeh said he won't be making another trip into Egyptian waters because the fuel costs are eating up his profits.

The Egyptian fish are also reaching Gaza in other ways. On a recent evening, Palestinian workers hauled four plastic foam boxes with sardines packed in ice through one of the smuggling tunnels running under the border with Egypt. The boxes were hoisted by a homemade pulley, then loaded into a truck for the drive to Gaza City, 45 minutes away.

Perhaps the only low-risk way of supplying fish these days is to grow it. Several fish farms have popped up in Gaza in the past two years to fill the shortage created by the blockade. One of the farms is run on the lands of a former Israeli settlement.