And that number could rise further. More than 90 migrants are feared dead after their boat sank in the Mediterranean east of Tripoli, a Libyan coast guard spokesman, Ayoub Qassem, said Thursday. The coast guard said at least 29 migrants have been rescued, but survivors said 126 people had been on the inflatable boat, apparently seeking to reach either Malta or Italy.

All told, only about a third as many migrants have tried the sea crossing this year compared with last year. That means something about migration dynamics has changed to make reaching Europe three times as deadly.

The reasons are manifold. They stem from the unintended consequences of hard-nosed decisions by governments, as well as the inevitable consequences of reckless decisions by smugglers. Below is a map that can serve as a basis for understanding the shift in migration that has taken place over the past three years. The data come from the Missing Persons Project run by the International Organization for Migration, whose numbers are slightly different from those of the United Nations.

First, notice that incidents off the coast of Turkey tend to result in fewer deaths. Before March of this year, the relatively short sea crossing from Turkey to various Greek islands was the preferred route to Europe, especially for those fleeing the war in Syria, which borders Turkey. More than 1 million people arrived in Greece via this route between January 2015 and March 2016.

AD

AD

In March, the European Union and Turkey reached a deal. It stipulated that all immigrants arriving in Greece would be returned to Turkey, where they could apply for asylum. Although the deal didn't totally stop people from using the route, it dissuaded many. Refugee camps in Turkey, Lebanon and Jordan have swollen. Fifty-thousand refugees, mostly Syrians, are stuck in Greece after European nations reneged on pledges to resettle them across the continent.

So attention has shifted to what is known as the “central Mediterranean” route, from North Africa to Italy. The route accounts for about half of the total arrivals in Europe but most of the migrant deaths. Its watery graveyard is populated almost entirely by Africans fleeing conditions that although not warlike are dire, including extreme poverty and hunger.

“People are having to take a more dangerous route,” said Chris Boian, a spokesman for the U.N. High Commissioner for Refugees. “It's that simple.”

AD

AD

Weather is often worse in the central Mediterranean, he said, but distance is a more decisive factor. Patrol boats must travel farther for rescues. And the more time a boat is in the water, the more opportunity it has to sink. Especially when the boat is flimsy to begin with.

“It appears that smugglers [on this route] are using low-quality vessels. Some are basically just inflatable rafts packed to the brim with people,” Boian said.

William Spindler, Boian's counterpart in Geneva, said risky practices are becoming more and more common among smugglers based in North Africa.

“Smuggling has become a big business; it's being done almost on an industrial scale,” Spindler told reporters Tuesday. “So now they send several boats at the same time, and that puts rescue services in difficulty because they need to rescue several thousand people on several hundred boats.”

That “mass embarkation” strategy has resulted in single-incident death tolls reaching into the hundreds.

AD

AD

More than 1,000 died off the Libyan coast in a single week in May. In September, 162 bodies were recovered from a wreck off the Egyptian coast. The incident that pushed this year's total over last year's occurred overnight Tuesday when a Doctors Without Borders rescue ship came across an inflatable dinghy with 107 live passengers and 25 dead ones. The dead were found crushed underfoot on the dinghy, in a pool of seawater mixed with fuel.

On Monday, about 2,200 migrants were rescued in the central Mediterranean in 21 operations. Only 16 bodies were recovered, according to the Italian coast guard, but a spokesman for the International Organization for Migration said survivors were certain that the toll was higher.

One out of every 47 people attempting the crossing from North Africa has died, Spindler said. When the route to Greece was in full swing last year, that number was one in 269.