Photo

Migrants arrived on a beach Wednesday near Mytilene, the main port on the Greek island of Lesbos, after crossing from Turkey.Credit Tyler Hicks/The New York Times

MYTILENE, Greece — On this vacation island ringed by the clear Aegean Sea, it is now the tourists who are the rarity.

Arabic has surpassed Greek as the dominant language on the streets of Mytilene, the main port town. The beaches are festooned with orange life jackets and deflated rafts abandoned by migrants who are choosing to take their first steps into Europe here, in ever-increasing numbers.

As the authorities elsewhere in Europe are shutting their borders and struggling to deal with the migration crisis, Lesbos has been overwhelmed by an increasing flow of migrants who have arrived by boat from Turkey.

The humanitarian crisis the island faced this summer has diminished, partly because of streamlined registration for new arrivals and more ferries to carry migrants to mainland Greece.

But the island’s relatively calm waters and a Turkish crackdown on smuggling elsewhere after the widely publicized drowning of a Syrian toddler two weeks ago have rerouted much of the Mediterranean’s human traffic though Lesbos, making it the single largest European recipient of new migrants.

Migrants Flood Greek Island of Lesbos

“This is the main point of entry for Europe,” said Antonios Sofiadelis, of the Hellenic Coast Guard on Lesbos.

After sunrise on Wednesday, Safa Salem, a refugee from eastern Syria, stepped from a rubber raft stuffed with dozens of passengers and stood in Europe for the first time.

“I know I am in Greece, but I have no idea where,” he said, smiling.

The prime role of Lesbos as a migration route is largely an accident of geography. Turkey is so close that migrants have to cross as few as six miles of water to reach the island. And nearby Turkish shores are sparsely inhabited, making them ideal places for human traffickers to gather migrants and launch them in flimsy inflatable rafts.

While other Greek islands, like Kos and Khios, are also close to Turkey, the waters around Lesbos are relatively calm, making the crossing easier. And the maritime authorities in Turkey have cracked down on human smuggling farther south, according to Syrian smugglers in Turkey.

That crackdown has not been as strict near Lesbos, where arrivals have skyrocketed to more than 50,000 last month from 737 in January, Mr. Sofiadelis said.

Between 2,000 and 3,500 migrants now reach the island daily, riding on about 100 inflatable rafts. That is too many for the island’s 180 coast guard officers to handle, and many now work double shifts and carry out rescue operations when rafts pop or motors malfunction, stranding the migrants at sea.

For most migrants, who are coming from Syria, Iraq, Afghanistan and elsewhere, Lesbos is a mere way station on the way to mainland Greece and farther afield in Europe, although the island’s isolation has at times hindered that journey.

Earlier this month, a rise in arrivals and slow registrations led to a backup of more than 20,000 migrants on the island, nearly a quarter of its native population. The migrants protested the lack of services, blocking traffic and clashing with the police.

The Greek government has since streamlined registration and hired extra passenger ferries to get migrants to the mainland, said Djamal Zamzoum of the United Nations refugee agency on Lesbos.

Sitting in his office on this city’s U-shaped harbor, Spyros Galinos, the mayor of Lesbos, said he felt the island had been occupied by migrants.

Smoking both an e-cigarette and a real one, he called their arrival a humanitarian crisis but said he considered it unethical to view it in economic terms. Still, he said, the migrants had taxed municipal resources, causing 1 million euros, or about $1.1 million, in damages to infrastructure and exhausting the municipality’s yearly sanitation budget four months early.

The impact of the migrants is clear around town.

During the day, the streets are full of migrants speaking a variety of languages, lugging large backpacks and charging their phones for a fee at impromptu charging stations in cafes. Long lines form outside shops selling cheap gyros and in front of ferry company offices.

Graphic The Scale of the Migrant Crisis, From 160 to Millions The latest E.U. proposal addresses just a fraction of a human crisis numbering in the millions.