A sharp increase last year in migrant deaths underscored the ever-more perilous journeys undertaken by those fleeing poverty and violence around the world.
The International Organization for Migration documented 7,763 deaths in 2016, a 27% jump over the previous year, according to a report it released Friday.
Most of the increase occurred in the Mediterranean Sea, despite the growing number of search and rescue operations deployed by governments and aid groups to help migrants when their rickety boats run into trouble on the dangerous crossing to Europe.
There were also significant rises in the number of migrant deaths in Africa and the Americas. Deaths dropped precipitously in Southeast Asia as the number of people using sea routes from Myanmar and Bangladesh to Thailand and Malaysia fell.
"I think we are still quite shocked by the figures," said Frank Laczko, who directs the IOM's Global Migration Data Analysis Center, which produced the report.
"There has been so much attention in the media and in policy circles given to the rising number of deaths," he said. "But despite all of that, we still see the number of deaths, particularly in the Mediterranean, rising quite significantly last year."
With heightened attention has come better monitoring and reporting, which could account for some of the increase, Laczko said.
But the analysis of the evidence also suggests that smugglers are becoming increasingly cavalier about the safety of their passengers, packing migrants into less seaworthy vessels — even during the winter months, when the Mediterranean is at its most dangerous.
The researchers drew on a variety of sources to compile the report, including local coast guards, medical examiners, humanitarian groups, interviews with survivors and media accounts.
Even so, the report said, many more deaths likely went unreported.
The Mediterranean Sea
At least 5,098 people died trying to cross from North Africa and the Middle East to Europe, a 35% increase over the previous year and a 55% increase over 2014. Most drowned, but 148 died because of conditions on the boats, including a lack of food and water.
Ten large shipwrecks in the Central Mediterranean accounted for more than half the deaths.
Since at least 2014, this has been the deadliest route for migrants trying to reach Europe, in part because of the longer distances traveled between North Africa and Italy than between Turkey and Greece. But the report said smugglers who ply this route are using more dangerous tactics, such as launching multiple boats at the same time, which makes rescue operations more difficult.
Most of the migrants who are headed to Italy depart from Libya, which has been engulfed in anarchy since the fall of its longtime strongman, Moammar Kadafi. Conditions there have grown so dire, that migrants may be willing to take more risks to get out of the country, Laczko said.
A total of 434 deaths were recorded on the eastern Mediterranean route from Turkey to Greece. Arrivals in Greece fell rapidly after the European Union began implementing a deal reached with Turkey last March to send back migrants who did not apply for asylum there.
More than 360,000 other migrants survived sea crossings to Europe in 2016, according to United Nations figures.
At least 1,600 migrant deaths were recorded in and around Africa last year, a more than 80% increase over 2015.
North Africa accounted for the largest share: 1,279 deaths. Collecting information about this region is especially difficult, because of the many different countries of origin and routes used.
However, the report noted that these routes frequently pass through the Sahara Desert, where the risks include dehydration, starvation and exposure to the elements. Migrants also described many instances of abuse by smugglers, including kidnappings, torture and killings.
At least 707 migrant deaths were recorded in the Americas, a 43% increase over the previous year.
They include 400 people who died along the U.S.-Mexico border, many of them on harsh treks through Texas' Rio Grande Valley and the Arizona Desert.
An additional 175 deaths were recorded in Central America, 27 in South America and 105 in the Caribbean Sea.