The 3,740 lives lost so far in 2016 "is the worst we have seen," William Spindler, agency spokesman, said Oct. 25 at a press briefing in Geneva. For all of 2015, the agency said, 3,771 refugees lost their lives on the sea.

"This year so far, crossings stand at 327,800. From one death for every 269 arrivals last year, in 2016 the likelihood of dying has spiraled to one in 88. On the central Mediterranean route between Libya and Italy, the likelihood of dying is even higher, at one death for every 47 arrivals," Spindler said.

Among the reasons for the increased death rate, he said, is increased use of the more dangerous route from North Africa to Italy; about half of those who perished at sea were traveling that route.

While many boats have capsized due to bad weather, Spindler said human traffickers also have smuggled thousands of people at a time using "lower-quality vessels – flimsy inflatable rafts that do not last the journey."

"This may be to do with the shifting smuggler business model or geared toward lowering detection risks, but it also makes the work of rescuers harder," he said.

Acknowledging those providing asylum and assistance for countless refugees who have successfully entered Europe, Spindler praised governments and private entities for their contribution "to the important work of saving lives."

However, he also urged countries to "do more in this regard," including the expansion of safe and legal pathways for refugees, enhanced resettlement, family reunification, as well as the provision of humanitarian, student and work visas for refugees.

The high rate of deaths at sea, Spindler said, is "a reminder of the importance of continuing and robust search and rescue capacities – without which the fatality rates would almost certainly be higher."