The United Nations refugee agency says 1500 would-be migrants, mainly from Somalia and other parts of Africa, died trying to reach European shores in 2011.
The agency says uprisings in Tunisia and Libya prompted more people to flee last year.
Most of the deaths happened in the first half of the year.
The toll is an estimate of those who drowned or went missing in the Mediterranean Sea, which divides Europe and Africa.
Altogether, more than 58,000 people arrived in Europe by sea last year, the majority of whom landed in Italy.
The UNHCR says half of them were Tunisian and most were migrants, not asylum-seekers.
More this year
Since the beginning of this year, at least three boats laden with migrants have been reported attempting to sail from Libya to Europe.
One boat with at least 55 Somali migrants capsized before reaching its destination.
Fifteen bodies including that of a baby girl, have been found.