Greek coast guard statistics showed that at least 10,445 migrants entered Greece illegally through sea, during the first three months of 2015.
In March, 6,498 migrants have crossed over through the Eastern Aegean.
A dramatic three-fold increase compared to the first three months of 2014, when a total of 2,863 migrants were documented to have entered Greece illegally.
The islands that have received the greatest waves of migration are Lesvos, Chios, Leros and Samos.
Migration through sea has surged since the construction of a fence on the border with Turkey in the north of Greece and the ongoing conflicts in Syria and Iraq.