The Suez Canal is unique among the world’s canals as it has no locks, so seawater flows freely between the Mediterranean and Red seas. Because of the location of the Bitter Lakes in the middle of the canal, the current in the water north of the lakes reverses seasonally, going north in the winter and south in the summer. To the south of the lakes, the current is tidal, reversing course in sync with the Red Sea tides. Because of the free flow of salt water between the seas, fish are able to migrate, mostly to the north, where Red Sea species have begun to colonize parts of the eastern Mediterranean. This is known as the Lessepsian Migration, named after Ferdinand de Lesseps, French diplomat and developer of the Suez Canal.