Lessepsian migration

The Lessepsian migration (also called Erythrean invasion) is the migration of marine species across the Suez Canal, usually from the Red Sea to the Mediterranean Sea, and more rarely in the opposite direction. When the canal was completed in 1869, fish, crustaceans, mollusks, and other marine animals and plants were exposed to an artificial passage between the two naturally separate bodies of water, and cross-contamination was made possible between formerly isolated ecosystems. The phenomenon is still occurring today. It is named after Ferdinand de Lesseps, the French diplomat in charge of the canal's construction. The migration of invasive species through the Suez Canal from the Indo-Pacific region has been facilitated by many factors, both abiotic and anthropogenic, and presents significant implications for the ecological health and economic stability of the contaminated areas; of particular concern is the fisheries industry in the Eastern Mediterranean. Despite these threats, the phenomenon has allowed scientists to study an invasive event on a large scale in a short period of time, which usually takes hundreds of years in natural conditions. In a wider context, the term Lessepsian migration is also used to describe any animal migration facilitated by man-made structures, i.e. one which would not have occurred had it not been for the presence of an artificial structure. The opening of the Suez Canal created the first saltwater passage between the Mediterranean Sea and the Red Sea. Constructed in 1869 to provide a more direct trade route from Europe to India and the Far East, the canal is long, with a depth of and a width varying between . Because the surface of the Red Sea is slightly higher in elevation than the Eastern Mediterranean, the canal serves as a tidal strait by which Red Sea water pours into the Mediterranean. The Bitter Lakes, which are natural hypersaline lakes that form part of the canal, blocked the migration of Red Sea species into the Mediterranean for many decades, but as the salinity of the lakes gradually equalized with that of the Red Sea, the barrier to migration was removed, and plants and animals from the Red Sea have begun to colonize the eastern Mediterranean.