The urban metamorphosis of La Manga and the mediterraneanisation process of the Mar Menor (Spain)

La Manga del Mar Menor is an ancient dune line located in the Murcia Region (Spain). This area had an accelerated urbanization process starting in the 1960s which has had several powerful impacts on the coast, the landscape and the marine ecosystem. Among these impacts, the so-called process of mediterraneanisation of the inland lake is particularly interesting. The Mar Menor is a salty lagoon of more than 170 km2 and uniform drafts about 5 meters deep. This lagoon is a former bay of the Mediterranean Sea closed in a natural way by the sandbar of La Manga with a length of about 20 km. In 1950, this sandbar was a desert land. In around 1960 there was a tourism project to host up to 60,000 people. At present, it receives up to 250,000 people in the summer, mostly of Spanish origin. The urbanization process changed the system water flows between the inside and the seawater through channels called golas . The changes affected the coastal dynamics, the longitudinal profile of the coast and the lagoon ecosystem. Three processes in particular have caused major environmental impacts: land filling of water areas for the construction of infrastructure and building, connecting islands with routes and expanding channels and building ports for use by recreational vessels. Fifty years after the initial process, this paper analyzes the current coastal pathologies and how the urbanization process has caused them.