The wetland is an extensive coastal basin marsh separated from the shoreline by a long spit. As a typical marsh of the Mediterranean coast, the wetland was formed by the prolonged closure of a coastal bay by sedimentation processes. The waters in the marsh are permanent and relatively saline, due to the limited inflow of fresh water. The wetland is of great biodiversity interest as it contains up to 800 different species, several of them endemic such as Narcissus perezlarae, Valencia hispanica, Squalius valentinus and Cobitis paludica. In addition, 35 animal species found in the area are threatened, most notably the internationally vulnerable marbled duck (Marmaronetta angustirostris), which has been recently declared to be in a critical situation in the country. Main threats include the presence of invasive alien species, and human activities such as agriculture. The Muntanyeta information facility carries out educational activities in the area.