The salterns around Torrevieja's area are fed by a mixed water supply; they receives sub-surface fresh water from further inland and salt water that enters through the channels that connect the lagoon with the sea. The part that is permanently under water is limited to the area of the saltworks, whereas the rest of the area suffers sporadic and variable flooding.
The typical vegetation is salt water, made up of species whose distribution depends on the presence of water and the degree of salinity. At one end of the scale, one finds communities of hyper-saline annual saltworts and salt grass, which gradually give way to perennial saltworts, species of sea lavender and many other species as salinity and humidity decrease. Some of these species are endemic (Limonium santapolense, etc.) and of great bio-geographic interest. Further inland, in the fresh-water zone, one finds hydrophilic communities of reeds and rushes making their contribution to the botanical diversity of the area.
The largest group of fauna to be found in the area is birds. The wetlands provide sanctuary to the largest colonies of wading birds in the whole Autonomous Community of Valencia during the migration and winter seasons. These include the avocet (Recurvirostra avosetta), the black-tailed godwit (Limosa limosa), several species of sandpipers, the kentish plover (Charadrius alexandrinus), the common redshank (Tringa totanus) and representatives of what are known as "sea swallows", such as the common tern (Sterna hirundo) and the lesser tern (Sterna albifrons). During the winter, there are large colonies of anatidae, mainly shovelers (Anas clypeata), red crested pochards (Netta rufina), common pochards (Aytha ferina) and green-winged teals (Anas crecca). These wetlands, along with El Hondo, shelter 80% of the European marbled teal (Marmaronetta angustirostris) population, classified throughout Europe as an "endangered species".
The flamingo (Phoenicopterus ruber) deserves a special mention. It is the symbolic bird of the park, living in the salt pans habitat throughout the year and reaching colonies of up to 8,000 specimens.