Coastal saline marshlands develop in sheltered areas and are directly affected by how close they are to the sea, forming a link between the marine, freshwater and terrestrial environments. Marshland habitats support highly specialised species and, although several of them are common to all local salt-marshes, each site has its own particular characteristics and suite of species.

Salt-marshes are characterised by a muddy substratum on which a pool of brackish water collects in the wet season.

During the summer months this water becomes progressively more brackish until it becomes hyper saline and finally disappears completely, leaving the marsh dry until the following wet season. Not surprisingly, Il-Magħluq ta' Marsaxlokk supports several halophytic (salt-loving) species that are well adapted to the changing physical and chemical conditions associated with this habitat. This salt marsh represents one of the best Mediterranean salt meadows of the Maltese islands and is also very important for a number of invertebrates, some recorded only from this area.

Mepa scheduled Il-Magħluq ta' Marsaxlokk as a Level 1 Area of Ecological Importance and a Level 1 Site of Scientific Importance as per Government Notice No. 1069/06 in the Government Gazette dated December 19, 2006.