Proposed Ramsar Guidelines For Designating Salt Flats as
Wetlands of International Importance
Submitted by the Mangrove Action Project
Salt flats are hypersaline flatlands partially or totally devoid of vascular vegetation. Salt flats
come in many shapes and sizes, have diverse origins and may be associated with coastal or
inland settings.
In inland arid or semi-arid tropical and subtropical settings they develop in deserts where
intermittent streams drain toward the center of a basin which is sometimes occupied by a
temporary salt lake or lagoon where water evaporates and dissolved salts accumulate. Often
these lakes dry up and only the salt beds of these remain. These are called Salinas.
Coastal Salt Flats are most extensive, and become a dominant landscape feature on gently
dipping coasts with marked tidal rhythms (macrotidal coastal margins) and dry climate where the
Potential Evapotranspiration (PET) exceeds Precipitation throughout the year, or where there are
prolonged dry seasons. They are characterized by very low gradient slopes (<1:1,000) and
tidal flooding by Spring or Equinoctial Tides. These extensive floodable areas act as natural
evaporating basins and high salinities develop in the substrate. Salinity levels rise beyond the
physiological tolerance of most plant species (pore water salinity level above 100), and the
substrate is bare. During the dry season these flats are also subject to extreme drying,
and during any month may be affected by alternating periods of flooding by spring tides followed
by drying. These salt flats are referred to as salt barrens, salt flats, salinas, salitrales, salares,
sabkhas, sebkhas, and by various local names such as apicum, albinas, kavir, takir among
many. Coastal salt flats usually develop between the Mean High Water Spring (MHWS) line and
the upland tidal boundary. Coastal Salt flat sediments are mostly fine-grained mud (silt and clay)
and fine sands. Extensive coastal salt flats are found on the west coast of Panama where salt
flats (locally known as albinas, cover more than 19,000 ha. Extensive salt flats are also
found on the Pacific coast of Ecuador particularly south of Bahia de Caraquez. Originally, and
until about 1977 more than 130,000 ha of salt flats (salitrales) were found within the provinces of
Guayas and El Oro Broad saltflats are associated with an extremely dry climate (<200 mm) and
the macrotidal regime of the Gulf of Guayaquil. In recent years, extensive areas of salt flats have
been eliminated for the construction of ponds for shrimp farming. By 1991 Ecuador had lost over
45,000 ha of salt flats.
Sabkhas (sabkha is the Arabic word for a salt flat) are extensive salt flats found in arid and semiarid tectonically stable coastlines. Good examples are found in the Arabian Gulf, Baja California,
Mexico and Sinai, Egypt. Salt flats are also found in King Sound (north western Australia) and
near salt marshes in the Gulf of Gabes (Tunisia), and behind a barrier lagoon coast in
Mediterranean Libya. There are Sabkhas on the Red Sea coast of the Yemen Arab Republic, with
salt ponds in the lower margins. The Arabian Gulf is characterized by a series of sabkhas that
stretch for some 320 km along the coast of the United Arab Emirates (UAE) reaching up
to 24 km wide. These sabkhas have intertidal zones 1 to 2 km wide. The sediments are
dominantly carbonate muds that have become colonized by blue-green algae that bind the
sediment to form thick algal mats. These mats are subject to intense surface evaporation and
heating.
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In inland settings extensive salt flats are found associated with beds of former salt lakes and
intermontane and endoreic drainage systems (systems that do not drain to the sea) and basins
such as those in the Altiplano basin that extends for approximately 1000 km from southern Peru,
across Bolivia and into Argentina and Chile. The floor of this basin lies at an elevation of 3750
?4000 m asl. and is some 200 km wide. The floor of the altiplano contains the sediments of
shrunken or extinct lakes. Several large salt flats and salt lakes and lagoons (salares) occur here,
including the Salar de Uyani and Salar de Coinasa.
On a more limited spatial scale, but locally important, salt flats (salinas) are linked to shallow salt
ponds in the insular Caribbean (a microtidal environment), salt ponds are formed where
mangroves or fringing coral reefs grow across inlets, or where active alongshore transport
deposits sand that blocks the entrance to a coastal lagoon. Evaporation in the closed basin is
high and fresh water flows from the small watersheds are very reduced and sporadic. As a result
the ponds dry up completely forming a salt flat with crystallized salt on the surface. The ecology
of these pond and salt flat complexes is very complex and dynamic. Occasionally the berms
blocking the ponds are breached by waves or are overtopped by storm water outflows from the
land. This allows reinvasion by marine animals, usually crabs and fish. These die off as the pond
recloses and salinity increases again. These alternating cycles of life and death result in the
release of large amounts of nutrients that become available following breaching and reinvasion.
Saline lagoons and salt flats are important to migratory shorebirds such as plovers and
sandpipers and migratory waterfowl such as blue-winged teal and several waders. The
mangroves that line these saline ponds and salt flats provide a habitat for nesting populations of
herons, pigeons and many songbirds.
Salt flats are threatened by the disruption of processes that maintain their ecological character
and integrity. This includes water diversions that reduce fluvial inputs of water and the direct and
indirect effects of urban, and industrial expansion, and coastal development and infrastructure
such as roads marinas, harbors, airports, as well as reclamation for agriculture and
aquaculture (fish and shrimp farms). Possible climate change as a result of the greenhouse
effect poses a particularly important threat to salt flats and associated ecosystems by changing
water budgets and hydrologic regimes.
In designating salt flats as Wetlands of International Importance, the administrative authority
should concentrate on the guidance provided by Ramsar's Handbook # 7 "Strategic Framework
and Guidelines for the Future Development of the List of Wetlands of International
Importance". The designation of wetland sites for their international importance should be
based on their "international significance in terms of biology, botany, zoology, limnology or
hydrology". Special consideration should be given to the listing of sites where there is a threat of
degradation, and where listing can lead to comprehensive management or internationally
coordinated actions that preserve the system's integrity and ecological character.
In applying Criterion 1, in terms of hydrology, Contracting Parties are urged to give priority to
salt flats that play a substantial role in the functioning of a major coastal landform system
such as a delta, coastal lagoon or embayment, and that contribute to the maintenance and
stability of these systems by providing protection from coastal erosion, and sediment sinks that
compensate for land subsidence.
In applying Criterion 5, Convention signatories should give priority to the designation of tidal
flats that are part of migratory routes, such as the Australasian Flyway, the West Pacific
Flyway, the Central Asian-Indian Flyway, the African-Eurasian Migratory Flyway, or the
Atlantic Flyway.
In selecting sites, the designating authority should consider those areas that: (a) have
remained largely intact and have suffered the least human-induced change, including physical
habitat alteration and pollution; (b) have the highest habitat diversity; (c) contain the greatest
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number of rare critical habitats, such as breeding and feeding areas, and sheltering areas for
juveniles; and (d) have the best habitats for endangered, threatened, rare or sensitive
species, or biological assemblages.
Designating authorities must also consider the need to protect selected sites against external
land-use changes and land-based sources of pollutants. A Coastal Wetland site is unlikely to
succeed unless it is established within an integrated management framework, such as that
provided by an Integrated Coastal Zone Management (ICZM) regime.
Salt flats can form, or be essential elements of landscapes that cover extensive regions (>1,000
km2), therefore the designated site must be large enough to encompass an entire selfperpetuating system or complex of salt flats and associated systems. To maintain the integrity of
the system it may be desirable to designate a network of sites that define an
ecologically functional unit. The ideal management unit consists of an integrated system that
includes highly protected areas that are managed for the highest level of protection, as well as
a suite of controls in other less sensitive areas to promote ecologically sustainable development.
The concept of protected landscapes (IUCN categories V and VI) is a relevant management
model for the conservation and sustainable use of tidal flats because these categories
encompass larger areas and a wider range of interdependent ecosystems than other IUCN
categories (6).
These IUCN categories of management also allow the greatest flexibility in terms of
meeting the necessary conservation and social objectives.
National governments have many obligations on the environmental front. These mechanisms
interlock, and should be mutually reinforcing. When designating salt flats as Wetlands of
International Importance, Contracting Parties are urged to consult IUCN's publication "A Global
Representative System of Marine Protected Areas" and to consider, as specified in Objective 4.2,
the opportunities that the designation provides for supporting established or developing flywaywide conservation initiatives under international or regional environment conventions and
programs, as well as supporting biodiversity conservation strategies, and regional
intergovernmental and non-governmental initiatives and projects that provide a framework for
international cooperation on issues related to the conservation of migratory waterbirds and their
habitats following an integrated flyway/ecosystem approach, such as: working with the
Convention on Biological Diversity (CBD); the International Waterfowl and Wetlands Research
Bureau (IWWRB now Wetlands International), the Agreement on the Conservation of AfricanEurasian Migratory Waterbirds (AEWA), The Pacific Waterbird Flyway Conservation Program
(Wetlands International), the North American Waterfowl Management Plan (NAWMP); the AsiaPacific Migratory Waterbird Conservation Strategy (APMWCS); the Council for Arctic Flora and
Fauna (CAFF); the Western Hemisphere Shorebird Reserve Network (WHSRN); and its bilateral
and "site twinning" examples.
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