Iranian Wetlands

The Hamoon Wetland

Wetlands occupy the transitional zone between permanently wet and generally dry environments, sharing characteristics of both aquatic and terrestrial environments but not belonging exclusively to either. Under the Ramsar Convention, wetlands are defined as “areas of marsh, fen, peat land or water, whether natural or artificial. For years, the ecological importance of the Hamoon Wetland was not well known. It was merely used for feeding the livestock and catching birds and fishes.

This wetland is located between 31^o15’ and 31^o32’ latitude as well as 60^o39’ to 61^o35’ longitude. The total area of this wetland varies between 350,000 ha and 130,000 ha. It depends on the rate of precipitation and water flow to the wetland. It includes three smaller wetlands called Saberi, Hamoon-Poozak and parts of Hamoon-Heermand. The protected area in the region is about 193,000 ha. This wetland is a great habitat for different animals and plants. The Heermand River pours into this wetland and provides the necessary water for the survival of this water body. The freshwater plays a great role in soil fertility, fish and bird habitats, as well as plant variety. The hydrological and geo-morphological conditions affect the life in the wetland.

The Hamoon Wetland is classified as a freshwater wetland. The water level depends on the rate of precipitation in the region, and therefore, there are large seasonal variations. The average precipitation rate in the province is 60 mm. The Heermand River plays a vital role in the province of Sistan-Balouchestan. This river, being also important for Afghanistan, is the main water body in the province.

The life forms in the wetland depend on specific physical, chemical, and biological parameters. Flora and fauna in this wetland enjoy rich biodiversity.

Ecological Importance

The main benefits of the Hamoon can be summarized as follows.

This Wetland acts as a natural dam and collects the seasonal floods in the region. This prevents the damages to nearby communities and human activities,
This Wetland prevents land erosion in the region. This is achieved by reducing the water flow and collection of sediments. This has a great positive impact on sustainability of agriculture activities in the region.
The wetland acts as a natural waste treatment plant. The wetland acts as a sink and a source of nutrients (such as nitrogen and phosphorus). The water plants absorb these nutrients. The photosynthesis by water plants and absorption of nutrients reduce eutrophication in the lake. On the other hand, the wetland acts as a source of nutrients. For example, through nitrification, nitrates are released as nitrogen to the atmosphere.
The wetland is an important habitat for plants and animals. Located near desert ecosystems, this wetland supports the food chain in the region.

The Hamoon Wetland has international significance. It is listed as one of the important Iranian wetlands under the “Ramsar Convention”. Many endangered animal and plant species are observed in this unique ecosystem.

Biodiversity of the Wetland

Schizothorax zarudny, Cehizopigopsis stolicglea, Discogenathus sp., Schizocypris brucei. Many exotic fish species are observed in this wetland including grass carp Ctenopharyngdon idella, common carp Cyprinus carpio, bighead Aristichthys nobilis, silver carp Hypophttalmichthys molirix, and goldfish Carassius auratus. The most common plankton species belong to the classes of Daphnia and Cyclops. Two freshwater frog species, namely, Bufo stomaticus and Bufo surdus are observed in the region. Some of the plant species include Alisma, Aeluropus, Cyperus, Cynodon, Butomus and Phragmites. Many bird species migrate to this wetland during the cold seasons, a few of which include ducks and geese.

Many mammals depend directly and indirectly on this water body. A few of these mammals include mice, fox, and boar.

Economic Values of the Wetland

Today, this wetland plays an important role in the socio-economic development of the region. Agriculture is solely dependent on the Hamoon. The wetland is an important feeding and grazing ground for livestock. According to 1983 statistics, more than 780,000 livestock were observed in the region. There are also local handicraft artworks, made by local material, in nearby communities, which support the local business activities.

Catching fish is one of the other sources of income for local communities. Unfortunately, many exotic fish species were introduced to this wetland, which had adverse impacts on the ecosystem. Fishing is carried out by traditional methods in the lake.

Major threats

The Hamoon Wetland is very vulnerable to water flow fluctuations.

Overgrazing
Drainage water from agriculture activities
Cutting plants
Introduction of exotic aquatic species
Low water depth and high evaporation rates
Lack of integrated management plan.

In the dry seasons, the texture of sediments at the bottom of the dried lake is very light, whereas in the regions with silt sediments, the soil is much heavier. The average water depth was used to be about 6 m, but currently this level is about 1.5 m to 2.0 m.

Loss of plant coverings and lack of management plans have encouraged sedimentation process in the lake. If this lack of management plans continues, the water storage capacity and water depth in the wetland will further decline. This matter would have negative impacts in the future. The flash floods would endanger nearby communities and agriculture areas.