Introduction to Wetlands by Dhaval Vargiya
(last modified on 27-09-15)
Wetlands are one of the crucial natural resources. Wetlands are areas of land that are either temporarily or permanently covered by water. This means that a wetland is neither truly aquatic nor terrestrial; it is possible that wetlands can be both at the same time depending on seasonal variability. Thus, wetlands exhibit enormous diversity according to their genesis, geographical location, water regime and chemistry, dominant plants and soil or sediment characteristics.
The Ramsar Convention, which in 1971 brought a worldwide attention to wetlands, took a broad approach in its definition “Wetlands are areas of marsh, fen, peat land or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres”.
Wetlands of Gujarat
The state of Gujarat is situated on the west coast of India, bounded by the Arabian Sea in the West, Rajasthan in the North and North-East, and Madhya Pradesh in the East and Maharashtra in the South and South East. The state also shares an international border with Pakistan at the north western fringe. Gujarat mainland region receives an average annual rainfall of 800 to 2000 mm, while Saurashtra has an average annual rainfall of 400 to 800 mm. The average annual rainfall in Kachchh is less than 400 mm. The incidence and distribution of rainfall, particularly in Saurashtra and Kachchh regions and in the northern part of Gujarat region, is highly erratic. The state has the longest coastline of about 1600 km (106 km in Porbandar).
Total 14183 wetlands have been identified in the Gujarat. The coastal wetlands dominate in the state. Some of the unique wetlands like corals and mangroves are found in Gujarat state. The water spread of wetlands is low during pre monsoon, particularly; it is significant in case of Inland wetlands indicating rain fed nature of the wetlands. Area under aquatic vegetation is slightly more in pre-monsoon season (205159 ha) than in post monsoon (152318 ha). Kachchh, Jamnagar, Bharuch, Bhavnagar, Porbandar and Surat are wetland rich districts mainly due to coastal wetlands. Though many wetlands of the state support high waterbird diversity and abundance, they have been facing 26 types of threats that may pose a challenge to their sound health as waterbird habitats. To cope up with these adverse factors, wetland management efforts ranging from assigning PA status to the wetland-based IBA sites and potential Ramsar Sites to weed control, water-level management and wise use for recreation should be considered. As there are different types of wetlands in the state that function as waterbird habitats, their types (e.g., dam, irrigation reservoir, natural lake, village pond, urban reservoir, marshy area etc.) should be taken into account while planning and implementing management strategies.
Wetlands of Porbandar
Porbandar can be described as plain sloping from Barda hills to the sea-coast, near which are tracks of marshy land known as Ghed. Total 226 wetlands are mapped including 95 small wetlands (< 2.25 ha) with 22199 ha area in Porbandar district. Inland wetlands contribute 27.3% of the total wetland area and coastal wetlands contribute 72.7% of the total wetland area. Major wetland categories of the district are Lagoons, Rivers/ streams, Reservoirs and Sand/beach. Area under aquatic vegetation in post-monsoon is about 5451 ha. Open water spread of the wetlands is significantly higher in post monsoon (13390 ha) than during pre monsoon (7376 ha). Mokarsagar Wetland Complex (previously known as Gosabara) is the name given to the cluster of wetlands including Medha creek, Kuchhadi, Subhashnagar, Zavar, Karly I, Karly II, Vanana, Dharampur, Gosabara, Bhadarbara, Mokarsagar, Bardasagar and Amipur wetlands of Porbandar district of Gujarat.
Ecologically Mokarsagar wetlands complex represents a diverse biotope. The wetland complex is a lifeline for the community as well as the wetland dependent biodiversity including both the flora (mangrove, macroalgae, macrophytes) and fauna (birds, reptiles, insects and mammals). A continuous stretch of Porbandar Bird Sanctuary, Chaaya –I, Chaaya-II and Porbandar Rann talao forms a Rann of approximately 10 sq km which is separated from the Mokarsagar wetland complex through a Jadeswar Road.
Kuchhadi–Jhavar wetland adjacent to Shaurastra salt pan in Subhashnagar (also known as Karly creek) is another wetland complex of 4-5 sq. km is connected with the wetland complex through a patch of tidal mud with of 4-5 km mangrove patch via Karly I and Karly II wetlands. While two manmade Amipur reservoir of 15.81 sq km and Barda Sagar of 18-20 sq. km are important wetlands which during heavy rainfall attach with each other to form a vast expand of water of about 200 sq km.
Shree Sahajanand Swami District Community Science Centre (SSDCSC)- Porbandar in the collaboration with Porbandar Forest Division- Porbandar, Indian Coastguard- Porbandar, Green Wildlife Conservation Society and Mokarsagar Wetland Conservation Committee organised Asian Waterbird Census (AWC) on 1st February- 2015 at 21 different sites of Porbandar district and recorded 1,93,358 waterbirds.
1. SAC/RESA/AFEG/NWIA/ATLAS/21/2010. National Wetland Atlas: Gujarat. Ahmedabad: Space Applications Centre, ISRO, 2010.
2. Dordio Ana, Palace PC, Paula P. In: RE R, Editor. Wetlands: ecology, conservation and restoration. New York: Nova Science Pub Incorporated; 2008. 18.
3. Varagiya DC, Sahoo N, Bhanuprakasdas SS, et al. Asian Waterbird Census (AWC) 2015 Porbandar. Porbandar: Shree Sahajanand Swami District Community Science Centre, 2015.
4. Varagiya DC, Chakraborty A, Joshi K. Ecological importance of Mokarsagar Wetland Complex over Gosabara wetland of Porbandar, Gujarat. Porbandar: Mokarsagar Wetland Conservation Committee, 2015.