Deforestation and decrease in the flow of freshwater into the sea, the mangroves forests of Indus delta, covering an area of about 600,0000 hectares, constitutes an important ecosystem is in danger.
All the species are dependent on the fresh water, although mangroves thrive in saline water, they require inflow of fresh water through rivers of nourishment.
The Indus delta mangrove ecosystem provides habitat for fish, plants, crustaceans, birds, mammals, reptiles and amphibians. According to a Zoological Survey of Pakistan, 98 species of fish have so far been recorded in the Indus delta mangroves. Most of the fish are attracted towards mangrove swamps during high tide periods due to nutrient-rich food sources present in these areas. The presence of three species of lizards and 14 species of snakes exhibit a very good example of overlapping of terrestrial and aquatic fauna. The evergreen forests of Indus delta mangroves provide a habitat for many of the waterfowls. Migratory birds, such as flamingos, pelicans, cranes, cormorants, in floks of thousands visit the Indus delta for feeding, roosting and breeding from November to February every year. It has been observed that the population of migratory birds has declined due to degradation of habitat during the last decade. Similarly, the number of sea dolphins has also reduced in mangroves due to marine pollution. (https://sindhforests.gov.pk)
Pakistan’s coastline is approximately 1,000 kilometres long of which Sindh’s share is around 350km. The provincial coastline comprises 17 large creeks and swamp areas and numerous small ones where mangrove forests thrive.
Mangroves cover an area around 600,000 hectares in Sindh, of which 280,470 hectares are owned by the provincial forest department. These forests consist of four mangrove species which include Avicennia marina, Rhizopora mucronata, Ceriops tagal and Aegiceras corniculatum. The most abundant species is Avicennia marina which constitutes up to 90% of the total mangrove population in the province.
In recent years, mangroves have been adversely affected due to sea intrusion, as supply of fresh water to the delta of the Indus River has been decreasing. The area around the delta has become saline and mangroves, which need some freshwater supply, are not prospering due to this.
The decrease in mangroves has also resulted in a decrease in marine life near the delta. Resultantly, fishermen have started migrating from these areas due to lack of resources in the water.
Commenting on the issue, Forest Department Mangroves said the department has been working for the conservation of mangroves, adding that currently the department is also engaging people living along the coast for the purpose. Fifty households are being paid for the conservation of mangroves, the officer said.