Effect on Mangrove Forests in Sindh 

In the Indus delta, about 650,000 acres of mangrove forest, the sixth largest in the world, lie dependent on the nutrients from the silt carried by the waters of River Indus.
According to an IUCN paper of 1991 "The mangroves are the principle components of the delta ecosystem. Without them and the nutrients they recycle, and the protection they provide, the other components of ecosystem will not survive. Mangrove estuaries provide ideal nursery grounds for many commercial fish species , especially prawns". 

Another IUCN report on the Korangi Ecosystem, 1991, state; "The other wildlife species supported by mangroves is porpoises, jackals, wild bears, reptiles, migratory fowl bids and three species of dolphins. If the mangrove habitat is destroyed, the continued existence in the Indus delta of all those will be threatened".

IUCN estimates the mangrove estuaries (like those of Indus delta) to be 4 to 5 times more productive than tropical estuaries without mangroves.

Apart from this, the Mangrove forests have the following advantages as well:

1. They provide timber resource for buildings, and fuel wood for the vast population living in coastal areas.
2. They provide fodder and grazing land for cattle, goats, camels etc.
3. They provide opportunity to hatch 44 different species of fish in the delta area
4. They provide livelihood to 85000 fisherman

 Like the "Katcho", the Mangrove forests totally depend on water in the River Indus, and with any reduction in the volume of sweet-water into their roots, they will dry up, resulting into the salt-water intrusion, and subsequent soil-erosion, over a short period of time.