Runoff from agricultural fields in the drainage basins of the Arani and Kalangi rivers into the lagoon has increased pollution load from fertilizers and pesticides; pollution from domestic sewage is also being released to the lagoon. A petrochemical complex, power plant and a satellite port on Ennore creek have further aggravated the problem; there is threat of flooding of 14 island – villages of the lagoon; subsequent to the tsunami in 2004, the number of fishing boats have increased resulting in the "Catch Per Unit Effort" of fish, prawns and crabs declined from 1000 tonnes to about 700 tonnes; and this has increased the social and fishing rights conflicts between marine based fishermen and the lagoon fishermen.