Research studies indicate that pollutants found in fresh water may lead to a life of crime. The toxic chemicals, particularly heavy metals, can disrupt neurological control mechanisms that inhibit violent urges and make people, particularly children, more violent. Studies on chlorinated hydrocarbons show that attention deficit syndrome in children may be, in part, caused by these chemicals. An estuary is a semi-enclosed body of water which has a free connection to the open sea. Seawater is measurable in an estuary diluted with fresh water derived from land drainage.
Mangrove forests are one of the most productive and biodiverse wetlands on Earth.
Despite this, these unique coastal tropical forests are among the most threatened habitats in the world. They may be disappearing more quickly than inland tropical rainforests, and, with little public notice. Vast tracts of mangrove forests have been cleared to make way for the establishment of coastal shrimp farm facilities.