The importance of these fortifications was early recognized as English, French, and Dutch sea marauders attacked the city in the 16th century.
[3][4] On March 4, 1960, the harbor was the scene of a deadly explosion when the French freighter La Coubre, carrying 76 tons of Belgian munitions, was being unloaded.
The cause of the blast, which killed an estimated 100 people, is often attributed to the CIA who wished to overthrow the new government of Fidel Castro.
[7] Water entering the bay as river flows or effluent from industrial processes has a residence in the harbor of 8 days, on average.
Havana Bay is strongly affected by sewage dumping, and it also receives suspended solids, hydrocarbons, heavy metals and pollutants from agriculture, industry and port activities.
The leading sources of pollution in the bay have been identified as the Luyano River which contains organic material, nutrients, sewage, solid waste,[8] the Regla oil refinery, fish hatcheries, and port activities.