Lanzanillo Pajonal-Fragoso Animals Shelter is a protected marine area with 76,490 Ha and in its land territory is located Nazabal Bay, with natural conditions to maintain manatees due to it has see beds vegetation that provide the diet as well as rivers that flow to the Bay and serve as drinking fresh water. There were collected data of dead individuals including 12 adults and a baby from 1987-2008, doing patrols along the coast. To determine possible causes of death it was taken into account that the fishing gear coincided with the stranding. It was drawn up a database of each analyzed specimen and it was determined that the chinchorreo gear was affecting the species. Nazabal Bay was declared a protected or under special use and protection area by the Secretary of the Advisory Committee on Fisheries. The chinchorreo gear in the bay was not completely removed, remaining a sector where that art of fishing is still practiced up to the present there have not caused more deaths.