RIO DE JANEIRO (AP) Olympic sailors competing in the Rio de Janeiro may navigate through fetid waters and possibly bump into floating trash. But if they are lucky enough, they might also sail past a few dozen dolphins that live in Guanabara Bay.
Despite the untreated sewage and toxic industrial pollution that flows into bay waters, 34 Guiana dolphins live, breed and feed in the bay.
Still, the dolphin population here is in rapid decline, down from 400 in the 1980s, according to marine biologists who track them.
Scientists warn that the grey mammals with bottle-neck shaped noses that adorn Rio de Janeiro's city logo could disappear from Guanabara Bay in a matter of years.
''This is our backyard,'' said Rafael Ramos, a researcher with the Maqua institute at Rio de Janeiro state university that has monitored the dolphin population in Guanabara Bay since 1992. ''It must be treated as a gem.''
While the rivers that flow into the bay are dark and thick with raw sewage and toxic chemicals, at the bottom end of the bay, the Guapimirim conservation area serves as a refuge for these dolphins.
Yet researchers say the mammals transit in other parts of the bay as well, swimming around countless cargo ships, oil tankers, fishing boats and cruise liners.
Unlike other species, the Guiana dolphins do not migrate or flee their habitat to look for a new home when threatened by human growth and development.
Consequently ,many dolphins die early and frequently. Every year, several are found floating lifelessly in the bay and their corpses are taken in by Maqua researchers for study.
While causes of death can vary, they all originate in the degradation and human exploration of the bay says Haydee Cunha, a biology professor at Rio's state university who studies the genetics of the Guiana dolphins at the Maqua Institute.
''Unfortunately, if we don't do anything to change this scenario, in a few years, perhaps in a decade, the Guiana dolphins will disappear from Guanabara Bay,'' said Cunha.