The Dolphins Are Disappearing but Mangroves Give Hope to New Life in Rio's Guanabara Bay

Only 30 dolphins remain; the possibility of regeneration divides experts

When the promises of cleaning up Rio de Janeiro's Guanabara Bay first sprung up, there were still around four hundred Guiana dolphins circulating in the polluted waters. The mangroves, which covered the entire coast before the explosion of urban growth around it, amounted to just 60 square kilometers — less than a quarter of what they once were.

After 40 years of failed clean-up promises, the two symbols of what was once an unspoiled bay had different fates. There are currently no more than 30 dolphins, heading toward extinction in the coming decades. The mangroves, in turn, have already filled their protected area and are expanding to other regions.

Protected area in Guanabara Bay Crédito: Rodrigo Campanário / Projeto Uçá

The difference reflects the diversity of the environmental quality of the 328 square kilometers of the bay's water mirror, whose image is completely associated with sewage. It also shows the impact of pollution and nature's ability to recover.

The main area of ​​remaining mangroves is in the environmental protection area) of Guapimirim, at the bottom of the bay. Created in 1984, it guaranteed the survival of the ecosystem threatened by the extraction of wood for burning in the pottery ovens that operated around the bay.

In the 37 years of preservation, the entire area has been regenerated naturally or reforested. Currently, there is no space for replanting.

Translated by Kiratiana Freelon

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