Rare Appearance of Blacktip Sharks Draws Attention in Ilha Grande (RJ)

Divers and researchers were treated to an exciting surprise this week: numerous blacktip sharks were spotted swimming through the waters of Ilha Grande Bay in Angra dos Reis, Rio de Janeiro. This species, considered threatened with extinction, was seen in Piraquara de Fora Cove — an area within the Tamoios Ecological Station, a strictly protected marine reserve.

Stunning footage captured by the Sharks of Ilha Grande Bay Project shows dozens of sharks gliding peacefully through the area. Although the exact number of individuals hasn’t been confirmed, the sighting is considered highly significant.

“We’re witnessing a rare and important event for the conservation of coastal sharks in the South Atlantic. It’s also important to note that the presence of these animals poses no danger to swimmers,” said Fernanda Rolim, a researcher from the University of São Paulo.

While this isn’t the first time the species has been spotted in the region, the repeated nature of these sightings has caught scientists’ attention. Since 2016, research has been ongoing after a large group of sharks was recorded in the same area during this time of year.

One possible explanation, suggested by the Mar Urbano Institute, is that the sharks are drawn to warmer waters during the autumn and winter months. This movement appears to be linked to reproduction. Researchers observed pregnant females, and data suggest that warmer sea temperatures may support embryonic development and digestion, potentially even reducing gestation time.

“We’ve seen a consistent pattern of these sharks returning to the same area year after year, which indicates that this cove may serve a critical and predictable ecological role. This strengthens its case as a priority conservation zone,” explained Leonardo Mitrano Neves, scientific coordinator of the project.

Recently, Piraquara de Fora Cove was officially added to the list of Important Shark and Ray Areas by the International Union for Conservation of Nature (IUCN), further highlighting its environmental importance.

“This is a dive spot rich in biodiversity and popular among divers. The presence of keystone species like sharks is vital for maintaining the balance of marine ecosystems. Protecting them means safeguarding the entire habitat,” said Nathan Lagares, from the Mar Urbano Institute.

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