The Argentine province of Río Negro continues its ambitious scientific research program to gain a deeper understanding of the lives of sharks, rays, and chimeras that inhabit the San Matías Gulf. During August, a team comprised of the Por el Mar Foundation, the Condros Group of CIMAS (Center for Marine and Aquatic Research), and the Secretariat of Environment and Climate Change conducted the winter campaign as part of a year-round seasonal monitoring program.
The main objective is to establish a solid baseline on the presence, distribution, and behavior of these species, scientifically known as chondrichthyes. To this end, four strategic points on the northern coast of the province have been selected: Pozo Salado, Caleta de los Loros, Bahía Creek, and Promontorio Belén. At each of these locations, three records are taken per station, allowing for comparison of data obtained at different times and the detection of seasonal patterns.
A non-invasive methodology
To conduct the surveys, researchers use remotely operated underwater video stations (ROUSs) with bait, known as BRUVs. This technique allows them to observe the animals in their natural habitat without capturing or handling them, minimizing stress and ensuring natural behavior. Thirty dives were carried out during the last winter campaign , and the resulting video footage is currently being analyzed.
The preliminary results have already yielded valuable data. During the campaign conducted in early 2026, 30 standardized sampling points were established , and more than 40 hours of audiovisual recordings were collected. Analysis of this material has confirmed the presence of five species: roosterfish, tope shark, smooth-hound, leopard shark, and stingray. All of these are listed in some threat category by the International Union for Conservation of Nature (IUCN), underscoring the urgent need for accurate and systematic information on sharks at risk of extinction.
Signs of breeding areas
One of the most significant findings has been the detection of juvenile specimens in certain areas of the gulf. This data could indicate that some areas serve as breeding grounds , a crucial aspect for the conservation of these species. However, researchers caution that further data is needed to confirm the importance of these sites and understand their role in the life cycle of chondrichthyans.
The vulnerability of these animals is well known. As Victoria Brizio, a biologist with the Por el Mar Foundation, explains, “Sharks have very long life cycles: they take many years to reach maturity and reproduce. This makes their populations especially sensitive to impacts, with consequences that are difficult to reverse.” Chondrichthyes, in general, exhibit slow growth and low fecundity, which limits their ability to recover from environmental or human pressures.
The Big 5 Corridor
This monitoring is not an isolated project, but rather part of a broader provincial strategy: the Big Five Corridor. This initiative covers more than 150 kilometers of coastline between Viedma and San Antonio Este and integrates research, conservation, and sustainable development. The corridor focuses on five key representatives of Patagonian marine biodiversity: the southern right whale, the orca, the bottlenose dolphin in the San Matías Gulf , the South American sea lion, and, of course, sharks.
The incorporation of regular scientific campaigns allows for the generation of local knowledge about the region's natural resources and provides tools to reconcile ecosystem protection with the economic and tourism activities that take place along the coast. For Río Negro, supporting this type of research is fundamental for evidence-based management.
The surveys will continue in the coming seasons with the aim of completing the series of records and deepening our understanding of the species that use the San Matías Gulf. The data obtained will be key to guiding future management and conservation decisions, and to consolidating the Big Five Corridor as a model for the protection of marine natural heritage.