Newswise — The marine habitats in the South Atlantic Ocean have undergone a notable decrease in the past years as a result of excessive fishing and degradation of their surroundings. This fact has been revealed through a scientific investigation directed by the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB). The study provides insights into the extent of human influence on these formerly prosperous marine regions by examining fish remnants from various locations in Brazil using archaeological techniques.

The ancient native societies residing along the southern coastline of Brazil had the privilege of thriving in bountiful and varied marine environments, abundant with substantial fish populations and apex predators. These resources played a crucial role in securing their food supply throughout history. Consequently, these indigenous communities were able to periodically exploit these marine resources using rudimentary fishing techniques for countless generations. However, a comparative analysis between archaeological fish remains and contemporary fish populations has revealed a substantial decline in numerous species, especially sharks and rays. This decline is likely connected to the escalating effects of human activities, including overfishing and the deterioration of habitats, which have intensified in recent decades.

Thiago Fossile, the primary author and researcher at ICTA-UAB and the UAB Department of Prehistory, highlights the mounting anthropogenic pressures that aquatic fauna in Brazil, a nation renowned for its breathtaking beaches and rich biodiversity, are encountering. Fossile underlines that numerous species, once recorded in archaeological sites, are now facing the threat of extinction. Additionally, insufficient information exists regarding the distribution and population size of other species. By harnessing the power of archaeological data, it becomes possible to acquire valuable knowledge about these vanished ecosystems and subsequently redefine conservation benchmarks for their protection.

André Colonese, the senior author of the study and a researcher at ICTA-UAB and the Department of Prehistory at UAB, emphasizes the crucial role played by coastal and marine ecosystems in supporting subsistence fisheries along the Brazilian coastline for millennia. Colonese highlights that the wealth of information derived from hundreds of archaeological sites is invaluable for understanding past biodiversity, thereby contributing to discussions on fisheries management and conservation efforts. This study underscores the importance of integrating archaeological data into conservation dialogues in Brazil, thus strengthening the relevance of the field in addressing environmental challenges.

Mariana Bender, a co-author from the Universidade Federal de Santa Maria, expresses how the study provides a fresh perspective on comprehending the historical exploitation of fish biodiversity. She highlights the remarkable insights that archaeological sites can offer regarding the impact of ancient human communities on fish diversity. By examining the characteristics of fish remains, the study reveals evidence indicating that large apex predators have been subject to exploitation for an extensive period, while contemporary fisheries have shifted towards targeting lower trophic levels. Bender asserts that this phenomenon is not a recent development but has persisted for thousands of years.

Dione Bandeira, a co-author from the Universidade da Região de Joinville in Brazil, emphasizes the significance of Indigenous environmental stewardship as a blueprint for sustainable resource management and the conservation of biodiversity in tropical and subtropical areas of South America. Bandeira highlights the importance of studying archaeological faunal remains, which offer valuable insights into the origins and evolution of these enduring practices. Such studies shed light on the historical context and provide a deeper understanding of the long-standing traditions and knowledge systems that have contributed to the preservation of ecosystems in the region.

The study received funding from the ERC TRADITION project (Consolidator Grant 817911) and was conducted by researchers from ICTA-UAB (Spain) in collaboration with various institutions, including Rheinische Friedrich-Wilhelms-Universität (Germany), Universidade de São Paulo (Brazil), Universidade Federal de Pelotas (Brazil), Universidade Federal do Rio Grande (Brazil), Universidade da Região de Joinville (Brazil), and Universidade Federal de Santa Maria (Brazil). The collaborative effort among these institutions allowed for a comprehensive exploration of the subject matter, benefiting from diverse expertise and resources.

The study was funded by the ERC TRADITION project (Consolidator Grant 817911) and led by researchers from ICTA-UAB (Spain), in collaboration with the Rheinische Friedrich-Wilhelms-Universität (Germany), Universidade de São Paulo (Brazil), Universidade Federal de Pelotas (Brazil), Universidade Federal do Rio Grande (Brazil), Universidade da Região de Joinville (Brazil) and Universidade Federal de Santa Maria (Brazil).

Journal Link: PLoS ONE