DNA metabarcoding and environmental DNA across Brazilian biomes: trends, challenges, and conservation applications

Brazil harbors the greatest biodiversity on the planet; however, the application of emerging technologies to enhance biodiversity assessment and monitoring remains limited. In recent years, DNA metabarcoding and environmental DNA (eDNA) surveys have revolutionized the assessment of biodiversity, offering new tools to evaluate ecological and conservation trends and patterns worldwide. Yet, their application in Brazil is still in its early stages, underscoring the paradox of a megadiverse country with limited adoption of cutting-edge tools for monitoring its natural wealth. This review provides a comprehensive synthesis of the application of DNA metabarcoding and eDNA analyses across different ecosystems in Brazil, integrating findings from 47 studies published between 2015 and 2025. Trends in ecosystem types, taxonomic groups, molecular markers, geographic distribution, and patterns of authorship and funding were analyzed. Most studies focused on terrestrial (42.5%) and freshwater (34%) environments, followed by marine (19.1%) and estuarine (4.2%) systems. DNA metabarcoding predominated in terrestrial studies (52.1%), while eDNA was more frequent in freshwater, marine, and estuarine environments. The mitochondrial 12S marker was the most widely used, primarily for detecting fish and amphibians. We observed a predominance of Brazilian first and senior authors, with weak signs of parachute science. However, challenges persist, including limited access to funding and underrepresentation of some biomes and taxonomic groups. Our findings highlight a growing national capacity in the use of DNA metabarcoding and eDNA research while underscoring the need for strategic investments in infrastructure, database development, and equitable scientific collaboration.