NE Argentina (San Miguel, San Roque, Corrientes), S Paraguay (Itapuá, Misiones)

The northeastern Argentina-southern Paraguay border region encompasses critical portions of the Atlantic Forest and Paraná River floodplains, representing one of South America's most biodiverse yet threatened ecosystems. This area supports exceptional freshwater mollusk diversity in the Paraná-Paraguay river system and harbors endemic invertebrate species adapted to the region's unique wetland-forest mosaic. According to IUCN Red List 2025 data, all 170 assessed species in this transboundary region are critically endangered, indicating an unprecedented biodiversity crisis. The region faces severe pressure from expanding soybean cultivation and cattle ranching, particularly in Paraguay's Itapuá and Misiones departments. Large-scale agricultural conversion has fragmented remaining Atlantic Forest patches, while dam construction along the Paraná River system threatens endemic aquatic species. Unregulated sand mining and urban expansion around Corrientes further degrade riparian habitats critical for mollusk populations. Binational conservation efforts include the proposed Trinational Biodiversity Corridor linking protected areas across Argentina, Paraguay, and Brazil. Argentina's recent expansion of Iberá National Park provides crucial habitat connectivity, while Paraguay has established new private reserves in Misiones department. However, enforcement remains inconsistent, and agricultural expansion continues to outpace protection efforts. The current trajectory suggests continued deterioration without immediate, coordinated transboundary intervention to halt habitat conversion and strengthen species protection measures.

Source: IUCN Red List 2025-2, GBIF, national survey data