Tagging, ranging patterns, and behavior of franciscana dolphins ( <scp> <i>Pontoporia blainvillei</i> </scp> ) off Argentina and Brazil: Considerations for conservation

The franciscana dolphin, Pontoporia blainvillei, is one of the most threatened cetaceans in Southwestern Atlantic. Within their limited coastal range off Argentina, Uruguay, and Brazil, franciscanas face human activities, including artisanal gillnet fishing development. A lack information on ranging patterns, population structure, behavior for informing management led to efforts develop apply approaches tag Argentina (Bahía Samborombón [BS], Bahía San Blas [BSB]) Brazil (Baía Babitonga [BB]) during 2005–2013. Findings from VHF tags deployed BS 2005 feasibility tests catching handling tagging suggested residency over periods weeks. Subsequently, satellite-linked confirmed patterns at each site. Home size varied, with ranges 5–7 km2 BB, 51–312 BS, 49–1,014 BSB. Diving varied across sites, animals using entire water column, exposing them nets regardless depth which were set. Tracking durations follow-up observations indicated that this research approach useful studies franciscanas. Small, definable facilitate relating specific geographically based threats appropriate units, increasing potential effective conservation.