Using spatio-temporal clustering to identify mortality patterns and anthropogenic drivers in the marine otter (Lontra felina) in north-central Chile

Toro F.; Mallea G.; Alvarado-Rybak M.; Toro-Barros B.; Alarcón J.; Trivelli J.; Calvo C.; Cruz-Jofre F.; Abarca-Mora P.; Leiva J.; Arriagada J.; Frenkel S.; Salah P.; Sepúlveda M.; Seguel M.; Medina-Vogel G.; Huerta-Santander T.; Pavez G. · Frontiers in Marine Science (2026) · DOI: 10.3389/fmars.2026.1835525

Resumen

Introduction – Small marine carnivores inhabiting fragmented rocky coastlines are increasingly exposed to anthropogenic pressures, yet mortality drivers in these systems remain poorly quantified. Methods – We analyzed 22 years of carcass records (2003–2024) and standardized necropsies to evaluate the contribution of anthropogenic causes and their spatial and temporal patterns in marine otters (Lontra felina) from north-central Chile. Results – We documented 173 mortality events involving 181 individuals. Space–time permutation analyses revealed three significant peri-urban clusters associated with areas of high human activity. Among cases with assigned cause, anthropogenic drivers predominated, particularly free-ranging dog attacks, followed by fisheries bycatch and non-specific trauma. Although seasonal differences were not statistically significant, anthropogenic mortality contributed proportionally more during summer months. Discussion – Our findings highlight terrestrial human-related pressures, particularly free-ranging dogs, as underrecognized mortality pathways in marine otters inhabiting human-dominated coastlines. Recurrent spatial clustering indicates predictable mortality risk hotspots and demonstrates the utility of spatio-temporal approaches for informing conservation and management strategies integrating terrestrial and marine systems. Copyright

Instituciones: Universidad Científica del Sur