Shared Waters, Divided Interests: A Systematic Review of Human–Otter Conflicts Worldwide

Abstract

Introduction

Human–wildlife conflicts are rising due to encroachment of human activities into natural areas. While research has often focused on large mammals, negative interactions with small carnivores remain less documented. Among these, otters (Lutrinae), apex predators of freshwater and marine habitats, cause frequent competing interactions with human activities like angling and fish-farming.

Aims

We aimed to identify which otter species are most commonly involved in human–wildlife conflicts, characterise the types of conflict and explore their geographical and temporal patterns.

Methods

We conducted a systematic review of peer-reviewed literature following PRISMA guidelines. From 81 eligible studies reporting empirical cases of otter–human conflicts, we extracted data on species, conflict type and location. A Generalised Mixed-Effects Model was applied to assess temporal trends and the role of human population growth, while accounting for variation in research effort.

Results

Conflicts were documented for all otter species except the Congo clawless otter (Aonyx congicus). The Eurasian (Lutra lutra) and smooth-coated otter (Lutrogale perspicillata) dominated conflict-related records. Fisheries-related issues, such as damage to nets and depredation of fish, were the most frequently reported (n = 76), whereas direct attacks on humans were newly documented but rare (n = 16). Overall, conflicts increased over time and were positively associated with human population size across otter distributions.

Conclusions

Human–otter conflicts are a growing conservation concern. Effective mitigation measures include deterrents, protective fencing, adjustments in fishing practices, financial compensation and interventions addressing human attitudes. Solutions should be tailored to the conflict source and cultural context to foster coexistence and support long-term otter conservation.