The role of behavioural variation in the success of artisanal fishers who interact with dolphins

Understanding the dynamics of small-scale fisheries requires considering the diversity of behaviours and skills of fishers. Fishers may have different abilities and tactics that can translate into different fishing outcomes. Here, we investigate variation in fishing behaviours among traditional net-casting fishers that are assisted by wild dolphins, and how this variation interacts with environmental conditions and influences fishing success. By combining in situ environmental sampling with fine-scale behavioural tracking from overhead videos, we found a higher probability of catching fish among fishers well-positioned in the water and that cast their nets wide-open and closer to dolphins. These differences in net-casting performance affect their chance of catching any fish over and above environmental conditions related to fish availability. This finding suggests that fishers' success may not be simply an outcome of variations in resource availability, but also result from subtle variations in fishing behaviours. We discuss how such behavioural variations can represent skills acquired over the years, and how such skills can be crucial for fishers to benefit and keep interacting with dolphins. Our study demonstrates the role of behavioural variation in the dynamics of a century-old fishery and highlights the need to consider fishers' behaviours in co-management of small-scale fisheries.