Risk of encounters between North Atlantic right whales and recreational vessel traffic in the southeastern United States.

Collisions with and disturbance from watercraft represent significant threats to endangered North Atlantic right whales (Eubalaena glacialis). Although several studies have investigated whale cooccurrence with commercial vessels, none has considered recreational vessels. We estimated an index between relative encounter risk of North Atlantic right whales and recreational vessel traffic in the southeastern USA calving grounds. Sightings of recreational vessels and right whales were recorded during aerial surveys in 2009-2014. We use generalized additive models to estimate relative occurrence of recreational vessels in the study area. We used estimates of relative North Atlantic right whale occurrence from Gowan and Ortega-Ortiz (2014). Results suggest that areas with elevated relative encounter risk were concentrated near navigable inlets. Additionally, temporal variability in these probabilities was influenced more by the spatial migratory patterns of North Atlantic right whales than by the distribution of recreational vessels. Our results can be used to inform the conservation of the North Atlantic right whales by identifying and mitigating areas with high risk of recreational vessel disturbance and collisions. [ABSTRACT FROM AUTHOR]