Accurately estimating spatiotemporal variation in the abundance and density of marine animals, as well as directly observing behaviors, is crucial for answering many basic questions about their biology and ecology. It is also critical for assessing their ecological importance in marine ecosystems and evaluating the impact of human activities on populations (e.g., shing, habitat modication, behavioral disturbance, climate change). Yet, it can be extremely challenging to estimate abundances and densities and observe the natural behavior of many taxa, including elasmobranchs.