Using automated aerial imaging to estimate Arctic seal abundance: The devil is in the details

Recent reductions in Arctic summer sea ice extent have prompted increased interest in the status and trend of ice-associated seals.  We describe recently completed aerial surveys of four such species (bearded, ribbon, ringed, and spotted seals) in the Bering Sea, where a combination of automated digital photography and thermal imaging was used to count seals.  We highlight the numerous technical (e.g., data storage and processing) and statistical (e.g., incomplete detection, species misclassification) challenges that must be overcome to scale up from these raw data to comprehensive, reliable abundance estimates.