Chesapeake DolphinWatch weekly data

Bottlenose dolphins (Tursiops truncatus) are migratory marine mammals that live in both open-ocean and coastal habitats. Although widely studied, little is known about their occurrence patterns in the highly urbanized Chesapeake Bay, U.S.A. The goal of this study was to establish the spatial and temporal distribution of bottlenose dolphins throughout this large estuarine system and use statistical modeling techniques to determine how their distribution relates to environmental factors. Three years (2017-2019) of observational dolphin sighting reports from a citizen-science database, Chesapeake DolphinWatch, were used to determine relative occurrence throughout the estuary. The dolphins had a distinct temporal pattern, most commonly sighted during summer months with a peak in July. This pattern of observed occurrence was confirmed with passive acoustic detections of dolphin echolocation clicks. Using a Generalized Additive Model (GAM), dolphin presence was found to be significantly corre...