Novel prey item identified for estuarine bottlenose dolphins (Tursiops erebennus) in the Southeastern United States

The community of Tamanend’s bottlenose dolphins (Tursiops erebennus) inhabiting the St. Johns River (SJR) in Jacksonville, Florida, is affected by a suite of challenges including dredging, vessel traffic, fishing gear entanglements, pollution, and natural disturbances. Despite regular observations of foraging during photo-identification surveys, this study is the first to identify SJR dolphin prey. We describe species composition, size, and relative proportions of prey found in the stomachs of dead dolphins that stranded in the SJR (n = 10) and were the first to document violet goby (Gobioides broussonnetii) as bottlenose dolphin prey. These findings provide a baseline understanding of SJR dolphin foraging ecology. Details provided in this study will assist in the identification of violet goby consumption, should it occur within other dolphin communities. Prey identification within a vital dolphin habitat can inform ecosystem-based management decisions that will preserve the St. Johns River estuary. By identifying a previously undetected prey item, this study also expands knowledge of potential bottlenose dolphin prey on the Atlantic coast of the United States.