“Nacho”—A willing and adventurous dolphin with diverse research accomplishments

Abstract

The bottlenose dolphin, WEN (also known as “Nacho”), worked in the swimmer interdiction system of the United States Navy Marine Mammal Program (MMP) before being transferred to MMP research in the mid-2000s. During his time away from systems work, WEN participated in diverse research projects that benefited our understanding of dolphin hearing, bioacoustics, and auditory physiology. His contributions include several ground-breaking studies: (1) he demonstrated that dolphins could remain vigilant at an acoustic target detection task for days without rest or performance decrement, (2) participated in the first study matching dolphin structural (MRI) and functional imaging (SPECT, PET) with an emphasis on the anatomy of sound-reception and transmission, (3) performed open-ocean work to investigate the target strength of dolphins at depth and the potential for intravascular bubble formation during diving, (4) was instrumental in the development of auditory evoked potential (AEP) methods for use in MMP dolphins, and (5) performed the first direct comparison of AEP and behavioral thresholds to the same acoustic stimulus in a marine mammal. Not only have WEN’s contributions significantly advanced marine mammal science, but with his return to systems work, he continues to contribute to the national security of the United States.