The U.S. National Oceanic and Atmospheric Administration (NOAA) released a report on 27 April indicating that U.S. Navy sonar transmissions may have played a role in the stranding of more than 150 melon-headed whales on 3 July 2004 off the coast of Kauai, Hawaii. At the time of the stranding, which resulted in one whale death, the Navy was preparing to conduct sonar activities as part of a military exercise.

The report notes that six naval surface vessels transiting to the area on the previous night intermittently transmitted mid-frequency active sonar. That activity is “a plausible, if not likely, contributing factor” to the stranding event. There was no significant weather, natural oceanographic event, or known biological factors that would explain the animals' movement into the bay nor the group's continued presence in the bay, according to report lead author Teri Rowles, NOAA marine mammal veterinarian.