A Visual Sighting and Acoustic Detections of Minke Whales, Balaenoptera acutorostrata (Cetacea: Balaenopteridae), in Nearshore Hawaiian Waters

Minke whales, Balaenoptera acutorostrata (Lacépède), have been considered a rare species in Hawaiian waters due to limited sightings during visual and aerial surveys. However, our research suggests that they are more common than previously considered. In spring 2005, a combined visual-acoustic survey of cetaceans in Hawaiian waters resulted in the sighting of a minke whale within 22 km of Kaua‘i. Minke whale vocalizations were also detected at several other locations near Kaua‘i and O‘ahu. These 2005 reports are the first from nearshore (< 50 km) Hawaiian waters despite years of previous shipboard and aerial surveys. The lack of historical sightings is likely due to misidentification or the inability to detect these animals during poor sighting conditions. We recommend that future cetacean surveys in Hawaiian waters include a passive acoustic component to increase the likelihood of detecting minke whales.