Pygmy blue whales seen on a 2018 survey, New Zealand

Between 28 January and 10 February 2018, the National Institute of Water and Atmospheric Research and collaborators conducted a voyage to attach satellite tracking devices to pygmy blue whales in the Taranaki region of New Zealand. The aim of this voyage was to examine the movement and habitat utilization of pygmy blue whales in New Zealand waters. This paper provides a summary of preliminary data collected during this research voyage. In total, we spent 72.51 hours (1637.54 km) actively searching for blue whales over eight survey days. Eleven blue whale sighting events were made (16 animals). Two blue whales were sighted twice, meaning that a total of 14 unique individuals were encountered. Other sightings included Bryde’s (possibly sei) whales, common dolphins, Hector’s dolphins, and fur seals. Two satellite tags were successfully deployed and six skin/blubber samples were collected from four blue whales. Photo-identification data were collected for eleven individual blue whales. Overall, blue whales were found further south, in lower numbers, and were not observed surface feeding, likely due to the La Niña anomalous oceanographic conditions. This resulted in warmer temperatures (4 - 6 °C higher than average climatology), reduced west wind flows, and consequent reduction in upwelling, significantly impacting the high productivity characteristic of the Taranaki region. All photo-identification data will be provided to a collaborative Southern Hemisphere Blue Whale Catalogue, supported by IWC and collaborations have been established with other researchers to share and compare data.