by Rochelle Constantine, Associate Professor
School of Biological Sciences, University of Auckland
Auckland, New Zealand

27 July 2018, noon
Pauley Large Classroom, Hawaii Institute of Marine Biology
Hosted by HIMB Marine Mammal Research Program

ABSTRACT

Oceania Humpback Whales

Despite near extinction from commercial whaling, Oceania’s humpback whales are slowly recovering after 50 years of protection. We recently revealed the complex migration paths of these whales; showing different northern and southern pathways past NZ. Our multi-disciplinary approach using non-lethal research tools e.g., satellite telemetry, genetics, aging and hormone analysis, has given us a better understanding of these humpback whales spanning ~3,600km of Oceania and ~4,500km of Antarctic waters. There were differences in feeding ground based on reproductive status, and higher levels of pregnancy in females that is not matched by the slow increase in population size. This wide expanse of feeding grounds provides a challenge for future research, but is of interest given the changes in the Antarctic environment.

Bryde’s Whales and Ship-strike

The Hauraki Gulf, Auckland is the primary habitat for one of the world’s few year-round resident populations of Bryde’s whales. With ~150 whales, the population was vulnerable to ship-strike mortality as ships transited to New Zealand’s busiest port. From 1996-2014, an average of 2.3 whales/ annum were killed by ships. We used archival D-tags to understand the sub-surface behaviour and acoustic environment of Bryde’s whales to develop mitigation measures. We found whales have clear diel patterns with active days and resting at night. They spend 91% of their time near the sea-surface, increasing their strike risk. We ran a science informed social process with multiple stakeholders and within three years, ships voluntary slowed to ~10 knots leading to no whale deaths within the Gulf since late 2014. This is a rapid and rare positive conservation outcome in New Zealand.