Magnificent Maui: collaborations, cool whales and neat science

Written by Martin van Aswegen

Winter 2019 was a busy, but exciting time for the Marine Mammal Research Program (MMRP) humpback whale bioenergetics project. This collaborative project aims to quantify the bioenergetic demands of humpback whales migrating between the Alaskan foraging grounds and Hawaiian breeding grounds (for more info, please see the project page).

In January and March, Fabien, Dr. Andy Szabo (Alaska Whale Foundation; AWF) and Kelly Cates (University of Alaska Fairbanks; UAF) braved the cold to collect body condition and biopsy data of foraging humpback whales in southeast Alaska (see Fabien’s most recent blog here). Meanwhile in Maui, MMRP Director Dr. Lars Bejder and I conducted field trips in January and March. Both sampling trips took place within the Hawaiian Islands Humpback Whale National Marine Sanctuary, providing excellent opportunities to sample a high number of humpback whales early and late in the breeding season and across different age categories.

January: thank you Ultimate Whale Watch, OSI and ARL

In January, Lars and Josh Levy (Applied Research Laboratory at the University of Hawaiʻi at Manoa; ARL) conducted two weeks of fieldwork off Maui. With the generous support of Ultimate Whale Watch, Oceanwide Science Institute and ARL, the trip was very successful with 125 flights across eight days, totalling ~150 whales measured.

During the January expedition, a local tour operator notified us of a newborn calf. Once on scene, our UAV footage captured the floppy tail fluke and dorsal fin of the calf as well as the mother excreting blood postpartum (Fig. 1). Such an event is rare to witness as mothers typically distance themselves given the vulnerability of both mother and calf. You can see footage of the young calf in the video accompanying this blog.

Figure 1. Video still of the newborn calf recorded in January. Note the floppy tail flukes and dorsal fin of the calf and blood excreted by the mother.

March: thank you Pacific Whale Foundation

For two weeks in March, the Pacific Whale Foundation (PWF) partnered with us in field, led by Jens Currie and Stephanie Stack. The first week was dominated by persistent trade winds with choppy seas limiting our ability to sample. Fortunately, we were able to make use of the favourable conditions throughout the second week. In total, we flew 118 UAV flights over nine days with an additional ~150 humpback whales sampled, including calves, subadults and mature adults.

Dr. Adam Pack, Professor at University of Hawaiʻi at Hilo (UH Hilo) joined the PWF team and myself for three days of intensive tissue sampling. This represented the commencement of an exciting collaboration between Adam (UH Hilo), PWF, Dr. Shannon Atkinson (UAF), Dr. Kristi West (University of Hawaiʻi at Manoa) and MMRP. The aim is to utilize multiple data streams (UAV measurements, biopsy samples and photo-identification) to investigate possible links between humpback whale body condition, steroid hormones, lipid content and stable isotopes relative to demographics. Over the three-day period, the team managed to biopsy sample approximately 20 humpback whales where body condition measurements, biopsy samples and fluke IDs were all collected. This included adults and sub-adults from a variety of group compositions including single individuals, mother-calf-escort groups and competitive male groups.

Figure 2. Image of a successful biopsy sample taken by Dr. Adam Pack. Note the blubber/skin sample located in the tip of the biopsy dart.

Next steps

Like the whales, we are now shifting our focus back to the foraging grounds of southeast Alaska. I will be joining Andy and Kelly in early April for a two-week sampling trip, with the hope of measuring whales who have recently returned from the breeding grounds (or over-wintered in Alaska). Following our Spring fieldwork, we will commence a five-month Alaska summer season in May.

All research activities were conducted in accordance with NOAA permits 20311-01, 19703, 14585 and 19655. All UAV activities were conducted in accordance with FAA Part 107 regulations.

If you have any questions about this project, please contact:

Lars Bejder: lbejder@hawaii.edu

Martin van Aswegen: mvanaswegen@hotmail.com

Jens Currie: jenscurrie@pacificwhale.org

Stephanie Stack: stephaniestack@pacificwhale.org

Adam Pack: pack@hawaii.edu

Andy Szabo: info@alaskawhalefoundation.org