Looking Back on Maui 2025: A Winter Full of Whales
- MMRP
- 2 days ago
- 11 min read
Written by Abigael Jacka, Taylor Rouse, and Lewis Evans
As we prepare for our 2026 humpback whale field season in Maui Nui, our team has taken a moment to look back on the incredible work accomplished last winter. Two of our 2024–2025 interns, Abigael Jacka and Taylor Rouse, recently compiled a detailed reflection on last year’s (2025) Maui field season — capturing the discoveries, day-to-day realities, and collaborative spirit that define our long-term research on humpback whales. Their account highlights both the science and the people behind this work.
About us
We are Abigael Jacka and Taylor Rouse, interns with the Marine Mammal Research Program (MMRP), based at the Hawaiʻi Institute of Marine Biology (HIMB), part of the University of Hawaiʻi at Mānoa. Over the past four years (Abigael) and one year (Taylor), we’ve had the incredible opportunity to contribute to MMRP’s research on humpback whales (HBWs). During the 2025 Maui field season, we joined PhD student Lewis Evans for his fieldwork in the waters of Maui, supporting a long-term project focused on whale health, behavior, and energetics.
What is our field season, and why do we do it?
The 2025 field season marked MMRP’s seventh field season monitoring HBWs in Hawaiʻi as part of our long-term monitoring effort to assess their health and better understand their life history. We were excited to return once again to the waters of Maui Nui, where most of Hawaiʻi’s humpbacks gather each winter. Every year, over 12,000 HBWs undertake an extraordinary migration (Up to a 10,000-mile round trip!) from their nutrient-rich feeding grounds to the warm waters of Hawaiʻi, putting our two trips bringing groceries into the house to shame! Maui Nui provides a shallow, sheltered region well-suited for mating, giving birth, and rearing newborn calves. While here, these whales fast, relying on energy reserves accumulated during the feeding season to fuel their energetically demanding reproductive activities.
As highlighted by the recent PhD work of MMRP post-doc Martin van Aswegen, mothers burn through energy fast, about 3,000 malasadas every day! (For more, see his blogs: Gestation Costs and Maternal Investment and calf growth.) As HBWs rely so heavily on stored energy to complete these essential life functions, disruptions to these budgets can impact their behavior, offspring viability, and survival. Understanding how HBWs manage their energy is key to anticipating how they’ll respond to environmental and human impacts. Long-term data provides the foundation to design conservation strategies, addressing current and future threats.
Our time in Maui Nui with the MMRP was spent making crucial observations and collecting data that will help better understand their bioenergetics, mating behaviors, and overall health. Using drones, photo-ID, blow sampling, biopsy sampling, and non-invasive biologging tags, we have started to uncover the mysteries of what it costs to be a HBW.
Why might we care what it takes to be a whale?
Well, HBWs play a vital role in the marine ecosystem. As apex predators, they help manage marine populations, transport nutrients, and store carbon, making them key players in ocean health. In Hawaiʻi, koholā also hold deep cultural significance, including their role as ʻaumākua and embodiments of Kanaloa. They also support a thriving whale-watching industry that benefits local coastal communities. By better understanding their behavior, biology, and habitat needs, we aim to protect their future and, in turn, our own.
2025 Maui field season: On-The-Water Conditions
Last season brought an unexpected weather phenomenon, making sighting marine mammals a bit tricky. During our three months on the water, Hawaiʻi’s shield volcano Kīlauea erupted a total of 12 times. Vog, or volcanic fog, swept in from the Big Island of Hawaiʻi when the winds prevailed from the south or southeast instead of our normal northwestern trades.
Speaking of trade winds, Maui is known as the Valley Isle, and when the trade winds pick up, they funnel through the valley between Mauna Kahalawai and Haleakala, often blowing 20 to 30 knots in the afternoon! This can make getting a clear body condition photo difficult due to water distortion, so we woke up with the sun and did our best to beat the wind. We were able to spend 534 hours on the water, often finding calm water on the southwest shore, using Mauna Kahalawai for shelter.
A season defined by great collaborations
Our season really began in mid-December when Lewis and Tay joined the Pacific Whale Foundation for a week on their research vessel, Kaiao. The goal was to capture the early arrival of male humpback whales on the breeding grounds, a critical window, as males typically arrive before other demographics and are notoriously difficult to re-encounter later in the season. By documenting these early arrivals, we increased our chances of tracking individual males throughout the following months. Despite poor weather, we managed one memorable day on the water, where we encountered none other than Captain Hook, one of the most iconic humpbacks in our dataset. A renowned bubble-net feeder from Southeast Alaska, he’s an individual we’ve tracked and sampled over multiple years across both his feeding and breeding grounds. The same day, we were called to assist, alongside NOAA’s team, with a difficult disentanglement of a HBW in the Pailolo Channel between Kā‘anapali and the south shore of Moloka‘i. These few days set the stage for an incredibly collaborative field season.
You might want to take a seat to hear about last season’s stats, as it was one of our most successful seasons yet! Over the course of our three-month research season, we collected 1,802 HBW body condition measurements and 813 linked fluke-IDs, making it our second-largest year, following 2023.
We were also very fortunate to welcome some special collaborators last season who introduced us to new sampling techniques and data collection methods. During mid-February, we had the pleasure of hosting Colin Perkins-Taylor and his “Snot Bot” from NOAA. Colin collaborated with us to help Nelmarie Giovannetti from the UH Health and Stranding Lab on her project aimed at detecting morbillivirus in free-ranging cetaceans. Together, they helped us refine and implement a method for collecting blow samples non-invasively from HBWs. With Colin's expertise, we successfully collected 20 blow samples from individuals of different age classes. We are excited to see what the data shows and how this project develops.
We also collected 80 biological samples – blubber/skin biopsies, from 79 adult females with calves. These biopsies will be used for hormone analysis to better understand postpartum ovulation in mothers, providing key insights into the ability for global HBW populations to recover.
Two weeks out of every season, we have the privilege of working alongside the MMRP tag team (Lars Bejder, William Gough, Gussie Hollers, and Cameron Nemeth), and last season was no exception. During this time, we shift our focus to tagging HBWs and linking them with body condition measurements, biopsies, and blow samples! This gives us a complete biological and physical profile for individual whales. Last season, we also collaborated with researchers Dr. Angelo Torrente (Institute of Functional Genomics, University of Montpellier) and Dr. Andres Fahlman (Global Diving Research SL) to refine methods for deploying heart rate tags on HBWs.
With hundreds of tourists, tour operators, and researchers watching the water throughout the season, not all experiences are lighthearted. We spent many hours aiding NOAA’s disentanglement team, which responded to over 16 entangled whales, their highest number in 23 years. When we got the call, dropping all other plans for the day was a given.
First spotted on 26th of January with a loop through her mouth and trailing over 150 feet of line, one HBW taught us perseverance as her small light gray calf swam alongside her. We were able to fly our drone for a better look at the entanglement, giving NOAA’s team a “bird’s eye view” to better assess the situation, for which they successfully cut the loop. As she swam further into open water, we all held our breaths, hoping the intervention would be enough for her to eventually let go of the line. Exactly 29 days later, we spotted the mother and her scratched-up calf again. Though still trailing the line from her mouth, it was significantly shorter on the side where NOAA’s team made their cut. Hopefully, the line continued to slip out, and the mom and calf had an easy migration back to their feeding grounds for the summer. Encounters like these are the reason we spend months on the water and even more so in the lab! Data on the body condition of cetaceans affected by entanglements and other anthropogenic stressors provides valuable insights into their response to disturbance, information that can inform local management and response strategies.
Season highlights
Stepping off the boat after such a busy season, we can’t help but feel grateful for the opportunities that Maui has provided us. Regardless of the weather, these blue spaces, along with the communities and wildlife that depend on them, continue to inspire us. With projects focusing on energy expenditure and mate selection, the work has just begun for our graduate students and interns. Looking back on this season, I think we can all agree that every day on the water was a good day. However, some days felt just a little extra special alongside these ocean giants.
March 28th, 2025, pt. 1 – During an early morning encounter on our 2nd to last day, just around McGregor Point, we spotted a very splashy juvenile. As we got closer, we realized this juvenile was anything but alone, accompanied by roughly 8 bottlenose dolphins. We have seen many interspecies encounters this season, but this was definitely one for the books. As these dolphins approached our boat, hoping for a fun bow ride, the juvenile whale seemed to feel betrayed by its smaller travel companions. Anytime the dolphins came up close to the boat, the juvenile whale would swoop in and push them away with tail swipes and pec slaps. It is always a treat to see how species interact, especially when it appears to be in a playful manner. It serves as a reminder that these creatures form complex connections just as we humans do.
March 28th, 2025, pt. 2 –As we neared the middle of our day, we had PhD student Gussie prepare the suction cup tags, hoping to find the perfect end-of-season comp group to tag. We crossed our fingers, sent all our good vibes into the ocean, and offered a quick prayer to the whale gods for something good. With a 360-degree boat watch underway, we observed and waited, and suddenly we heard Tay yell, “SPLASHY WHALES 11 O’CLOCK.” You can only imagine the excitement on the boat as we approached, and we saw blow after blow after blow. With Gussie's help, we successfully tagged four escorts in this comp group, gaining insight into late-season comp group dynamics and energetics. Since this was our second-to-last day on the water, we decided to stick with them, ensuring we could retrieve any tags that were inevitably knocked off and allowing us ample time to collect drone footage. By the end of the day, we had spent almost four hours witnessing the sheer power and stamina of these HBWs.
We were able to get two tags back that same day, allowing us to view the tag footage later that night. Nothing could have prepared us to see this footage; it left us again in a state of awe. One of the tags was bumped by another whale and slid sideways, giving us a nice view to the right of the tagged whale. All we could see were layers of whales, some close, some in the distance, all swimming and competing with one another. It was a jaw-dropping HBW tag watch party as we all sat outside on the deck, screeching with excitement. Moments like this make all the long nights, days, weeks, and months of the field season so worthwhile and remind us why we are here, fighting to protect and better understand these amazing creatures.
Acknowledgments
We want to acknowledge the significance of koholā (humpback whale) within Hawaiian culture as ʻaumākua and manifestations of Kanaloa. We use minimally invasive techniques and undergo a rigorous permitting process to interact with whales. We are very grateful to be able to study them and contribute to their conservation and protection.
We would like to extend a special mahalo to the Pacific Whale Foundation for their continued and generous support of this project. Their assistance was instrumental in facilitating our pilot field season in December, running additional field days on our behalf, and providing unwavering support throughout. This season would not have been as successful without their dedication. Thank you, Jens Currie, Shannon Barber-Meyer, Grace Olson, Brian Stirling, and Florence Sullivan.
We are grateful for the cooperative nature and support from the Maui community. Tour companies, Pac Whale eco-tours, Ocean Adventures Maui, and Sail Maui directed us to humpbacks, facilitating our research. A big mahalo to other research groups for their cooperation and dedication to humpback whale research, such as Whale Trust, Keiki Koholā Project, and the Hawaiian Islands Humpback Whale National Marine Sanctuary.
This project was made possible through the efforts of many passionate and hardworking individuals. We are deeply grateful to the following people for their time, cooperation, logistical support, and generosity: Paul Schofield, Steph Vlachos, Karen Harper, Poalo Marra-Biggs, Jason Jones, Robert Hollifield, Robert Abrew, Jonny Pinder, Ed Lyman, Marc Lammers, Maria Harvey, Stephanie Stack, Isabel Gutowski, Teo Lorenzo, Alyssa Perez, Chloe Houy, Soleil von Hausch, Jessa Price, Kiana Cadavona, Liah McPherson, Elizabeth Beato, Caroline Smith, Vaun Stover-French, Martin van Aswegen, and Kyleigh Fertitta.
We are extremely grateful for our funders, whose support truly makes this work possible. Their contributions allow us to get out on the water and collect the critical scientific data that managers rely on to keep humpback whales protected at local, national, and international levels. This support also helps us learn more about these incredible animals every season — how they behave, how they change over time, and how they respond to our shifting oceans. Just as importantly, it allows us to share what we learn with our community, from creating outreach materials for schools to engaging with people who are just as excited about whales as we are. Mahalo to the Living Marine Resources (LMR) program, the Office of Naval Research (ONR), and DoD’s Defense University Research Instrumentation Program, United States Pacific Fleet Environmental Readiness Division and Dolphin Quest. We are grateful to philanthropic donations made by JP and Dalia Maheu, Denise O'Leary and Kent Thiry, Benjy Garfinkle, Brion Applegate, Kristin and Larry Link, Brook Byers, Paul and Elle Stephens, Barbara and Duncan Chapman, Peter Beck, Benjy Garfinkle, Thomas Griggs, and Schwab Foundation. We thank Young Brothers for welcoming us into their Community Shipping Program and for providing essential logistical support in transporting our research vessel. Our field seasons would not have been possible without your support.
All research was conducted under NMFS permit #27548 and with IACUC approval.
If you would like to read more about previous seasons and watch cool videos from the field, please visit the following blogs!
2024 season recap: Island hopping: a three-month field season off Hawai’i Island
2023 season recap: Maui 2023 humpback whale field season review
2022 season recap: 2022 Maui Fieldwork Update: good weather, lots of whales and a few surprise disentanglements!
If you’d like to support our research, please click the blue whale below — any donation, big or small, makes a meaningful difference in helping us protect these incredible animals. Mahalo for being part of this work!
