The science your ticket helps make possible
For years, our boats and crew have carried marine scientists to the whales and reefs of Maui — donating vessel time, logistics, and hands in the field. Here is the peer-reviewed research that work has helped support.
Every study below names Ultimate Whale Watch & Snorkel or our captains and crew in print. We helped make the fieldwork happen, and the researchers gave us a shout out in their final publications!
- 2026
Gaping in humpback whales: a rarely seen behavior, caught by citizen science
Whale-watch and social-media footage — including from Maui — was used to document “gaping,” an unusual open-mouth behavior scientists seldom get to see.Our role: We contributed whale-watch observation footage used in the study.Pirotta, V., Taylor, I. A. R., Harcourt, R., & Reidenberg, J. S. (2026). Gaping in Humpback Whales, A Unique Behavior Documented Through Citizen Science. Animal Behavior and Cognition, 13(2), 153–164. https://doi.org/10.26451/abc.13.02.03.2026https://doi.org/10.26451/abc.13.02.03.2026(opens in a new tab) - 2025
Aerial photo-ID improves how reliably individual humpbacks are re-sighted
Drone photos were shown to identify individual whales more dependably than traditional tail-fluke photos, strengthening long-term monitoring.Our role: We gave logistical support for the aerial photo-ID fieldwork.Evans, L. I., van Aswegen, M., Feinberg, S., Currie, J. J., Stack, S. H., Szabo, A., & Bejder, L. (2025). Elevating Photo-Identification: Aerial-Identification Improves Re-Sight Rates and Supports Long-Term Monitoring of Humpback Whales. Marine Mammal Science, 42(1), e70078. https://doi.org/10.1111/mms.70078https://doi.org/10.1111/mms.70078(opens in a new tab) - 2025
How much mothers invest in their calves across the Maui season
Using drone photogrammetry, researchers measured how much body condition humpback mothers pour into their growing calves while in Hawaiian waters.Our role: We provided field support for the drone photogrammetry work.van Aswegen, M., Szabo, A., Currie, J. J., Stack, S. H., Evans, L., Straley, J., Neilson, J., Gabriele, C., Cates, K., Steel, D., & Bejder, L. (2025). Maternal investment, body condition and calf growth in humpback whales. The Journal of Physiology, 603(2), 551–578. https://doi.org/10.1113/JP287379https://doi.org/10.1113/JP287379(opens in a new tab) - 2025
Body length, mass, and the energy cost of growing up as a humpback
Estimated how humpback whale size and the energy needed to grow change at each life stage — foundational numbers for understanding the species.Our role: We provided field support for the drone photogrammetry work.van Aswegen, M., Szabo, A., Currie, J. J., Stack, S. H., Straley, J., Neilson, J., Gabriele, C., Cates, K., Baker, C. S., Steel, D., Pack, A. A., West, K. L., Hofmann, N. J., Toonen, R. J., Loockerman, C., Sullivan, F. A., Cheeseman, T., Sharpe, F., & Bejder, L. (2025). Age-specific body length, mass, and energetic cost of growth in humpback whales. Marine Ecology Progress Series, 770, 171–194. https://doi.org/10.3354/meps14937https://doi.org/10.3354/meps14937(opens in a new tab) - 2025
Humpbacks tending to injured companions during entanglement rescues
Documented rare “helping” behavior — whales attending to entangled companions — observed during disentanglement events off Maui.Our role: Our response vessel Aloha Kai and crew supported the disentanglement effort.Cartwright, R., Lyman, E., Venema, A., Currie, J. J., Stack, S. H., Pack, A. A., Bejder, L., van Aswegen, M., Wright, S. K., & Horn, D. (2025). Tending the sick: Observations of epimeletic behavior in humpback whales towards conspecifics during entanglement events. PLOS ONE, 20(4), e0321284. https://doi.org/10.1371/journal.pone.0321284https://doi.org/10.1371/journal.pone.0321284(opens in a new tab) - 2024
When humpbacks sing: singing patterns by time of day off Maui
Mapped how male humpback singing rises and falls through the day across one of the densest breeding grounds in the world.Our role: We gave in-kind support and crew volunteered on recorder deployments.Kügler, A., Lammers, M. O., Pack, A. A., Tenorio-Hallé, L., & Thode, A. M. (2024). Diel spatio-temporal patterns of humpback whale singing on a high-density breeding ground. Royal Society Open Science, 11(1), 230279. https://doi.org/10.1098/rsos.230279https://doi.org/10.1098/rsos.230279(opens in a new tab) - 2024
Corals that survive repeated heat stress show signs of adapting
Found that corals living through repeated Maui bleaching events show signs of natural selection and acclimatization — a hopeful signal for reef resilience.Our role: We provided vessels and local field support for the reef surveys.McCarthy, O. S., Winston Pomeroy, M., & Smith, J. E. (2024). Corals that survive repeated thermal stress show signs of selection and acclimatization. PLOS ONE, 19(7), e0303779. https://doi.org/10.1371/journal.pone.0303779https://doi.org/10.1371/journal.pone.0303779(opens in a new tab) - 2022
Tracking several singing humpbacks at once with underwater sensors
Developed a method to pinpoint and follow multiple singing humpback whales simultaneously using directional underwater sensors off Maui.Our role: Our vessels and crew supported deployment and recovery of the instruments.Tenorio-Hallé, L., Thode, A. M., Lammers, M. O., Conrad, A. S., & Kim, K. H. (2022). Multi-target 2D tracking method for singing humpback whales using vector sensors. The Journal of the Acoustical Society of America, 151(1), 126-137. https://doi.org/10.1121/10.0009165https://doi.org/10.1121/10.0009165(opens in a new tab) - 2022
What humpback birth and escorting behavior actually look like
Pulled together nine documented humpback births worldwide — including one witnessed off Maui — to describe birth and the escorting behavior around it.Our role: Two of our crew are named as authors, with Ultimate Whale Watch listed as their affiliation.Ransome, N., Bejder, L., Jenner, M., Penfold, G., Brosig, V. J., Kitson, C., Skjothaug, R., Neilson, E., Loneragan, N. R., & Smith, J. N. (2022). Observations of parturition in humpback whales (Megaptera novaeangliae) and occurrence of escorting and competitive behavior around birthing females. Marine Mammal Science, 38(2), 408–432. https://doi.org/10.1111/mms.12864https://doi.org/10.1111/mms.12864(opens in a new tab) - 2021
Whale song loudness tracks how many whales are really there
Showed that the volume of male humpback “chorusing” is a reliable stand-in for how many whales are present — a cheaper way to monitor the population.Our role: We gave in-kind support and crew volunteered on deployments.Kügler, A., Lammers, M. O., Zang, E. J., & Pack, A. A. (2021). Male Humpback Whale Chorusing in Hawai'i and Its Relationship With Whale Abundance and Density. Frontiers in Marine Science, 8, 735664. https://doi.org/10.3389/fmars.2021.735664https://doi.org/10.3389/fmars.2021.735664(opens in a new tab) - 2020
Listening to the drop in Maui’s humpback numbers after 2015
Used years of underwater song recordings off Maui to track the sharp decline in humpback whale numbers that began around 2015.Our role: We donated vessel and crew time to service the acoustic recorders.Kügler, A., Lammers, M. O., Zang, E. J., Kaplan, M. B., & Mooney, T. A. (2020). Fluctuations in Hawaii's humpback whale population inferred from male song chorusing off Maui. Endangered Species Research, 43, 421–434. https://doi.org/10.3354/esr01080https://doi.org/10.3354/esr01080(opens in a new tab) - 2019
Why Hawaii’s humpback calf numbers swing year to year
Linked year-to-year swings in Hawaiian humpback reproduction to climate anomalies in the North Pacific that ripple up the food chain.Our role: We provided vessel time and logistics for the field team.Cartwright, R., Venema, A., Hernandez, V., Wyels, C., Cesere, J., & Cesere, D. (2019). Fluctuating reproductive rates in Hawaii's humpback whales reflect recent climate anomalies in the North Pacific. Royal Society Open Science, 6(3), 181463. https://doi.org/10.1098/rsos.181463https://doi.org/10.1098/rsos.181463(opens in a new tab) - 2018
The sound of a coral reef reflects the life on it
Linked the underwater soundscape of Maui reefs to fish abundance and coral cover — and picked up humpback song rolling in each winter.Our role: We provided vessel support for the reef recordings.Kaplan, M. B., Lammers, M. O., Zang, E., & Mooney, T. A. (2018). Acoustic and biological trends on coral reefs off Maui, Hawaii. Coral Reefs, 37(1), 121–133. https://doi.org/10.1007/s00338-017-1638-xhttps://doi.org/10.1007/s00338-017-1638-x(opens in a new tab) - 2012
Where mother-calf humpback pairs choose to rest in the Au’au Channel
Found that humpback mothers with calves favor deeper mid-channel water off Maui, not the shallow nearshore — reshaping how we think about their habitat.Our role: We gave in-kind support and vessel time during the 2009 season.Cartwright, R., Gillespie, B., LaBonte, K., Mangold, T., Venema, A., Eden, K., & Sullivan, M. (2012). Between a Rock and a Hard Place: Habitat Selection in Female-Calf Humpback Whale Pairs on the Hawaiian Breeding Grounds. PLoS ONE, 7(5), e38004. https://doi.org/10.1371/journal.pone.0038004https://doi.org/10.1371/journal.pone.0038004(opens in a new tab)
- 2024
When humpbacks sing: singing patterns by time of day off Maui
Mapped how male humpback singing rises and falls through the day across one of the densest breeding grounds in the world.Our role: We gave in-kind support and crew volunteered on recorder deployments.Kügler, A., Lammers, M. O., Pack, A. A., Tenorio-Hallé, L., & Thode, A. M. (2024). Diel spatio-temporal patterns of humpback whale singing on a high-density breeding ground. Royal Society Open Science, 11(1), 230279. https://doi.org/10.1098/rsos.230279https://doi.org/10.1098/rsos.230279(opens in a new tab) - 2022
Tracking several singing humpbacks at once with underwater sensors
Developed a method to pinpoint and follow multiple singing humpback whales simultaneously using directional underwater sensors off Maui.Our role: Our vessels and crew supported deployment and recovery of the instruments.Tenorio-Hallé, L., Thode, A. M., Lammers, M. O., Conrad, A. S., & Kim, K. H. (2022). Multi-target 2D tracking method for singing humpback whales using vector sensors. The Journal of the Acoustical Society of America, 151(1), 126-137. https://doi.org/10.1121/10.0009165https://doi.org/10.1121/10.0009165(opens in a new tab) - 2021
Whale song loudness tracks how many whales are really there
Showed that the volume of male humpback “chorusing” is a reliable stand-in for how many whales are present — a cheaper way to monitor the population.Our role: We gave in-kind support and crew volunteered on deployments.Kügler, A., Lammers, M. O., Zang, E. J., & Pack, A. A. (2021). Male Humpback Whale Chorusing in Hawai'i and Its Relationship With Whale Abundance and Density. Frontiers in Marine Science, 8, 735664. https://doi.org/10.3389/fmars.2021.735664https://doi.org/10.3389/fmars.2021.735664(opens in a new tab) - 2020
Listening to the drop in Maui’s humpback numbers after 2015
Used years of underwater song recordings off Maui to track the sharp decline in humpback whale numbers that began around 2015.Our role: We donated vessel and crew time to service the acoustic recorders.Kügler, A., Lammers, M. O., Zang, E. J., Kaplan, M. B., & Mooney, T. A. (2020). Fluctuations in Hawaii's humpback whale population inferred from male song chorusing off Maui. Endangered Species Research, 43, 421–434. https://doi.org/10.3354/esr01080https://doi.org/10.3354/esr01080(opens in a new tab)
- 2026
Gaping in humpback whales: a rarely seen behavior, caught by citizen science
Whale-watch and social-media footage — including from Maui — was used to document “gaping,” an unusual open-mouth behavior scientists seldom get to see.Our role: We contributed whale-watch observation footage used in the study.Pirotta, V., Taylor, I. A. R., Harcourt, R., & Reidenberg, J. S. (2026). Gaping in Humpback Whales, A Unique Behavior Documented Through Citizen Science. Animal Behavior and Cognition, 13(2), 153–164. https://doi.org/10.26451/abc.13.02.03.2026https://doi.org/10.26451/abc.13.02.03.2026(opens in a new tab) - 2022
What humpback birth and escorting behavior actually look like
Pulled together nine documented humpback births worldwide — including one witnessed off Maui — to describe birth and the escorting behavior around it.Our role: Two of our crew are named as authors, with Ultimate Whale Watch listed as their affiliation.Ransome, N., Bejder, L., Jenner, M., Penfold, G., Brosig, V. J., Kitson, C., Skjothaug, R., Neilson, E., Loneragan, N. R., & Smith, J. N. (2022). Observations of parturition in humpback whales (Megaptera novaeangliae) and occurrence of escorting and competitive behavior around birthing females. Marine Mammal Science, 38(2), 408–432. https://doi.org/10.1111/mms.12864https://doi.org/10.1111/mms.12864(opens in a new tab) - 2012
Where mother-calf humpback pairs choose to rest in the Au’au Channel
Found that humpback mothers with calves favor deeper mid-channel water off Maui, not the shallow nearshore — reshaping how we think about their habitat.Our role: We gave in-kind support and vessel time during the 2009 season.Cartwright, R., Gillespie, B., LaBonte, K., Mangold, T., Venema, A., Eden, K., & Sullivan, M. (2012). Between a Rock and a Hard Place: Habitat Selection in Female-Calf Humpback Whale Pairs on the Hawaiian Breeding Grounds. PLoS ONE, 7(5), e38004. https://doi.org/10.1371/journal.pone.0038004https://doi.org/10.1371/journal.pone.0038004(opens in a new tab)
- 2025
Aerial photo-ID improves how reliably individual humpbacks are re-sighted
Drone photos were shown to identify individual whales more dependably than traditional tail-fluke photos, strengthening long-term monitoring.Our role: We gave logistical support for the aerial photo-ID fieldwork.Evans, L. I., van Aswegen, M., Feinberg, S., Currie, J. J., Stack, S. H., Szabo, A., & Bejder, L. (2025). Elevating Photo-Identification: Aerial-Identification Improves Re-Sight Rates and Supports Long-Term Monitoring of Humpback Whales. Marine Mammal Science, 42(1), e70078. https://doi.org/10.1111/mms.70078https://doi.org/10.1111/mms.70078(opens in a new tab) - 2019
Why Hawaii’s humpback calf numbers swing year to year
Linked year-to-year swings in Hawaiian humpback reproduction to climate anomalies in the North Pacific that ripple up the food chain.Our role: We provided vessel time and logistics for the field team.Cartwright, R., Venema, A., Hernandez, V., Wyels, C., Cesere, J., & Cesere, D. (2019). Fluctuating reproductive rates in Hawaii's humpback whales reflect recent climate anomalies in the North Pacific. Royal Society Open Science, 6(3), 181463. https://doi.org/10.1098/rsos.181463https://doi.org/10.1098/rsos.181463(opens in a new tab)
- 2025
How much mothers invest in their calves across the Maui season
Using drone photogrammetry, researchers measured how much body condition humpback mothers pour into their growing calves while in Hawaiian waters.Our role: We provided field support for the drone photogrammetry work.van Aswegen, M., Szabo, A., Currie, J. J., Stack, S. H., Evans, L., Straley, J., Neilson, J., Gabriele, C., Cates, K., Steel, D., & Bejder, L. (2025). Maternal investment, body condition and calf growth in humpback whales. The Journal of Physiology, 603(2), 551–578. https://doi.org/10.1113/JP287379https://doi.org/10.1113/JP287379(opens in a new tab) - 2025
Body length, mass, and the energy cost of growing up as a humpback
Estimated how humpback whale size and the energy needed to grow change at each life stage — foundational numbers for understanding the species.Our role: We provided field support for the drone photogrammetry work.van Aswegen, M., Szabo, A., Currie, J. J., Stack, S. H., Straley, J., Neilson, J., Gabriele, C., Cates, K., Baker, C. S., Steel, D., Pack, A. A., West, K. L., Hofmann, N. J., Toonen, R. J., Loockerman, C., Sullivan, F. A., Cheeseman, T., Sharpe, F., & Bejder, L. (2025). Age-specific body length, mass, and energetic cost of growth in humpback whales. Marine Ecology Progress Series, 770, 171–194. https://doi.org/10.3354/meps14937https://doi.org/10.3354/meps14937(opens in a new tab) - 2025
Humpbacks tending to injured companions during entanglement rescues
Documented rare “helping” behavior — whales attending to entangled companions — observed during disentanglement events off Maui.Our role: Our response vessel Aloha Kai and crew supported the disentanglement effort.Cartwright, R., Lyman, E., Venema, A., Currie, J. J., Stack, S. H., Pack, A. A., Bejder, L., van Aswegen, M., Wright, S. K., & Horn, D. (2025). Tending the sick: Observations of epimeletic behavior in humpback whales towards conspecifics during entanglement events. PLOS ONE, 20(4), e0321284. https://doi.org/10.1371/journal.pone.0321284https://doi.org/10.1371/journal.pone.0321284(opens in a new tab)
- 2024
Corals that survive repeated heat stress show signs of adapting
Found that corals living through repeated Maui bleaching events show signs of natural selection and acclimatization — a hopeful signal for reef resilience.Our role: We provided vessels and local field support for the reef surveys.McCarthy, O. S., Winston Pomeroy, M., & Smith, J. E. (2024). Corals that survive repeated thermal stress show signs of selection and acclimatization. PLOS ONE, 19(7), e0303779. https://doi.org/10.1371/journal.pone.0303779https://doi.org/10.1371/journal.pone.0303779(opens in a new tab) - 2018
The sound of a coral reef reflects the life on it
Linked the underwater soundscape of Maui reefs to fish abundance and coral cover — and picked up humpback song rolling in each winter.Our role: We provided vessel support for the reef recordings.Kaplan, M. B., Lammers, M. O., Zang, E., & Mooney, T. A. (2018). Acoustic and biological trends on coral reefs off Maui, Hawaii. Coral Reefs, 37(1), 121–133. https://doi.org/10.1007/s00338-017-1638-xhttps://doi.org/10.1007/s00338-017-1638-x(opens in a new tab)