Marine Mammal Program
The Marine Mammal Program studies the distribution, abundance, behavior, and health of marine mammals to support their conservation and management. We combine field surveys and quantitative methods, including distance sampling, mark-recapture, and density surface modeling, with satellite- and drone-based remote sensing and machine learning, to estimate where and when animals occur, how many there are, and how human activities affect them. Our work spans cetaceans and pinnipeds, including beluga, bowhead, and humpback whales, harbor porpoises, harbor and gray seals, and Antarctic pack-ice seals such as the Weddell seal.
Program Directors: Megan Ferguson, Ph.D.; Michael Wethington, Ph.D.
Contributing Staff: Merra Howe, M.S.; Jeff Morris, Ph.D.
Capabilities
We combine field and remote-sensing methods with quantitative modeling to: advance our understanding of marine mammal ecology; estimate marine mammal abundance, distribution, and population status; and evaluate or predict impacts of human activities on marine mammals
Contaminant and health assessment: evaluation of contaminant burdens and health indicators in marine mammals, in collaboration with BRI’s Toxicology Lab.
Featured Projects
Beluga density and abundance modeling
The Program developed spatially explicit models of beluga (Delphinapterus leucas) density in Norton Sound and near the Yukon River delta from aerial line-transect survey data. These models improved the precision and spatial resolution of abundance estimates for the Eastern Bering Sea beluga whale stock. This work anchors the Program’s use of distance sampling, mark-recapture, and density surface modeling.
Gray seal detection from satellite imagery
In collaboration with NOAA’s Northeast Fisheries Science Center, the Program is developing an automated pipeline that detects and counts gray seals in high-resolution satellite imagery at breeding colonies from the Northeast U.S. to Atlantic Canada. Machine-learning detection is paired with drone surveys that calibrate the satellite counts across colony substrates, extending reliable seal monitoring to sites and scales that conventional aircraft and ground surveys cannot easily reach and complementing NOAA’s aerial survey program.
Projects and Products
- Contaminants monitoring (with Allied Whale): assessing contaminant burdens in marine mammals as an indicator of individual and population health.
- Movement and tracking studies (with NOAA): studying harbor porpoise and harbor seal movement and habitat use in U.S. Navy operating areas.
- Spatially explicit modeling and abundance estimation (with the Alaska Beluga Whale Committee and NOAA): estimating beluga abundance from aerial line-transect survey data in the eastern Beaufort Sea and Amundsen Gulf.
News and Publications
Conn, P.B., and M.C. Ferguson. 2026. Dependence between effort offsets and process intensity in generalized models for count data: spatial models of animal abundance. Environmetrics 37(3):e70098. https://doi.org/10.1002/env.70098
Ferguson, M.C., P.B. Conn, and J.T. Thorson. 2025. Spatially explicit models of density improve estimates of Eastern Bering Sea beluga (Delphinapterus leucas) abundance and distribution from line-transect surveys. PeerJ 13:e20077. https://doi.org/10.7717/peerj.20077
Wethington, M., B.C. Gonçalves, E. Talis, B. Şen, and H.J. Lynch. 2024. Species classification of Antarctic pack-ice seals using very high-resolution imagery. Marine Mammal Science 40(2):e13088. https://doi.org/10.1111/mms.13088
Wethington, M.J., B. Şen, and H.J. Lynch. 2024. Predicting pack-ice seal occupancy of ice floes along the Western Antarctic Peninsula. PLOS ONE 19(12):e0311747. https://doi.org/10.1371/journal.pone.0311747
Clarke, J.T., M.C. Ferguson, A.A. Brower, E. Fujioka, and S. DeLand. 2023. Biologically Important Areas II for cetaceans in U.S. and adjacent waters – Arctic region. Frontiers in Marine Science 10:1040123. https://doi.org/10.3389/fmars.2023.1040123
Ferguson, M.C., S.F. Tóth, J.T. Clarke, A.L. Willoughby, A.A. Brower, and T.P. White. 2023. Biologically Important Areas for bowhead whales (Balaena mysticetus): optimal site selection with integer programming. Frontiers in Marine Science 10:961163. https://doi.org/10.3389/fmars.2023.961163
Harrison, J., M.C. Ferguson, L. New, J. Cleary, C. Curtice, S. DeLand, E. Fujioka, P.N. Halpin, R.B. Tyson Moore, and S.M. Van Parijs. 2023. Biologically Important Areas II for cetaceans within U.S. and adjacent waters – Updates and the application of a new scoring system. Frontiers in Marine Science 10:1081893. https://doi.org/10.3389/fmars.2023.1081893
Crance, J.L., C.L. Berchok, B.M. Kimber, J.M. Harlacher, E.K. Braen, and M.C. Ferguson. 2022. Year-round distribution of bearded seals, Erignathus barbatus, throughout the Alaskan Chukchi and northern Bering Sea. Deep Sea Research Part II: Topical Studies in Oceanography 206:105215. https://doi.org/10.1016/j.dsr2.2022.105215
Ferguson, M.C., D.L. Miller, J.T. Clarke, A.A. Brower, A.L. Willoughby, and A.D. Rotrock. 2022. Spatial modeling, parameter uncertainty, and precision of density estimates from line-transect surveys: a case study with Western Arctic bowhead whales. Paper SC/68d/ASI/01 presented to the IWC Scientific Committee, May 2022.
Gonçalves, B.C., M. Wethington, and H.J. Lynch. 2022. SealNet 2.0: human-level fully-automated pack-ice seal detection in very-high-resolution satellite imagery with CNN model ensembles. Remote Sensing 14(22):5655. https://doi.org/10.3390/rs14225655
Gulland, F.M.D., J.D. Baker, M. Howe, E. LaBrecque, L. Leach, S.E. Moore, R.R. Reeves, and P.O. Thomas. 2022. A review of climate change effects on marine mammals in United States waters: past predictions, observed impacts, current research and conservation imperatives. Climate Change Ecology 3:100054. https://doi.org/10.1016/j.ecochg.2022.100054
Halliday, W.D., N. Le Baron, J.J. Citta, J. Dawson, T. Doniol-Valcroze, M. Ferguson, S.H. Ferguson, S. Fortune, L.A. Harwood, M.P. Heide-Jørgensen, E.V. Lea, L. Quakenbush, B.G. Young, D. Yurkowski, and S.J. Insley. 2022. Overlap between bowhead whales (Balaena mysticetus) and vessel traffic in the North American Arctic and implications for conservation and management. Biological Conservation 276:109820. https://doi.org/10.1016/j.biocon.2022.109820
Ferguson, M.C., J.T. Clarke, A.A. Brower, A.L. Willoughby, and S.R. Okkonen. 2021. Ecological variation in the western Beaufort Sea. Pages 365-379 in J.C. George and J.G.M. Thewissen, editors. The Bowhead Whale Balaena mysticetus: Biology and Human Interactions. Academic Press, London. https://doi.org/10.1016/B978-0-12-818969-6.00024-8
Howe, M., and M.O. Lammers. 2021. Investigating the diel occurrence of odontocetes around the Maui Nui region using passive acoustic techniques. Pacific Science 75(1):147-161. https://doi.org/10.2984/75.1.7
Howe, M., M.O. Lammers, and R.W. Baird. 2019. Participatory science and directed survey methods: a case study with odontocetes in the Maui Nui region of the Hawaiian Islands. Journal of Cetacean Research and Management 20(1):101-109. https://doi.org/10.47536/jcrm.v20i1.235
Lammers, M.O., M. Howe, E. Zang, M. McElligott, A. Engelhaupt, and L. Munger. 2017. Acoustic monitoring of coastal dolphins and their response to naval mine neutralization exercises. Royal Society Open Science 4(12):170558. https://doi.org/10.1098/rsos.170558
Howe, M., M. Castellote, C. Garner, P. McKee, R.J. Small, and R. Hobbs. 2015. Beluga, Delphinapterus leucas, ethogram: a tool for Cook Inlet beluga conservation? Marine Fisheries Review 77(1):32-40. https://doi.org/10.7755/MFR.77.1.3
Mercury in the Global Environment: Marine Mammals. 2017. A series publication by BRI’s Center for Mercury Studies, September 2017.
