Examining the interconnectedness of marine life and habitats
Large marine animals such as bottlenose dolphins, seals and sea lions and whale sharks are important contributors to their ecosystems. The Hubbs-SeaWorld Research Institute (HSWRI) Wildlife Populations program examines the interconnectedness of marine life and habitats towards ensuring healthy ocean ecosystems. Our scientists consider the biological and physical factors that affect marine animals to understand and explain why a particular species occurs in some places and not others, what determines its abundance, and what influences its relationships with other components of the ecosystem.
Our scientists conduct singular and comparative studies of marine and estuarine mammals, fish, sharks, sea turtles and seabirds in tropical, temperate and polar aquatic environments around the world. Catastrophic events such as oil spills and growing concerns about the impacts of climate change highlight the importance of HSWRI’s long-term ecological studies at the California Channel Islands and the Indian River Lagoon system in Florida.
Research focuses on predicting and, when possible, preventing negative impacts to vulnerable marine life from pressures such as increasing human activity (fisheries, coastal development, eco-tourism) and climate change. Traditional techniques like boat surveys, photo-identification and tagging are combined with newer tools such as autonomous aerial and underwater vehicles, integrated population modeling, molecular genetics and stable isotope analysis, to advance ocean and coastal conservation.
Brent S. Stewart Ph.D., J.D.
Primary Research Areas
- Demography and population biology of marine vertebrates documenting the abundance, distribution, life history characteristics and vital rates of marine mammals, fish, sharks, sea turtles and seabirds
- Ecosystem health and resilience: studying the responses of marine and estuarine animals to short-term changes in their environment; making predictions about the potential impact of larger scale perturbations such as ocean acidification and climate change
- Biogeography and foraging ecology of marine vertebrates: evaluating seasonal movements, habitat use, diet, diving behavior and the dynamic influences of environmental change and human activities on these parameters
- Applied ecology: engaging marine vertebrates to collect opportunistic biological and physical oceanographic data; evaluating the impact of enhancement and rehabilitation programs on free-ranging populations of fish and marine mammals
- Human-wildlife interactions: seeking win-win solutions and promoting best practices for human activities to minimize adverse impacts such fisheries interactions, pollution, disturbance (including noise and approaching too closely) and entanglement in or ingestion of marine debris
Demography and population biology of marine vertebrates:
Documenting the abundance, distribution, life history characteristics and vital rates of marine mammals, seabirds, sharks, fish and sea turtles
Ackley, S. F., J. L. Bengtson, P. Boveng, M. Castellini, K. L. Daly, S. Jacobs, G. L. Kooyman, J. Laake, L. Quetin, R. Ross, D. B. Siniff, B. S. Stewart, I. Stirling, J. Torres, and P. K. Yochem). 2003. A topdown multi-disciplinary framework for examining the pack ice ecosystem of the eastern Ross Sea,Antarctica. Polar Record. 39 (210):219-230. (Cover photo).
Akamatsu, T., D. Wang, K. Wang, S. Li, S. Dong, X. Zhao, Z. Wei, J. Barlow, B. S. Stewart, M. Richlen.2008. Estimation of the detection probability for Yangtze finless porpoises (Neophocoena phocaenoides asiaeorientalis) with a passive acoustic method. Journal of the Acoustical Society of America 123:4403-4411.
Castro, A., B.S. Stewart, S. Wilson, R. Hueter, P. Motta, M. Meekan, B. Bowen, S.A. Karl. 2007. Population genetics of Earth’s largest fish, the whale shark (Rhincodon typus). Molecular Ecology 16:5183-5192.
Curtis, C., B. S. Stewart, S. Karl. 2009 Pleistocene population expansion of Antarctic seals. Molecular Ecology, 18:2112-2121.
Durden, W.N., E. D. Stolen, T. A. Jablonski, S. A. Puckett, and M. K. Stolen. 2017. Monitoring seasonal abundance of Indian River Lagoon bottlenose dolphins (Tursiops truncatus) using aerial surveys. Aquatic Mammals.
Durden, W.N., E.D. Stolen, and M.K. Stolen. 2011. Abundance, distribution and group composition of the Indian River Lagoon bottlenose dolphin, Tursiops truncatus, using an aerial survey. Aquatic Mammals 37: 175-186, DOI 10.1578/AM.37.2.2011.175
Mazzoil, M., Gibson, Q., Durden, W.D., Borkowski, R., Biedenbach, G., McKenna, Z., Gordon, N., Brightwell, K., Denny, M., Howells, E., Jakush, J., Moreland, L., Perna, A., and Caldwell, M. 2020. Spatiotemporal Movements of Common Bottlenose Dolphins (Tursiops truncatus truncatus) in Northeast Florida, U.S. Aquatic Mammals, 46(3): 285-300. doi: 10.1578/AM.46.3.2020.285
Stewart, B. S. 1997. Ontogeny of differential migration and sexual segregation in the northern elephant seals, Mirounga angustirostris. Journal of Mammalogy 78:1101-1116.
Weber, D. S., B. S. Stewart, and N. Lehman. 2004. Genetic consequences of a severe population bottleneck in the Guadalupe fur seal (Arctocephalus townsendi). Journal of Heredity 95:144-153. (Cover photo)
Yochem, P. K., J. R. Jehl, B. S. Stewart, S. Thompson, and L. Neel. 1991. Distribution and history of California Gull colonies in Nevada. Western Birds. 22:1-12.
Ecosystem health and resilience:
Studying the responses of marine animals to short-term changes in their environment; making predictions about the potential impact of larger scale perturbations such as ocean acidification and climate change
DeLong, R. L., Antonelis, G. A., Oliver, C. W., Stewart, B. S., Lowry, M. C., and Yochem, P. K. 1991. Effects of the 1982-83 El Niño on several population parameters and diet of California sea lions on the California Channel Islands. Pp. 167-172. In: Pinnipeds and El Niño: response s to environmental stress. (F. Trillmich and K. Ono, eds.). Springer-Verlag, Berlin.
Sleeman, J. C., M. G. Meekan, B. S. Stewart, S. G. Wilson, J. J. Polovina, J. D. Stevens, G. S. Boggs, C. J. A. Bradshaw. 2010. To go or not to go with the flow: Environmental influences on whale shark movement patterns. Journal of Experimental Marine Biology and Ecology, 390: 84-98. (and J. Exp. Mar. Biol. Ecol (2011). 396: 255)
Stewart, B. S., and Yochem, P. K. 1991. Northern elephant seals on the southern California Channel Islands and El Niño. Pp. 234-243. In: Pinnipeds and El Niño: responses to environmental stress. (F. Trillmich and K. Ono, eds.). Springer-Verlag, Berlin.
Tosh, C., N. de Bruyn, J. Steyn, H. Bornemann, J. van den Hoff, B. S. Stewart, J. Plotz, M. Bester. 2015. The importance of seasonal sea-surface height anomalies for foraging juvenile southern elephant seals. Marine Biology 162:2131-2140. DOI 10.1007/s00227-015-2743-4
Biogeography and foraging ecology of marine vertebrates:
Evaluating seasonal movements, habitat use, diet, diving behavior and the dynamic influences of environmental change and human activities on these parameters
Ackley, S. F., J. L. Bengtson, P. Boveng, M. Castellini, K. L. Daly, S. Jacobs, G. L. Kooyman, J. Laake, L. Quetin, R. Ross, D. B. Siniff, B. S. Stewart, I. Stirling, J. Torres, and P. K. Yochem. 2003. A top-down multi-disciplinary framework for examining the pack ice ecosystem of the eastern Ross Sea, Antarctica. Polar Record. 39 (210):219-230. (Cover photo).
Bengtson, J. L., and B. S. Stewart. 1997. Diving patterns of a Ross seal (Ommatophoca rossii) near the eastern coast of the Antarctic Peninsula. Polar Biology, 18:214-218.
Durden, W.N., O’Corry-Crowe, G., Shippee, S., Jablonski, T., Rodgers, S. Mazzoil, M. Howells, E., Hartel, E., Potgieter, B., Londono, C., Moreland, L., Townsend, F., McCulloch, S. and Bossart, G. 2019. Small-scale movement patterns, activity budgets, and association patterns of radio-tagged Indian River Lagoon bottlenose dolphins (Tursiops truncatus). Aquatic Mammals, 45(1): 66-87. doi: 10.1578/AM.45.1.2019.66
Hartel, E.F., Durden, W.N., and O’Corry-Crowe, G. 2020. Testing satellite telemetry within narrow ecosystems: Nocturnal movements and habitat use of bottlenose dolphins within a convoluted estuarine system. Animal Biotelemetry, 8,13.
Linzey, D. W., W. Wiltschko, R. Wiltschko, R. K. J. Lohmann, C. M. F. Lohman, and B. S. Stewart. 2003. Migration and navigation (vertebrates). Pp. 252-256, In: McGraw-Hill Yearbook of Science & Technology. McGraw-Hill, New York. 512 pp.
Rossman, S., P.H. Ostrom, M. Stolen, N.B. Barros, H. Gahdhi,, C. A. Stricker, and R.S. Wells. 2015. Individual specialization in the foraging habits of female bottlenose dolphins living in a trophically diverse and habitat rich estuary. Oecologia 178 (2):415-425.
Stewart, B. S. and R. L. DeLong. 1995. Double migrations of the northern elephant seal. Journal of Mammalogy 76:196-205.
Stewart, B. S., G. A. Antonelis, J. D. Baker, and P.K. Yochem. 2006. Foraging biogeography of Hawaiian monk seals in the northwestern Hawaiian Islands. Atoll Research Bulletin 543:131-145.
Wilson, S. G., J. J. Polovina, B. S. Stewart, and M. Meekan. 2006. Movements of whale sharks tagged at Ningaloo Reef, Western Australia. Marine Biology 148: 1157-1166.
Engaging marine vertebrates to collect opportunistic biological and physical oceanographic data; evaluating the impact of enhancement and rehabilitation programs on free-ranging populations of fish and marine mammals
Brillinger, D.R. and B. S. Stewart. 2010. Stochastic modelling of particle movement with application to marine biology and oceanography. J. Statistical Planning and Inference. 140:3597-3607.
Esson, D.W., H.N. Nollens, T.L. Schmitt, K.J. Fritz, C.A. Simeone, B.S. Stewart. 2015. Aphakic phacoemulsification and automated vitrectomy and post-return monitoring of a rehabilitated harbor seal (Phoca vitulina richardsi) pup. Journal of Zoo and Wildlife Medicine. 46:647-651.
Stewart, B. S. Introduction and background on the rescue, rehabilitation, and scientific studies of JJ, an orphaned California gray whale calf. 2001. Aquatic Mammals 27: 203-208.
Stewart, B. S., J. Harvey, and P. K. Yochem. 2001. Post-release monitoring and tracking of a rehabilitated California gray whale. Aquatic Mammals 27: 294-300.
Zagzebski, K.A., F.M.D. Gulland, M. Haulena, M.E. Lander, D. J.Greig, L. J.Gage, M.B. Hanson, P.K.Yochem and B.S. Stewart. 2006.Twenty-five years of rehabilitation of odontocetes stranded in central and northern California, 1977 to 2002. Aquatic Mammals 32:334-345.
Seeking win-win solutions and promoting best practices for human activities to minimize adverse impacts such fisheries interactions, pollution, disturbance (including noise and approaching too closely) and entanglement in or ingestion of marine debris.
Durden, W.N. The harmful effects of inadvertently conditioning a wild bottlenose dolphin (Tursiops truncatus) to interact with fishing vessels in the Indian River Lagoon, Florida, USA. 2005. Aquatic Mammals, 31(4): 413-419.
Koehler, H. R., B. S. Stewart, P. Carroll, & T. Rice. 2002. Legal instruments for the prevention and management of disposal and loss of fishing gear at sea. Pp. 330-343, In: Proceedings of the International Marine Debris Conference on Derelict Fishing Gear and the Ocean Enviornment. (N. McIntosh, K. Simonds, M. Donohue, C. Brammer, S. Mason, & S. Carbajal, eds. National Marine Sanctuaries, NOAA).
Li, S., T. Akamatsu, D. Wang, K. Wang, S. Dong, X. Zhao, Z. Wei, X. Zhang, B. Taylor, L. A. Barrett, S. T. Turvey, R. R. Reeves, B. S. Stewart, M. Richlen, and J. R. Brandon. Indirect evidence of boat avoidance behavior of Yangtze finless porpoises. Bioacoustics 17: 174-176.
Noke, W. D. and D. K. Odell. Interactions between the Indian River Lagoon blue crab fishery and the bottlenose dolphin, Tursiops truncatus. 2002. Marine Mammal Science 18: 819-832.
Stolen, M.K., W.N. Durden, T. Mazza, N. Barros, J. St. Leger. 2013. Effects of recreational fishing gear on bottlenose dolphins (Tursiops truncatus) in the Indian River Lagoon system, Florida. Marine Mammal Science 29: 356-364
Turvey, S. T., R. L. Pitman, B. L. Taylor, J. Barlow, T. Akamatsu, L. A. Barrett, X. Zhao, R. R. Reeves, B. S. Stewart, K. Wang, Z. Wei, X. Zhang, M. Richlen, T. Pusser, J. R. Brandon, and D. Wang. 2007. First human-caused extinction of a cetacean species? Biology Letters 3:537-540.
Ylitalo, G. M., M. Myers, B. S. Stewart, P. K. Yochem, R. Braun, L. Kashinsky, D. Boyd, G. A. Antonelis, S. Atkinson, L. A. Woodward, A. Aguirre, and M. M. Krahn. 2008. Organochlorine contaminants in endangered Hawaiian monk seals (Monachus schauinslandi) from four Northwestern Hawaiian Islands subpopulations. Marine Pollution Bulletin. 56:231-244. Doi:10.1016/jmarpolbul.207.09.034.