USAP-DC

Abstract
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

Marine mammals of the Southern Ocean have evolved diverse life history patterns and foraging strategies to accommodate extreme fluctuations in the physical and biological environment. In light of ongoing climate change and the dramatic shifts in the extent and persistence of sea ice in the Ross Sea, it is critical to understand how Weddell seals, Leptonychotes weddellii, a key apex predator, select and utilize foraging habitats. Recent advances in satellite-linked animal-borne conductivity, temperature and depth (CTD) tags make it possible to simultaneously collect data on seal locations, their diving patterns, and the temperature and salinity profiles of the water columns they utilize. In other ecosystems, such data have revealed that marine predators selectively forage in areas where currents and fronts serve to locally concentrate prey resources, and that these conditions are required to sustain populations. Weddell seals will be studied in McMurdo Sound and at Terra Nova Bay, Ross Sea and will provide the first new data on Weddell seal winter diving behavior and habitat use in almost two decades. The relationship between an animal's diving behavior and physical habitat has enormous potential to enhance monitoring studies and to provide insight into how changes in ice conditions (due either to warming or the impact of large icebergs, such as B15) might impact individual time budgets and foraging success. The second thrust of this project is to use the profiles obtained from CTD seal tags to model the physical oceanography of this region. Current mathematical models of physical oceanographic processes in the Southern Ocean are directed at better understanding the role that it plays in global climate processes, and the linkages between physical and biological oceanographic processes. However, these efforts are limited by the scarcity of oceanographic data at high latitudes in the winter months; CTD tags deployed on animals will collect data at sufficient spatial and temporal resolution to improve data density. The project will contribute to two IPY endorsed initiatives: MEOP (Marine Mammals as Explorers of the Ocean Pole to Pole) and CAML (Census of Antarctic Marine Life). In addition, the highly visual nature of the data and analysis lends itself to public and educational display and outreach, particularly as they relate to global climate change, and we have collaborations with undergraduate and graduate training programs, the Seymour Marine Discovery Center, and the ARMADA program to foster these broader impacts.

Person	Role
Burns, Jennifer	Investigator
Hofmann, Eileen	Investigator
Costa, Daniel	Investigator

Antarctic Organisms and Ecosystems	Award # 0838937
Antarctic Organisms and Ecosystems	Award # 0838911
Antarctic Organisms and Ecosystems	Award # 0838892

NSF-ANT08-38911
NSF-ANT08-38892_1

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea	None	exist
USAP-DC	Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea	None	exist

1. Hückstädt, L. A., Tift, M. S., Riet-Sapriza, F., Franco-Trecu, V., Baylis, A. M. M., Orben, R. A., … Costa, D. P. (2016). Regional variability in diving physiology and behavior in a widely distributed air-breathing marine predator, the South American sea lion Otaria byronia. Journal of Experimental Biology. (doi:10.1242/jeb.138677)
2. Shero, M. R., Goetz, K. T., Costa, D. P., & Burns, J. M. (2018). Temporal changes in Weddell seal dive behavior over winter: Are females increasing foraging effort to support gestation? Ecology and Evolution, 8(23), 11857–11874. (doi:10.1002/ece3.4643)
3. Abrahms, B., Hazen, E. L., Bograd, S. J., Brashares, J. S., Robinson, P. W., Scales, K. L., … Costa, D. P. (2017). Climate mediates the success of migration strategies in a marine predator. Ecology Letters, 21(1), 63–71. (doi:10.1111/ele.12871)
4. Shero, M. R., Krotz, R. T., Costa, D. P., Avery, J. P., & Burns, J. M. (2015). How do overwinter changes in body condition and hormone profiles influence Weddell seal reproductive success? Functional Ecology, 29(10), 1278–1291. (doi:10.1111/1365-2435.12434)
5. Goetz, K. T., Burns, J. M., Hückstӓdt, L. A., Shero, M. R., & Costa, D. P. (2017). Temporal variation in isotopic composition and diet of Weddell seals in the western Ross Sea. Deep Sea Research Part II: Topical Studies in Oceanography, 140, 36–44. (doi:10.1016/j.dsr2.2016.05.017)
6. Murphy, E. J., Cavanagh, R. D., Drinkwater, K. F., Grant, S. M., Heymans, J. J., Hofmann, E. E., … Johnston, N. M. (2016). Understanding the structure and functioning of polar pelagic ecosystems to predict the impacts of change. Proceedings of the Royal Society B: Biological Sciences, 283(1844), 20161646. (doi:10.1098/rspb.2016.1646)
7. Abrahms, B., Scales, K. L., Hazen, E. L., Bograd, S. J., Schick, R. S., Robinson, P. W., & Costa, D. P. (2018). Mesoscale activity facilitates energy gain in a top predator. Proceedings of the Royal Society B: Biological Sciences, 285(1885), 20181101. (doi:10.1098/rspb.2018.1101)
8. Hückstädt, L. A., McCarthy, M. D., Koch, P. L., & Costa, D. P. (2017). What difference does a century make? Shifts in the ecosystem structure of the Ross Sea, Antarctica, as evidenced from a sentinel species, the Weddell seal. Proceedings of the Royal Society B: Biological Sciences, 284(1861), 20170927. (doi:10.1098/rspb.2017.0927)
9. Piñones, A., Hofmann, E. E., Costa, D. P., Goetz, K., Burns, J. M., Roquet, F., … Klinck, J. M. (2019). Hydrographic variability along the inner and mid-shelf region of the western Ross Sea obtained using instrumented seals. Progress in Oceanography, 174, 131–142. (doi:10.1016/j.pocean.2019.01.003)
10. Frazer, E. K., Langhorne, P. J., Williams, M. J. M., Goetz, K. T., & Costa, D. P. (2018). A method for correcting seal-borne oceanographic data and application to the estimation of regional sea ice thickness. Journal of Marine Systems, 187, 250–259. (doi:10.1016/j.jmarsys.2018.08.002)
11. Shero, M. R., Costa, D. P., & Burns, J. M. (2015). Scaling matters: incorporating body composition into Weddell seal seasonal oxygen store comparisons reveals maintenance of aerobic capacities. Journal of Comparative Physiology B, 185(7), 811–824. (doi:10.1007/s00360-015-0922-8)
12. Pearson, L. E., Liwanag, H. E. M., Hammill, M. O., & Burns, J. M. (2014). To each its own: Thermoregulatory strategy varies among neonatal polar phocids. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 178, 59–67. (doi:10.1016/j.cbpa.2014.08.006)